diff --git a/lib/arborist/build-ideal-tree.js b/lib/arborist/build-ideal-tree.js
index bf78d57d3..ba8101348 100644
--- a/lib/arborist/build-ideal-tree.js
+++ b/lib/arborist/build-ideal-tree.js
@@ -5,6 +5,7 @@ const npa = require('npm-package-arg')
 const pacote = require('pacote')
 const semver = require('semver')
 const pickManifest = require('npm-pick-manifest')
+const mapWorkspaces = require('@npmcli/map-workspaces')
 
 const calcDepFlags = require('../calc-dep-flags.js')
 const Shrinkwrap = require('../shrinkwrap.js')
@@ -46,6 +47,7 @@ const _nodeFromSpec = Symbol('nodeFromSpec')
 const _fetchManifest = Symbol('fetchManifest')
 const _problemEdges = Symbol('problemEdges')
 const _manifests = Symbol('manifests')
+const _mapWorkspaces = Symbol('mapWorkspaces')
 const _linkFromSpec = Symbol('linkFromSpec')
 const _loadPeerSet = Symbol('loadPeerSet')
 // shared symbols so we can hit them with unit tests
@@ -203,6 +205,7 @@ module.exports = cls => class IdealTreeBuilder extends Tracker(Virtual(Actual(cl
             .then(meta => Object.assign(root, {meta}))
         : this.loadVirtual({ root }))
 
+      .then(tree => this[_mapWorkspaces](tree))
       .then(tree => {
         // null the virtual tree, because we're about to hack away at it
         // if you want another one, load another copy.
@@ -234,9 +237,19 @@ module.exports = cls => class IdealTreeBuilder extends Tracker(Virtual(Actual(cl
       optional: false,
       global: this[_global],
       legacyPeerDeps: this.legacyPeerDeps,
+      hasWorkspaces: !!pkg.workspaces,
     })
   }
 
+  [_mapWorkspaces] (node) {
+    return mapWorkspaces({ cwd: node.path, pkg: node.package })
+      .then(workspaces => {
+        if (workspaces.size)
+          node.workspaces = workspaces
+        return node
+      })
+  }
+
   // process the add/rm requests by modifying the root node, and the
   // update.names request by queueing nodes dependent on those named.
   [_applyUserRequests] (options) {
diff --git a/lib/arborist/load-virtual.js b/lib/arborist/load-virtual.js
index 946e88d8c..0b1d0f91a 100644
--- a/lib/arborist/load-virtual.js
+++ b/lib/arborist/load-virtual.js
@@ -1,6 +1,7 @@
 // mixin providing the loadVirtual method
 
 const {resolve} = require('path')
+const mapWorkspaces = require('@npmcli/map-workspaces')
 
 const consistentResolve = require('../consistent-resolve.js')
 const Shrinkwrap = require('../shrinkwrap.js')
@@ -15,6 +16,7 @@ const resolveLinks = Symbol('resolveLinks')
 const assignParentage = Symbol('assignParentage')
 const loadNode = Symbol('loadVirtualNode')
 const loadLink = Symbol('loadVirtualLink')
+const loadWorkspaces = Symbol('loadWorkspaces')
 
 module.exports = cls => class VirtualLoader extends cls {
   constructor (options) {
@@ -39,7 +41,10 @@ module.exports = cls => class VirtualLoader extends cls {
       // when building the ideal tree, we pass in a root node to this function
       // otherwise, load it from the root package in the lockfile
       const {
-        root = this[loadNode]('', s.data.packages[''] || {})
+        root = this[loadWorkspaces](
+          this[loadNode]('', s.data.packages[''] || {}),
+          s
+        )
       } = options
 
       return this[loadFromShrinkwrap](s, root)
@@ -160,6 +165,16 @@ module.exports = cls => class VirtualLoader extends cls {
     return node
   }
 
+  [loadWorkspaces] (node, s) {
+    const workspaces = mapWorkspaces.virtual({
+      cwd: node.path,
+      lockfile: s.data
+    })
+    if (workspaces.size)
+      node.workspaces = workspaces
+    return node
+  }
+
   [loadLink] (location, targetLoc, target, meta) {
     const path = resolve(this.path, location)
     const link = new Link({
diff --git a/lib/edge.js b/lib/edge.js
index 29003b64a..a0bb7a432 100644
--- a/lib/edge.js
+++ b/lib/edge.js
@@ -1,6 +1,7 @@
 // An edge in the dependency graph
 // Represents a dependency relationship of some kind
 
+const npa = require('npm-package-arg')
 const depValid = require('./dep-valid.js')
 const _from = Symbol('_from')
 const _to = Symbol('_to')
@@ -18,6 +19,7 @@ const types = new Set([
   'optional',
   'peer',
   'peerOptional',
+  'workspace'
 ])
 
 class Edge {
@@ -26,6 +28,10 @@ class Edge {
 
     if (typeof spec !== 'string')
       throw new TypeError('must provide string spec')
+
+    if (type === 'workspace' && npa(spec).type !== 'directory')
+      throw new TypeError('workspace edges must be a symlink')
+
     this[_spec] = spec
 
     if (accept !== undefined) {
diff --git a/lib/node.js b/lib/node.js
index b065beae2..f17e61dc5 100644
--- a/lib/node.js
+++ b/lib/node.js
@@ -46,6 +46,7 @@ const _fsParent = Symbol('_fsParent')
 const _reloadEdges = Symbol('_reloadEdges')
 const _loadType = Symbol('_loadType')
 const _loadDepType = Symbol('_loadDepType')
+const _loadWorkspaces = Symbol('_loadWorkspaces')
 const _reloadNamedEdges = Symbol('_reloadNamedEdges')
 // overridden by Link class
 const _loadDeps = Symbol.for('Arborist.Node._loadDeps')
@@ -55,6 +56,7 @@ const _refreshTopMeta = Symbol('_refreshTopMeta')
 const _refreshPath = Symbol('_refreshPath')
 const _delistFromMeta = Symbol('_delistFromMeta')
 const _global = Symbol.for('global')
+const _workspaces = Symbol('_workspaces')
 
 const relpath = require('./relpath.js')
 const consistentResolve = require('./consistent-resolve.js')
@@ -93,6 +95,8 @@ class Node {
     // true if part of a global install
     this[_global] = global
 
+    this[_workspaces] = null
+
     this.errors = error ? [error] : []
     const pkg = normalize(options.pkg || {})
 
@@ -209,6 +213,22 @@ class Node {
     return this.global && this.parent.isRoot
   }
 
+  get workspaces() {
+    return this[_workspaces]
+  }
+
+  set workspaces(workspaces) {
+    // deletes edges if they already exists
+    if (this[_workspaces])
+      for (const [name, path] of this[_workspaces].entries()) {
+        if (!workspaces.has(name)) this.edgesOut.get(name).detach()
+      }
+
+    this[_workspaces] = workspaces
+    this[_loadWorkspaces]()
+    this[_loadDeps]()
+  }
+
   get binPaths () {
     if (!this.parent)
       return []
@@ -242,6 +262,7 @@ class Node {
     }
 
     this[_package] = pkg
+    this[_loadWorkspaces]()
     this[_loadDeps]()
     // do a hard reload, since the dependents may now be valid or invalid
     // as a result of the package change.
@@ -334,6 +355,14 @@ class Node {
     return this[_root] || this
   }
 
+  [_loadWorkspaces] () {
+    if (!this[_workspaces]) return
+
+    for (const [name, path] of this[_workspaces].entries()) {
+      new Edge({ from: this, name, spec: `file:${path}`, type: 'workspace' })
+    }
+  }
+
   [_loadDeps] () {
     // Caveat!  Order is relevant!
     // packages in optionalDependencies and prod/peer/dev are
diff --git a/lib/shrinkwrap.js b/lib/shrinkwrap.js
index 29d761d05..aa094c8e6 100644
--- a/lib/shrinkwrap.js
+++ b/lib/shrinkwrap.js
@@ -104,6 +104,7 @@ const pkgMetaKeys = [
   'hasInstallScript',
   'bin',
   'deprecated',
+  'workspaces',
 ]
 
 const nodeMetaKeys = [
diff --git a/notes/workspace.md b/notes/workspace.md
index 289705a77..d8c09e937 100644
--- a/notes/workspace.md
+++ b/notes/workspace.md
@@ -1,60 +1,181 @@
 # workspaces
 
-A few ways to do this:
-
-## Option A: link packages to root `node_modules`, install others
-
-This is how yarn does it.  Probably better.
+Conceptual install example:
 
 ```
 root
-+-- app (uses a, b, c, i)
-|   +-- node_modules
-|       +-- i
 +-- node_modules
-|   +-- app => root/app
-|   +-- a => root/pkgs/a
-|   +-- b => root/pkgs/b
-|   +-- c => root/pkgs/c
+|   +-- app => app
+|   +-- a => pkgs/a
+|   +-- b => pkgs/b
+|   +-- c => pkgs/c
+|   +-- x
+|   +-- y
+|   +-- z
+|   +-- i
+|   +-- n ?
+|   +-- j
+|   +-- k
++-- app
 +-- pkgs
-    +-- a (b, c, x)
+    +-- a (b, c, x, m@file:./m)
+    |   +-- m (n)
+    |   |   +-- node_modules
+    |   |       +-- n ?
     |   +-- node_modules
+    |       +-- n ?
+    |       +-- m => pkgs/a/m
     |       +-- x
+    |       +-- b => pkgs/b
+    |       +-- c => pkgs/c
     +-- b (a, c, y)
-    |   +-- node_modules
-    |       +-- y
     +-- c (a, b, z)
-        +-- node_modules
-            +-- z
+    +-- w (nested workspace)
+        +-- pkgs
+            +-- j
+            +-- k
 ```
 
-## Option B: Link packages into one another
+- `root/package.json`:
 
-Kind of a mess.  Not as good, but should still be supported, because that's
-what pre-arborist `npm link ../foo` would generate.
+```json
+{
+  "workspaces": [
+    "pkgs/*",
+    "app"
+  ]
+}
+```
+
+root `Node`
+
+- be aware it's a **Top-level workspace**
+- 4 Edges in edgesOut with type=workspace, referencing workspace children
+  - that means we create a link node in root.children.get('app')
+    targetting `./app` Node, etc.
+- during buildIdeal:
+  - need to know that app is in root's workspace
+    - app.wsParent = root
+    - root.wsChildren.add(app)
+  - if any dep CAN be satisfied by a named dep in the workspace, then
+    create a Link targetting that workspace child node
+      - resolving: _first_ check this.wsParent.get('dep-name'), and if
+        that's ok, then resolve with a link to that target.
+  - no hoisting by default: when doing `_canPlaceDep`, if target is
+    node.wsParent, AND we're not hoisting, THEN: return CONFLICT
+- When setting Node.parent or Node.fsParent, set wsParent = parent.wsParent
+
+## Questions / Thoughts
+- What a Workspace node class does?
+  - Add metadata to lock files
+  - Glob only relevant for loadActual
+- maybe wsParent wsChildren
+- when creating
+- start with loadActual
+  - loadActual.loadFSNode
+  - on check for path is real add another check to make load from/as a workspace
+- General impl ideas
+  - Do we support an opt-out flag?
+  - Do we want to add extra top-level commands to the cli?
+    - `npm workspaces info`: Retrieves workspaces locations (might be useful for tooling)
+  - What do we do with binaries? Do we only link bins for workspaces that are defined as a top-level dep?
+  - In order to support subsets of packages the way Wes been advocating for, instead of supporting adjacent folders with package.json defining different workspaces, what if we were to support a different workspaces config definition within the top-level package.json - maybe something that allows for definition of subsets? something in the likes of:
+  ```
+  "workspaces": [
+    "packages": {
+      "set-a": [
+        "packages/*"
+      ],
+      "set-b": [
+        "express/express-namespace",
+        "express/express"
+      ]
+    }
+  ]
+  ```
+  - But then we'd need a way for commands to be aware of these subsets...
+
+## Registry vs workspace relationship:
 
 ```
-root
-+-- pkgs
-    +-- app
-    |   +-- node_modules
-    |       +-- a => pkgs/a
-    |       +-- b => pkgs/b
-    |       +-- c => pkgs/c
-    |       +-- i
-    +-- a (b, c, x)
-    |   +-- node_modules
-    |       +-- x
-    |       +-- b => pkgs/b
-    |       +-- c => pkgs/c
-    +-- b (a, c, y)
-    |   +-- node_modules
-    |       +-- y
-    |       +-- a => pkgs/a
-    |       +-- c => pkgs/c
-    +-- c (a, b, z)
+given that registry has latest: a@1.1.0
+
+workspace-root
++-- packages
+    +-- a (a@1.0.1)
+    +-- b (a@^1.0.0)
+
+npm install
+
+workspace-root
++-- packages
+    +-- a (a@1.0.1)
+    +-- b (a@^1.0.0)
+        +-- node_modules
+            +-- a -> ../../a
+
+workspaces always prefer to install a nested package if semver is satisfied
+```
+
+```
+given that registry has latest: a@2.0.0
+
+workspace-root
++-- packages
+    +-- a@1.0.1
+    +-- b (a@^2.0.0)
+
+npm install
+
+workspace-root
++-- packages
+    +-- a@1.0.1
+    +-- b (a@^2.0.0)
         +-- node_modules
-            +-- z
-            +-- a => pkgs/a
-            +-- b => pkgs/b
+            +-- a@2.0.0
+
+workspaces will try to install deps from registry if no satisfying semver version was found within its nested packages
 ```
+
+## Implementation
+
+### Build Ideal Tree
+
+1. Read list of "workpaces" from `package.json`
+2. Turn globs into actual locations, retrieve the final list of workspaces paths
+3. Arborist needs to be made aware of the list of worskpaces paths
+  1. Workspace info parsed (steps 1 and 2) needs to be attached before build ideal tree
+  2. On building ideal tree, checks against existing workspaces to append them as child nodes
+  3. Edge needs to support a `workspace` type
+  4. Edge `satisfiedBy` and/or the `dep-valid` module needs to check against the available workspaces
+  5. `edgesOut` with `type: workspace`
+4. Represent a workspace node within a tree - is it just `node.workspace` ?
+
+NOTE:
+- Now the build ideal tree is reading fs other than `package.json` and `package-lock`
+
+### Load Virtual
+
+1. How to figure out all the structure of workspaces form a pakcage-lock
+  1. How it gets saved?
+  2. How to build the virtual tree out of reading package-lock
+2. maybe support a subset of glob? we need to optimize mapWorkspace regardless
+3. lib/shrinkwrap.js has to be aware of workspaces and the structure
+  1. Reading from lockfile might render nodes extraneous?
+  2. include workspaces map into package-lock files
+  3. loadVirtual reads from the lock file and put nodes in the right place
+
+
+### Reify
+
+1. Correctly symlink workspaces to its dependants `node_modules`
+
+## Open Ended Questions
+
+- Maybe do not hoist workspace dependencies by default?
+
+## Missing:
+- Nested workspaces
+  - Add support to `mapWorkspaces` in buildIdealTree `_linkFromSpec`
+  - Tests
+- Test case with a mixed relationship between `file:` deps and workspaces
diff --git a/package-lock.json b/package-lock.json
index d309cbb41..50e8223ca 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -180,6 +180,17 @@
         "readdir-scoped-modules": "^1.1.0"
       }
     },
+    "@npmcli/map-workspaces": {
+      "version": "0.0.0-pre.1",
+      "resolved": "https://registry.npmjs.org/@npmcli/map-workspaces/-/map-workspaces-0.0.0-pre.1.tgz",
+      "integrity": "sha512-IovEVdr17hW/Stt0kpPjz1r0ZxRX3RGah7ww3tQpi5NtyOapJwbUffWuWETyQkOjud5soC45mnjOOBtfTggtng==",
+      "requires": {
+        "@npmcli/name-from-folder": "^1.0.1",
+        "glob": "^7.1.6",
+        "minimatch": "^3.0.4",
+        "read-package-json-fast": "^1.1.3"
+      }
+    },
     "@npmcli/name-from-folder": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/@npmcli/name-from-folder/-/name-from-folder-1.0.1.tgz",
diff --git a/package.json b/package.json
index e73c6f571..f9cc794b4 100644
--- a/package.json
+++ b/package.json
@@ -5,6 +5,7 @@
   "dependencies": {
     "@npmcli/installed-package-contents": "^1.0.5",
     "@npmcli/name-from-folder": "^1.0.1",
+    "@npmcli/map-workspaces": "0.0.0-pre.1",
     "@npmcli/run-script": "^1.3.1",
     "bin-links": "^2.1.2",
     "json-stringify-nice": "^1.1.1",
diff --git a/tap-snapshots/test-arborist-build-ideal-tree.js-TAP.test.js b/tap-snapshots/test-arborist-build-ideal-tree.js-TAP.test.js
index 5cf4e43be..4ee8d799f 100644
--- a/tap-snapshots/test-arborist-build-ideal-tree.js-TAP.test.js
+++ b/tap-snapshots/test-arborist-build-ideal-tree.js-TAP.test.js
@@ -50318,3 +50318,961 @@ Node {
   "resolved": null,
 }
 `
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should ignore nested node_modules folders > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-ignore-nm/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-ignore-nm/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-ignore-nm",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should install a simple example > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-simple/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-simple/b",
+          "type": "workspace",
+        },
+        Edge {
+          "from": "a",
+          "name": "b",
+          "spec": "^1.0.0",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../b",
+      "target": Object {
+        "name": "b",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-simple/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-simple/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "edgesOut": Map {
+        "b" => Edge {
+          "name": "b",
+          "spec": "^1.0.0",
+          "to": "node_modules/b",
+          "type": "prod",
+        },
+      },
+      "location": "a",
+      "name": "a",
+      "resolved": null,
+    },
+    Node {
+      "location": "b",
+      "name": "b",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-simple",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should install a simple scoped pkg example > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "@ruyadorno/scoped-a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "@ruyadorno/scoped-a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-scoped-pkg/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/@ruyadorno/scoped-a",
+      "name": "@ruyadorno/scoped-a",
+      "resolved": "file:../../packages/a",
+      "target": Object {
+        "name": "@ruyadorno/scoped-a",
+        "parent": null,
+      },
+    },
+    "@ruyadorno/scoped-b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "@ruyadorno/scoped-b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-scoped-pkg/packages/b",
+          "type": "workspace",
+        },
+        Edge {
+          "from": "packages/a",
+          "name": "@ruyadorno/scoped-b",
+          "spec": "^1.0.0",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/@ruyadorno/scoped-b",
+      "name": "@ruyadorno/scoped-b",
+      "resolved": "file:../../packages/b",
+      "target": Object {
+        "name": "@ruyadorno/scoped-b",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "@ruyadorno/scoped-a" => Edge {
+      "name": "@ruyadorno/scoped-a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-scoped-pkg/packages/a",
+      "to": "node_modules/@ruyadorno/scoped-a",
+      "type": "workspace",
+    },
+    "@ruyadorno/scoped-b" => Edge {
+      "name": "@ruyadorno/scoped-b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-scoped-pkg/packages/b",
+      "to": "node_modules/@ruyadorno/scoped-b",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "edgesOut": Map {
+        "@ruyadorno/scoped-b" => Edge {
+          "name": "@ruyadorno/scoped-b",
+          "spec": "^1.0.0",
+          "to": "node_modules/@ruyadorno/scoped-b",
+          "type": "prod",
+        },
+      },
+      "location": "packages/a",
+      "name": "@ruyadorno/scoped-a",
+      "resolved": null,
+    },
+    Node {
+      "location": "packages/b",
+      "name": "@ruyadorno/scoped-b",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-scoped-pkg",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should install conflicting dep versions > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-conflicting-versions/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "abbrev" => Node {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "abbrev",
+          "spec": "^1.1.1",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-conflicting-versions/packages/b",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../packages/b",
+      "target": Object {
+        "name": "b",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-conflicting-versions/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "abbrev" => Edge {
+      "name": "abbrev",
+      "spec": "^1.1.1",
+      "to": "node_modules/abbrev",
+      "type": "prod",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-conflicting-versions/packages/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "children": Map {
+        "abbrev" => Node {
+          "edgesIn": Set {
+            Edge {
+              "from": "packages/a",
+              "name": "abbrev",
+              "spec": "=1.0.4",
+              "type": "prod",
+            },
+          },
+          "location": "packages/a/node_modules/abbrev",
+          "name": "abbrev",
+          "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.0.4.tgz",
+        },
+      },
+      "edgesOut": Map {
+        "abbrev" => Edge {
+          "name": "abbrev",
+          "spec": "=1.0.4",
+          "to": "packages/a/node_modules/abbrev",
+          "type": "prod",
+        },
+      },
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+    Node {
+      "children": Map {
+        "abbrev" => Node {
+          "edgesIn": Set {
+            Edge {
+              "from": "packages/b",
+              "name": "abbrev",
+              "spec": "=1.1.0",
+              "type": "prod",
+            },
+          },
+          "location": "packages/b/node_modules/abbrev",
+          "name": "abbrev",
+          "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.0.tgz",
+        },
+      },
+      "edgesOut": Map {
+        "abbrev" => Edge {
+          "name": "abbrev",
+          "spec": "=1.1.0",
+          "to": "packages/b/node_modules/abbrev",
+          "type": "prod",
+        },
+      },
+      "location": "packages/b",
+      "name": "b",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-conflicting-versions",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should install from registry on version not satisfied > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-version-unsatisfied/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "abbrev" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "abbrev",
+          "spec": "file:{CWD}/test/fixtures/workspaces-version-unsatisfied/packages/abbrev",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "resolved": "file:../packages/abbrev",
+      "target": Object {
+        "name": "abbrev",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-version-unsatisfied/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "abbrev" => Edge {
+      "name": "abbrev",
+      "spec": "file:{CWD}/test/fixtures/workspaces-version-unsatisfied/packages/abbrev",
+      "to": "node_modules/abbrev",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "children": Map {
+        "abbrev" => Node {
+          "edgesIn": Set {
+            Edge {
+              "from": "packages/a",
+              "name": "abbrev",
+              "spec": "=1.1.1",
+              "type": "prod",
+            },
+          },
+          "location": "packages/a/node_modules/abbrev",
+          "name": "abbrev",
+          "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+        },
+      },
+      "edgesOut": Map {
+        "abbrev" => Edge {
+          "name": "abbrev",
+          "spec": "=1.1.1",
+          "to": "packages/a/node_modules/abbrev",
+          "type": "prod",
+        },
+      },
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+    Node {
+      "location": "packages/abbrev",
+      "name": "abbrev",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-version-unsatisfied",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should install shared dependencies into root folder > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "abbrev" => Node {
+      "edgesIn": Set {
+        Edge {
+          "from": "packages/a",
+          "name": "abbrev",
+          "spec": "^1.1.1",
+          "type": "prod",
+        },
+        Edge {
+          "from": "packages/b",
+          "name": "abbrev",
+          "spec": "^1.1.1",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps/packages/b",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../packages/b",
+      "target": Object {
+        "name": "b",
+        "parent": null,
+      },
+    },
+    "c" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "c",
+          "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps/packages/c",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/c",
+      "name": "c",
+      "resolved": "file:../packages/c",
+      "target": Object {
+        "name": "c",
+        "parent": null,
+      },
+    },
+    "uuid" => Node {
+      "edgesIn": Set {
+        Edge {
+          "from": "packages/c",
+          "name": "uuid",
+          "spec": "=3.3.3",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/uuid",
+      "name": "uuid",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.3.3.tgz",
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps/packages/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+    "c" => Edge {
+      "name": "c",
+      "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps/packages/c",
+      "to": "node_modules/c",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "edgesOut": Map {
+        "abbrev" => Edge {
+          "name": "abbrev",
+          "spec": "^1.1.1",
+          "to": "node_modules/abbrev",
+          "type": "prod",
+        },
+      },
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+    Node {
+      "edgesOut": Map {
+        "abbrev" => Edge {
+          "name": "abbrev",
+          "spec": "^1.1.1",
+          "to": "node_modules/abbrev",
+          "type": "prod",
+        },
+      },
+      "location": "packages/b",
+      "name": "b",
+      "resolved": null,
+    },
+    Node {
+      "edgesOut": Map {
+        "uuid" => Edge {
+          "name": "uuid",
+          "spec": "=3.3.3",
+          "to": "node_modules/uuid",
+          "type": "prod",
+        },
+      },
+      "location": "packages/c",
+      "name": "c",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-shared-deps",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should install workspace transitive dependencies > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-transitive-deps/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "once" => Node {
+      "dev": true,
+      "edgesIn": Set {
+        Edge {
+          "from": "packages/a",
+          "name": "once",
+          "spec": "^1.4.0",
+          "type": "dev",
+        },
+      },
+      "edgesOut": Map {
+        "wrappy" => Edge {
+          "name": "wrappy",
+          "spec": "1",
+          "to": "node_modules/wrappy",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/once",
+      "name": "once",
+      "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
+    },
+    "wrappy" => Node {
+      "dev": true,
+      "edgesIn": Set {
+        Edge {
+          "from": "node_modules/once",
+          "name": "wrappy",
+          "spec": "1",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/wrappy",
+      "name": "wrappy",
+      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-transitive-deps/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "edgesOut": Map {
+        "once" => Edge {
+          "name": "once",
+          "spec": "^1.4.0",
+          "to": "node_modules/once",
+          "type": "dev",
+        },
+      },
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-transitive-deps",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should link top level nested workspaces > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-top-level-link/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-top-level-link/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-top-level-link",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should prefer linking nested workspaces > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-prefer-linking/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "abbrev" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "abbrev",
+          "spec": "file:{CWD}/test/fixtures/workspaces-prefer-linking/packages/abbrev",
+          "type": "workspace",
+        },
+        Edge {
+          "from": "packages/a",
+          "name": "abbrev",
+          "spec": "*",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "resolved": "file:../packages/abbrev",
+      "target": Object {
+        "name": "abbrev",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-prefer-linking/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "abbrev" => Edge {
+      "name": "abbrev",
+      "spec": "file:{CWD}/test/fixtures/workspaces-prefer-linking/packages/abbrev",
+      "to": "node_modules/abbrev",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "edgesOut": Map {
+        "abbrev" => Edge {
+          "name": "abbrev",
+          "spec": "*",
+          "to": "node_modules/abbrev",
+          "type": "prod",
+        },
+      },
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+    Node {
+      "location": "packages/abbrev",
+      "name": "abbrev",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-prefer-linking",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/build-ideal-tree.js TAP workspaces should work with files spec > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-with-files-spec/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-with-files-spec/packages/b",
+          "type": "workspace",
+        },
+        Edge {
+          "from": "d",
+          "name": "b",
+          "spec": "^1.0.0",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../packages/b",
+      "target": Object {
+        "name": "b",
+        "parent": null,
+      },
+    },
+    "c" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "c",
+          "spec": "file:packages/c",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/c",
+      "name": "c",
+      "resolved": "file:../packages/c",
+      "target": Object {
+        "name": "c",
+        "parent": null,
+      },
+    },
+    "d" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "d",
+          "spec": "file:d",
+          "type": "prod",
+        },
+        Edge {
+          "from": "packages/a",
+          "name": "d",
+          "spec": "^1.0.0",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/d",
+      "name": "d",
+      "resolved": "file:../d",
+      "target": Object {
+        "name": "d",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-with-files-spec/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-with-files-spec/packages/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+    "c" => Edge {
+      "name": "c",
+      "spec": "file:packages/c",
+      "to": "node_modules/c",
+      "type": "prod",
+    },
+    "d" => Edge {
+      "name": "d",
+      "spec": "file:d",
+      "to": "node_modules/d",
+      "type": "prod",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "edgesOut": Map {
+        "b" => Edge {
+          "name": "b",
+          "spec": "^1.0.0",
+          "to": "node_modules/b",
+          "type": "prod",
+        },
+      },
+      "location": "d",
+      "name": "d",
+      "resolved": null,
+    },
+    Node {
+      "edgesOut": Map {
+        "d" => Edge {
+          "name": "d",
+          "spec": "^1.0.0",
+          "to": "node_modules/d",
+          "type": "prod",
+        },
+      },
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+    Node {
+      "location": "packages/b",
+      "name": "b",
+      "resolved": null,
+    },
+    Node {
+      "location": "packages/c",
+      "name": "c",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "workspaces-with-files-spec",
+  "resolved": null,
+}
+`
diff --git a/tap-snapshots/test-arborist-load-virtual.js-TAP.test.js b/tap-snapshots/test-arborist-load-virtual.js-TAP.test.js
index c480aaa21..5b9f13887 100644
--- a/tap-snapshots/test-arborist-load-virtual.js-TAP.test.js
+++ b/tap-snapshots/test-arborist-load-virtual.js-TAP.test.js
@@ -13552,3 +13552,541 @@ Node {
   "resolved": null,
 }
 `
+
+exports[`test/arborist/load-virtual.js TAP workspaces load a simple example > virtual tree with multiple bundles 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-simple-virtual/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../a",
+      "target": Object {
+        "name": "a",
+        "parent": undefined,
+      },
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-simple-virtual/b",
+          "type": "workspace",
+        },
+        Edge {
+          "from": "a",
+          "name": "b",
+          "spec": "^1.0.0",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../b",
+      "target": Object {
+        "name": "b",
+        "parent": undefined,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-simple-virtual/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-simple-virtual/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+  },
+  "location": "",
+  "name": "workspaces-simple-virtual",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/load-virtual.js TAP workspaces load conflicting dep versions example > virtual tree with resolved conflicting dependencies 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-conflicting-versions-virtual/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": undefined,
+      },
+    },
+    "abbrev" => Node {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "abbrev",
+          "spec": "^1.1.1",
+          "type": "prod",
+        },
+        Edge {
+          "error": "INVALID",
+          "from": "packages/a",
+          "name": "abbrev",
+          "spec": "=1.0.4",
+          "type": "prod",
+        },
+        Edge {
+          "error": "INVALID",
+          "from": "packages/b",
+          "name": "abbrev",
+          "spec": "=1.1.0",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-conflicting-versions-virtual/packages/b",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../packages/b",
+      "target": Object {
+        "name": "b",
+        "parent": undefined,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-conflicting-versions-virtual/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "abbrev" => Edge {
+      "name": "abbrev",
+      "spec": "^1.1.1",
+      "to": "node_modules/abbrev",
+      "type": "prod",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-conflicting-versions-virtual/packages/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+  },
+  "location": "",
+  "name": "workspaces-conflicting-versions-virtual",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/load-virtual.js TAP workspaces load installed from registry on version not satisfied > virtual tree with deduped dep 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-version-unsatisfied-virtual/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": undefined,
+      },
+    },
+    "abbrev" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "abbrev",
+          "spec": "file:{CWD}/test/fixtures/workspaces-version-unsatisfied-virtual/packages/abbrev",
+          "type": "workspace",
+        },
+        Edge {
+          "error": "INVALID",
+          "from": "packages/a",
+          "name": "abbrev",
+          "spec": "=1.1.1",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "resolved": "file:../packages/abbrev",
+      "target": Object {
+        "name": "abbrev",
+        "parent": undefined,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-version-unsatisfied-virtual/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "abbrev" => Edge {
+      "name": "abbrev",
+      "spec": "file:{CWD}/test/fixtures/workspaces-version-unsatisfied-virtual/packages/abbrev",
+      "to": "node_modules/abbrev",
+      "type": "workspace",
+    },
+  },
+  "location": "",
+  "name": "workspaces-version-unsatisfied-virtual",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/load-virtual.js TAP workspaces load installed tree with ignored nested node_modules folders > virtual tree ignoring nested node_modules 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-ignore-nm-virtual/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": undefined,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-ignore-nm-virtual/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+  },
+  "location": "",
+  "name": "workspaces-ignore-nm-virtual",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/load-virtual.js TAP workspaces load installed workspace with transitive dependencies > virtual tree with transitive deps 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-transitive-deps-virtual/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": undefined,
+      },
+    },
+    "once" => Node {
+      "dev": true,
+      "edgesIn": Set {
+        Edge {
+          "from": "packages/a",
+          "name": "once",
+          "spec": "^1.4.0",
+          "type": "dev",
+        },
+      },
+      "edgesOut": Map {
+        "wrappy" => Edge {
+          "name": "wrappy",
+          "spec": "1",
+          "to": "node_modules/wrappy",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/once",
+      "name": "once",
+      "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
+    },
+    "wrappy" => Node {
+      "dev": true,
+      "edgesIn": Set {
+        Edge {
+          "from": "node_modules/once",
+          "name": "wrappy",
+          "spec": "1",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/wrappy",
+      "name": "wrappy",
+      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-transitive-deps-virtual/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+  },
+  "location": "",
+  "name": "workspaces-transitive-deps-virtual",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/load-virtual.js TAP workspaces load linked top level nested workspaces > virtual tree top level dep 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-top-level-link-virtual/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": undefined,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-top-level-link-virtual/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+  },
+  "location": "",
+  "name": "workspaces-top-level-link-virtual",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/load-virtual.js TAP workspaces load prefer linking nested workspaces > virtual tree linking to local workspaces 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-prefer-linking-virtual/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": undefined,
+      },
+    },
+    "abbrev" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "abbrev",
+          "spec": "file:{CWD}/test/fixtures/workspaces-prefer-linking-virtual/packages/abbrev",
+          "type": "workspace",
+        },
+        Edge {
+          "from": "packages/a",
+          "name": "abbrev",
+          "spec": "*",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "resolved": "file:../packages/abbrev",
+      "target": Object {
+        "name": "abbrev",
+        "parent": undefined,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-prefer-linking-virtual/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "abbrev" => Edge {
+      "name": "abbrev",
+      "spec": "file:{CWD}/test/fixtures/workspaces-prefer-linking-virtual/packages/abbrev",
+      "to": "node_modules/abbrev",
+      "type": "workspace",
+    },
+  },
+  "location": "",
+  "name": "workspaces-prefer-linking-virtual",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/load-virtual.js TAP workspaces load shared dependencies example > virtual tree with shared dependencies 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps-virtual/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": undefined,
+      },
+    },
+    "abbrev" => Node {
+      "edgesIn": Set {
+        Edge {
+          "from": "packages/a",
+          "name": "abbrev",
+          "spec": "^1.1.1",
+          "type": "prod",
+        },
+        Edge {
+          "from": "packages/b",
+          "name": "abbrev",
+          "spec": "^1.1.1",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps-virtual/packages/b",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../packages/b",
+      "target": Object {
+        "name": "b",
+        "parent": undefined,
+      },
+    },
+    "c" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "c",
+          "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps-virtual/packages/c",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/c",
+      "name": "c",
+      "resolved": "file:../packages/c",
+      "target": Object {
+        "name": "c",
+        "parent": undefined,
+      },
+    },
+    "uuid" => Node {
+      "edgesIn": Set {
+        Edge {
+          "from": "packages/c",
+          "name": "uuid",
+          "spec": "=3.3.3",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/uuid",
+      "name": "uuid",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.3.3.tgz",
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps-virtual/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps-virtual/packages/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+    "c" => Edge {
+      "name": "c",
+      "spec": "file:{CWD}/test/fixtures/workspaces-shared-deps-virtual/packages/c",
+      "to": "node_modules/c",
+      "type": "workspace",
+    },
+  },
+  "location": "",
+  "name": "workspaces-shared-deps-virtual",
+  "resolved": null,
+}
+`
diff --git a/tap-snapshots/test-arborist-reify.js-TAP.test.js b/tap-snapshots/test-arborist-reify.js-TAP.test.js
index c564bb5b5..2fe428037 100644
--- a/tap-snapshots/test-arborist-reify.js-TAP.test.js
+++ b/tap-snapshots/test-arborist-reify.js-TAP.test.js
@@ -33323,3 +33323,201 @@ Node {
   "resolved": null,
 }
 `
+
+exports[`test/arborist/reify.js TAP workspaces reify simple-workspaces > should reify simple workspaces 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/arborist/reify-workspaces-reify-simple-workspaces/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/arborist/reify-workspaces-reify-simple-workspaces/b",
+          "type": "workspace",
+        },
+        Edge {
+          "from": "a",
+          "name": "b",
+          "spec": "^1.0.0",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../b",
+      "target": Object {
+        "name": "b",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/arborist/reify-workspaces-reify-simple-workspaces/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/arborist/reify-workspaces-reify-simple-workspaces/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "edgesOut": Map {
+        "b" => Edge {
+          "name": "b",
+          "spec": "^1.0.0",
+          "to": "node_modules/b",
+          "type": "prod",
+        },
+      },
+      "location": "a",
+      "name": "a",
+      "resolved": null,
+    },
+    Node {
+      "location": "b",
+      "name": "b",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "reify-workspaces-reify-simple-workspaces",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/reify.js TAP workspaces reify workspaces bin files > expect resolving Promise 1`] = `
+Node {
+  "children": Map {
+    "a" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/arborist/reify-workspaces-reify-workspaces-bin-files/packages/a",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/a",
+      "name": "a",
+      "resolved": "file:../packages/a",
+      "target": Object {
+        "name": "a",
+        "parent": null,
+      },
+    },
+    "b" => Link {
+      "edgesIn": Set {
+        Edge {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/arborist/reify-workspaces-reify-workspaces-bin-files/packages/b",
+          "type": "workspace",
+        },
+      },
+      "location": "node_modules/b",
+      "name": "b",
+      "resolved": "file:../packages/b",
+      "target": Object {
+        "name": "b",
+        "parent": null,
+      },
+    },
+  },
+  "edgesOut": Map {
+    "a" => Edge {
+      "name": "a",
+      "spec": "file:{CWD}/test/arborist/reify-workspaces-reify-workspaces-bin-files/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "b" => Edge {
+      "name": "b",
+      "spec": "file:{CWD}/test/arborist/reify-workspaces-reify-workspaces-bin-files/packages/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+  },
+  "fsChildren": Set {
+    Node {
+      "location": "packages/a",
+      "name": "a",
+      "resolved": null,
+    },
+    Node {
+      "location": "packages/b",
+      "name": "b",
+      "resolved": null,
+    },
+  },
+  "location": "",
+  "name": "reify-workspaces-reify-workspaces-bin-files",
+  "resolved": null,
+}
+`
+
+exports[`test/arborist/reify.js TAP workspaces reify workspaces lockfile > should lock workspaces config 1`] = `
+Object {
+  "dependencies": Object {
+    "a": Object {
+      "version": "file:a",
+    },
+    "b": Object {
+      "version": "file:b",
+    },
+  },
+  "lockfileVersion": 2,
+  "name": "workspace-simple",
+  "packages": Object {
+    "": Object {
+      "name": "workspace-simple",
+      "workspaces": Array [
+        "a",
+        "b",
+      ],
+    },
+    "a": Object {
+      "dependencies": Object {
+        "b": "^1.0.0",
+      },
+      "name": "a",
+      "version": "1.0.0",
+    },
+    "b": Object {
+      "name": "b",
+      "version": "1.0.0",
+    },
+    "node_modules/a": Object {
+      "link": true,
+      "resolved": "a",
+    },
+    "node_modules/b": Object {
+      "link": true,
+      "resolved": "b",
+    },
+  },
+  "requires": true,
+}
+`
diff --git a/tap-snapshots/test-node.js-TAP.test.js b/tap-snapshots/test-node.js-TAP.test.js
index 810e2e99a..7de4940de 100644
--- a/tap-snapshots/test-node.js-TAP.test.js
+++ b/tap-snapshots/test-node.js-TAP.test.js
@@ -31,6 +31,35 @@ Node {
 }
 `
 
+exports[`test/node.js TAP set workspaces > should setup edges out for each workspace 1`] = `
+Node {
+  "children": Map {},
+  "dev": true,
+  "devOptional": true,
+  "edgesIn": Set {},
+  "edgesOut": Map {
+    "foo" => Edge {},
+    "bar" => Edge {},
+  },
+  "errors": Array [],
+  "extraneous": true,
+  "fsChildren": Set {},
+  "hasShrinkwrap": false,
+  "integrity": null,
+  "inventory": Inventory {},
+  "legacyPeerDeps": false,
+  "linksIn": Set {},
+  "location": "",
+  "meta": undefined,
+  "name": "workspaces_root",
+  "optional": true,
+  "path": "/home/user/projects/workspaces_root",
+  "peer": true,
+  "realpath": "/home/user/projects/workspaces_root",
+  "resolved": null,
+}
+`
+
 exports[`test/node.js TAP testing with dep tree with meta > add new meta under prod 1`] = `
 Node {
   "children": Map {
diff --git a/test/arborist/build-ideal-tree.js b/test/arborist/build-ideal-tree.js
index 743e8b093..14a550752 100644
--- a/test/arborist/build-ideal-tree.js
+++ b/test/arborist/build-ideal-tree.js
@@ -1015,3 +1015,64 @@ t.test('no fix available, linked top package', async t => {
     "'cd ./mkdirp-unfixable' and run 'npm audit' for details."
   ]])
 })
+
+t.test('workspaces', t => {
+  t.test('should install a simple example', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-simple')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should install a simple scoped pkg example', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-scoped-pkg')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should not work with duplicate names', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-duplicate')
+    return t.rejects(printIdeal(path), { code: 'EDUPLICATEWORKSPACE' }, 'throws EDUPLICATEWORKSPACE error')
+  })
+
+  t.test('should install shared dependencies into root folder', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-shared-deps')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should install conflicting dep versions', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-conflicting-versions')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should prefer linking nested workspaces', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-prefer-linking')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should install from registry on version not satisfied', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-version-unsatisfied')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should link top level nested workspaces', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-top-level-link')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should install workspace transitive dependencies', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-transitive-deps')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should ignore nested node_modules folders', t => {
+    // packages/a/node_modules/nested-workspaces should not be installed
+    const path = resolve(__dirname, '../fixtures/workspaces-ignore-nm')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.test('should work with files spec', t => {
+    const path = resolve(__dirname, '../fixtures/workspaces-with-files-spec')
+    return t.resolveMatchSnapshot(printIdeal(path))
+  })
+
+  t.end()
+})
+
diff --git a/test/arborist/load-virtual.js b/test/arborist/load-virtual.js
index d870090d2..4abff3b82 100644
--- a/test/arborist/load-virtual.js
+++ b/test/arborist/load-virtual.js
@@ -146,3 +146,56 @@ t.test('load a tree with a bunch of bundles', t =>
 t.test('load a tree with an empty dep set and a lockfile', t =>
   loadVirtual(emptyFixture).then(tree =>
     t.matchSnapshot(printTree(tree), 'virtual tree with no deps')))
+
+t.test('workspaces', t => {
+  t.test('load a simple example', t =>
+    loadVirtual(
+      resolve(__dirname, '../fixtures/workspaces-simple-virtual')
+    ).then(tree =>
+      t.matchSnapshot(printTree(tree), 'virtual tree with multiple bundles')))
+
+  t.test('load shared dependencies example', t =>
+    loadVirtual(
+      resolve(__dirname, '../fixtures/workspaces-shared-deps-virtual')
+    ).then(tree =>
+      t.matchSnapshot(printTree(tree), 'virtual tree with shared dependencies')))
+
+  t.test('load conflicting dep versions example', t => 
+    loadVirtual(
+      resolve(__dirname, '../fixtures/workspaces-conflicting-versions-virtual')
+    ).then(tree =>
+      t.matchSnapshot(printTree(tree), 'virtual tree with resolved conflicting dependencies')))
+
+  t.test('load prefer linking nested workspaces', t => 
+    loadVirtual(
+      resolve(__dirname, '../fixtures/workspaces-prefer-linking-virtual')
+    ).then(tree =>
+      t.matchSnapshot(printTree(tree), 'virtual tree linking to local workspaces')))
+
+  t.test('load installed from registry on version not satisfied', t =>
+    loadVirtual(
+      resolve(__dirname, '../fixtures/workspaces-version-unsatisfied-virtual')
+    ).then(tree =>
+      t.matchSnapshot(printTree(tree), 'virtual tree with deduped dep')))
+
+
+  t.test('load linked top level nested workspaces', t =>
+    loadVirtual(
+      resolve(__dirname, '../fixtures/workspaces-top-level-link-virtual')
+    ).then(tree =>
+      t.matchSnapshot(printTree(tree), 'virtual tree top level dep')))
+
+  t.test('load installed workspace with transitive dependencies', t =>
+    loadVirtual(
+      resolve(__dirname, '../fixtures/workspaces-transitive-deps-virtual')
+    ).then(tree =>
+      t.matchSnapshot(printTree(tree), 'virtual tree with transitive deps')))
+
+  t.test('load installed tree with ignored nested node_modules folders', t =>
+    loadVirtual(
+      resolve(__dirname, '../fixtures/workspaces-ignore-nm-virtual')
+    ).then(tree =>
+      t.matchSnapshot(printTree(tree), 'virtual tree ignoring nested node_modules')))
+
+  t.end()
+})
diff --git a/test/arborist/reify.js b/test/arborist/reify.js
index 3494c8218..3b92cd8e9 100644
--- a/test/arborist/reify.js
+++ b/test/arborist/reify.js
@@ -886,3 +886,38 @@ t.test('global', t => {
 
   t.end()
 })
+
+t.test('workspaces', t => {
+  t.test('reify simple-workspaces', t =>
+    t.resolveMatchSnapshot(printReified(fixture(t, 'workspaces-simple')), 'should reify simple workspaces'))
+
+  t.test('reify workspaces lockfile', t => {
+    const path = fixture(t, 'workspaces-simple')
+    reify(path).then(() => {
+      t.matchSnapshot(require(path + '/package-lock.json'), 'should lock workspaces config')
+      t.end()
+    })
+  })
+
+  t.test('reify workspaces bin files', t => {
+    const path = fixture(t, 'workspaces-link-bin')
+
+    const bins = [
+      resolve(path, 'node_modules/.bin/a'),
+      resolve(path, 'node_modules/.bin/b'),
+    ]
+
+    const checkBin = () => {
+      for (const bin of bins)
+        if (process.platform === 'win32')
+          t.ok(fs.statSync(bin + '.cmd').isFile(), 'created shim')
+        else
+          t.ok(fs.lstatSync(bin).isSymbolicLink(), 'created symlink')
+    }
+
+    return t.resolveMatchSnapshot(printReified(path, {}))
+      .then(checkBin)
+  })
+
+  t.end()
+})
diff --git a/test/edge.js b/test/edge.js
index 3a23c6216..10fdfb925 100644
--- a/test/edge.js
+++ b/test/edge.js
@@ -278,3 +278,9 @@ t.throws(() => new Edge({
   name: 'foo',
   spec: '',
 }), new TypeError('must provide "from" node'))
+
+t.throws(() => new Edge({
+  type: 'workspace',
+  name: 'foo',
+  spec: '*',
+}), new TypeError('workspace edges must be a symlink'))
diff --git a/test/fixtures/reify-cases/workspaces-link-bin.js b/test/fixtures/reify-cases/workspaces-link-bin.js
new file mode 100644
index 000000000..52a8158e8
--- /dev/null
+++ b/test/fixtures/reify-cases/workspaces-link-bin.js
@@ -0,0 +1,38 @@
+// generated from test/fixtures/workspaces-link-bin
+module.exports = t => ({
+  "foo.js": "",
+  "package.json": JSON.stringify({
+    "name": "workspace-duplicate",
+    "bin": "foo.js",
+    "workspaces": [
+      "packages/*"
+    ],
+    "dependencies": {
+      "a": "*"
+    }
+  }),
+  "packages": {
+    "a": {
+      "file.js": "",
+      "package.json": JSON.stringify({
+        "name": "a",
+        "version": "1.0.0",
+        "files": [
+          "file.js"
+        ],
+        "bin": "file.js"
+      })
+    },
+    "b": {
+      "file.js": "",
+      "package.json": JSON.stringify({
+        "name": "b",
+        "version": "1.0.0",
+        "files": [
+          "file.js"
+        ],
+        "bin": "file.js"
+      })
+    }
+  }
+})
diff --git a/test/fixtures/reify-cases/workspaces-simple.js b/test/fixtures/reify-cases/workspaces-simple.js
new file mode 100644
index 000000000..bc0f0e256
--- /dev/null
+++ b/test/fixtures/reify-cases/workspaces-simple.js
@@ -0,0 +1,25 @@
+// generated from test/fixtures/workspaces-simple
+module.exports = t => ({
+  "a": {
+    "package.json": JSON.stringify({
+      "name": "a",
+      "version": "1.0.0",
+      "dependencies": {
+        "b": "^1.0.0"
+      }
+    })
+  },
+  "b": {
+    "package.json": JSON.stringify({
+      "name": "b",
+      "version": "1.0.0"
+    })
+  },
+  "package.json": JSON.stringify({
+    "name": "workspace-simple",
+    "workspaces": [
+      "a",
+      "b"
+    ]
+  })
+})
diff --git a/test/fixtures/workspaces-conflicting-versions-virtual/package-lock.json b/test/fixtures/workspaces-conflicting-versions-virtual/package-lock.json
new file mode 100644
index 000000000..03986615a
--- /dev/null
+++ b/test/fixtures/workspaces-conflicting-versions-virtual/package-lock.json
@@ -0,0 +1,91 @@
+{
+  "name": "workspaces-conflicting-deps",
+  "version": "1.0.0",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "workspaces-conflicting-deps",
+      "version": "1.0.0",
+      "dependencies": {
+        "abbrev": "^1.1.1"
+      },
+      "workspaces": {
+        "packages": [
+          "packages/*"
+        ]
+      }
+    },
+    "node_modules/a": {
+      "resolved": "packages/a",
+      "link": true
+    },
+    "node_modules/abbrev": {
+      "name": "abbrev",
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+      "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
+    },
+    "node_modules/b": {
+      "resolved": "packages/b",
+      "link": true
+    },
+    "packages/a": {
+      "name": "a",
+      "version": "1.0.0",
+      "dependencies": {
+        "abbrev": "=1.0.4"
+      }
+    },
+    "packages/a/node_modules/abbrev": {
+      "name": "abbrev",
+      "version": "1.0.4",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.0.4.tgz",
+      "integrity": "sha1-vVWuXkE7oXIu5Mq6H26hBBSlns0="
+    },
+    "packages/b": {
+      "name": "b",
+      "version": "1.0.0",
+      "dependencies": {
+        "abbrev": "=1.1.0"
+      }
+    },
+    "packages/b/node_modules/abbrev": {
+      "name": "abbrev",
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.0.tgz",
+      "integrity": "sha1-0FVMIlZjbi9W58LlrRg/hZQo2B8="
+    }
+  },
+  "dependencies": {
+    "a": {
+      "version": "file:packages/a"
+    },
+    "abbrev": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+      "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
+    },
+    "b": {
+      "version": "file:packages/b"
+    },
+    "packages/a": {
+      "dependencies": {
+        "abbrev": {
+          "version": "1.0.4",
+          "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.0.4.tgz",
+          "integrity": "sha1-vVWuXkE7oXIu5Mq6H26hBBSlns0="
+        }
+      }
+    },
+    "packages/b": {
+      "dependencies": {
+        "abbrev": {
+          "version": "1.1.0",
+          "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.0.tgz",
+          "integrity": "sha1-0FVMIlZjbi9W58LlrRg/hZQo2B8="
+        }
+      }
+    }
+  }
+}
diff --git a/test/fixtures/workspaces-conflicting-versions-virtual/package.json b/test/fixtures/workspaces-conflicting-versions-virtual/package.json
new file mode 100644
index 000000000..651d43b5b
--- /dev/null
+++ b/test/fixtures/workspaces-conflicting-versions-virtual/package.json
@@ -0,0 +1,10 @@
+{
+  "name": "workspaces-conflicting-deps",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ],
+  "dependencies": {
+    "abbrev": "^1.1.1"
+  }
+}
diff --git a/test/fixtures/workspaces-conflicting-versions/package.json b/test/fixtures/workspaces-conflicting-versions/package.json
new file mode 100644
index 000000000..447380094
--- /dev/null
+++ b/test/fixtures/workspaces-conflicting-versions/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "workspaces-conflicting-deps",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ],
+  "dependencies": {
+    "abbrev": "^1.1.1"
+  }
+}
+
diff --git a/test/fixtures/workspaces-conflicting-versions/packages/a/package.json b/test/fixtures/workspaces-conflicting-versions/packages/a/package.json
new file mode 100644
index 000000000..f9904d309
--- /dev/null
+++ b/test/fixtures/workspaces-conflicting-versions/packages/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "abbrev": "=1.0.4"
+  }
+}
diff --git a/test/fixtures/workspaces-conflicting-versions/packages/b/package.json b/test/fixtures/workspaces-conflicting-versions/packages/b/package.json
new file mode 100644
index 000000000..a3440f267
--- /dev/null
+++ b/test/fixtures/workspaces-conflicting-versions/packages/b/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "b",
+  "version": "1.0.0",
+  "dependencies": {
+    "abbrev": "=1.1.0"
+  }
+}
diff --git a/test/fixtures/workspaces-duplicate/package.json b/test/fixtures/workspaces-duplicate/package.json
new file mode 100644
index 000000000..985971c00
--- /dev/null
+++ b/test/fixtures/workspaces-duplicate/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "workspace-duplicate",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-duplicate/packages/a/package.json b/test/fixtures/workspaces-duplicate/packages/a/package.json
new file mode 100644
index 000000000..9113c2528
--- /dev/null
+++ b/test/fixtures/workspaces-duplicate/packages/a/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "a",
+  "version": "1.0.0"
+}
diff --git a/test/fixtures/workspaces-duplicate/packages/b/package.json b/test/fixtures/workspaces-duplicate/packages/b/package.json
new file mode 100644
index 000000000..9113c2528
--- /dev/null
+++ b/test/fixtures/workspaces-duplicate/packages/b/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "a",
+  "version": "1.0.0"
+}
diff --git a/test/fixtures/workspaces-ignore-nm-virtual/package-lock.json b/test/fixtures/workspaces-ignore-nm-virtual/package-lock.json
new file mode 100644
index 000000000..c56b75472
--- /dev/null
+++ b/test/fixtures/workspaces-ignore-nm-virtual/package-lock.json
@@ -0,0 +1,28 @@
+{
+  "name": "workspace-ignore-nm",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "workspace-ignore-nm",
+      "workspaces": {
+        "packages": [
+          "packages/**"
+        ]
+      }
+    },
+    "node_modules/a": {
+      "resolved": "packages/a",
+      "link": true
+    },
+    "packages/a": {
+      "name": "a",
+      "version": "1.0.0"
+    }
+  },
+  "dependencies": {
+    "a": {
+      "version": "file:packages/a"
+    }
+  }
+}
diff --git a/test/fixtures/workspaces-ignore-nm-virtual/package.json b/test/fixtures/workspaces-ignore-nm-virtual/package.json
new file mode 100644
index 000000000..5d63a1514
--- /dev/null
+++ b/test/fixtures/workspaces-ignore-nm-virtual/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "workspace-ignore-nm",
+  "workspaces": [
+    "packages/**"
+  ]
+}
diff --git a/test/fixtures/workspaces-ignore-nm/package.json b/test/fixtures/workspaces-ignore-nm/package.json
new file mode 100644
index 000000000..be7d871a6
--- /dev/null
+++ b/test/fixtures/workspaces-ignore-nm/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspace-ignore-nm",
+  "workspaces": [
+    "packages/**"
+  ]
+}
+
diff --git a/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/c/package.json b/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/c/package.json
new file mode 100644
index 000000000..abd338493
--- /dev/null
+++ b/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/c/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "c",
+  "version": "1.0.0"
+}
diff --git a/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/nested-workspace/d/package.json b/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/nested-workspace/d/package.json
new file mode 100644
index 000000000..ebbfbae0d
--- /dev/null
+++ b/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/nested-workspace/d/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "d",
+  "version": "1.0.0",
+  "dependencies": {
+    "abbrev": "^1.1.1"
+  }
+}
diff --git a/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/nested-workspace/package.json b/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/nested-workspace/package.json
new file mode 100644
index 000000000..b156dca8f
--- /dev/null
+++ b/test/fixtures/workspaces-ignore-nm/packages/a/node_modules/nested-workspace/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "nested-workspace",
+  "version": "1.0.0",
+  "workspaces": [
+    "./d"
+  ]
+}
diff --git a/test/fixtures/workspaces-ignore-nm/packages/a/package.json b/test/fixtures/workspaces-ignore-nm/packages/a/package.json
new file mode 100644
index 000000000..8fe98232f
--- /dev/null
+++ b/test/fixtures/workspaces-ignore-nm/packages/a/package.json
@@ -0,0 +1,5 @@
+{
+  "name": "a",
+  "version": "1.0.0"
+}
+
diff --git a/test/fixtures/workspaces-link-bin/foo.js b/test/fixtures/workspaces-link-bin/foo.js
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/fixtures/workspaces-link-bin/package.json b/test/fixtures/workspaces-link-bin/package.json
new file mode 100644
index 000000000..d3560fc73
--- /dev/null
+++ b/test/fixtures/workspaces-link-bin/package.json
@@ -0,0 +1,10 @@
+{
+  "name": "workspace-duplicate",
+  "bin": "foo.js",
+  "workspaces": [
+    "packages/*"
+  ],
+  "dependencies": {
+    "a": "*"
+  }
+}
diff --git a/test/fixtures/workspaces-link-bin/packages/a/file.js b/test/fixtures/workspaces-link-bin/packages/a/file.js
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/fixtures/workspaces-link-bin/packages/a/package.json b/test/fixtures/workspaces-link-bin/packages/a/package.json
new file mode 100644
index 000000000..c8fa2d1d7
--- /dev/null
+++ b/test/fixtures/workspaces-link-bin/packages/a/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "files": ["file.js"],
+  "bin": "file.js"
+}
diff --git a/test/fixtures/workspaces-link-bin/packages/b/file.js b/test/fixtures/workspaces-link-bin/packages/b/file.js
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/fixtures/workspaces-link-bin/packages/b/package.json b/test/fixtures/workspaces-link-bin/packages/b/package.json
new file mode 100644
index 000000000..52a65b6fa
--- /dev/null
+++ b/test/fixtures/workspaces-link-bin/packages/b/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "b",
+  "version": "1.0.0",
+  "files": ["file.js"],
+  "bin": "file.js"
+}
diff --git a/test/fixtures/workspaces-prefer-linking-virtual/package-lock.json b/test/fixtures/workspaces-prefer-linking-virtual/package-lock.json
new file mode 100644
index 000000000..53b4e2d51
--- /dev/null
+++ b/test/fixtures/workspaces-prefer-linking-virtual/package-lock.json
@@ -0,0 +1,42 @@
+{
+  "name": "workspaces-prefer-linking",
+  "version": "1.0.0",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "workspaces-prefer-linking",
+      "version": "1.0.0",
+      "workspaces": [
+        "packages/*"
+      ]
+    },
+    "node_modules/a": {
+      "resolved": "packages/a",
+      "link": true
+    },
+    "node_modules/abbrev": {
+      "resolved": "packages/abbrev",
+      "link": true
+    },
+    "packages/a": {
+      "name": "a",
+      "version": "1.0.0",
+      "dependencies": {
+        "abbrev": "*"
+      }
+    },
+    "packages/abbrev": {
+      "name": "abbrev",
+      "version": "2.0.0"
+    }
+  },
+  "dependencies": {
+    "a": {
+      "version": "file:packages/a"
+    },
+    "abbrev": {
+      "version": "file:packages/abbrev"
+    }
+  }
+}
diff --git a/test/fixtures/workspaces-prefer-linking-virtual/package.json b/test/fixtures/workspaces-prefer-linking-virtual/package.json
new file mode 100644
index 000000000..6a15efe53
--- /dev/null
+++ b/test/fixtures/workspaces-prefer-linking-virtual/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspaces-prefer-linking",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-prefer-linking/package.json b/test/fixtures/workspaces-prefer-linking/package.json
new file mode 100644
index 000000000..6a15efe53
--- /dev/null
+++ b/test/fixtures/workspaces-prefer-linking/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspaces-prefer-linking",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-prefer-linking/packages/a/package.json b/test/fixtures/workspaces-prefer-linking/packages/a/package.json
new file mode 100644
index 000000000..7d15acabe
--- /dev/null
+++ b/test/fixtures/workspaces-prefer-linking/packages/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "abbrev": "*"
+  }
+}
diff --git a/test/fixtures/workspaces-prefer-linking/packages/abbrev/package.json b/test/fixtures/workspaces-prefer-linking/packages/abbrev/package.json
new file mode 100644
index 000000000..36b0d44ae
--- /dev/null
+++ b/test/fixtures/workspaces-prefer-linking/packages/abbrev/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "abbrev",
+  "version": "2.0.0",
+  "description": "Like ruby's abbrev module, but in js",
+  "author": "Isaac Z. Schlueter <i@izs.me>"
+}
diff --git a/test/fixtures/workspaces-scoped-pkg/package.json b/test/fixtures/workspaces-scoped-pkg/package.json
new file mode 100644
index 000000000..695f4a49e
--- /dev/null
+++ b/test/fixtures/workspaces-scoped-pkg/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "workspace-simple",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-scoped-pkg/packages/a/package.json b/test/fixtures/workspaces-scoped-pkg/packages/a/package.json
new file mode 100644
index 000000000..cc566d017
--- /dev/null
+++ b/test/fixtures/workspaces-scoped-pkg/packages/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "@ruyadorno/scoped-a",
+  "version": "1.0.0",
+  "dependencies": {
+    "@ruyadorno/scoped-b": "^1.0.0"
+  }
+}
diff --git a/test/fixtures/workspaces-scoped-pkg/packages/b/package.json b/test/fixtures/workspaces-scoped-pkg/packages/b/package.json
new file mode 100644
index 000000000..3b48f952e
--- /dev/null
+++ b/test/fixtures/workspaces-scoped-pkg/packages/b/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "@ruyadorno/scoped-b",
+  "version": "1.0.0"
+}
diff --git a/test/fixtures/workspaces-shared-deps-virtual/package-lock.json b/test/fixtures/workspaces-shared-deps-virtual/package-lock.json
new file mode 100644
index 000000000..3d77c2f42
--- /dev/null
+++ b/test/fixtures/workspaces-shared-deps-virtual/package-lock.json
@@ -0,0 +1,86 @@
+{
+  "name": "workspaces-shared-deps",
+  "version": "1.0.0",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "workspaces-shared-deps",
+      "version": "1.0.0",
+      "workspaces": {
+        "packages": [
+          "packages/*"
+        ]
+      }
+    },
+    "node_modules/a": {
+      "resolved": "packages/a",
+      "link": true
+    },
+    "node_modules/abbrev": {
+      "name": "abbrev",
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+      "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
+    },
+    "node_modules/b": {
+      "resolved": "packages/b",
+      "link": true
+    },
+    "node_modules/c": {
+      "resolved": "packages/c",
+      "link": true
+    },
+    "node_modules/uuid": {
+      "name": "uuid",
+      "version": "3.3.3",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.3.3.tgz",
+      "integrity": "sha512-pW0No1RGHgzlpHJO1nsVrHKpOEIxkGg1xB+v0ZmdNH5OAeAwzAVrCnI2/6Mtx+Uys6iaylxa+D3g4j63IKKjSQ==",
+      "bin": {
+        "uuid": "bin/uuid"
+      }
+    },
+    "packages/a": {
+      "name": "a",
+      "version": "1.0.0",
+      "dependencies": {
+        "abbrev": "^1.1.1"
+      }
+    },
+    "packages/b": {
+      "name": "b",
+      "version": "1.0.0",
+      "dependencies": {
+        "abbrev": "^1.1.1"
+      }
+    },
+    "packages/c": {
+      "name": "c",
+      "version": "1.0.0",
+      "dependencies": {
+        "uuid": "=3.3.3"
+      }
+    }
+  },
+  "dependencies": {
+    "a": {
+      "version": "file:packages/a"
+    },
+    "abbrev": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+      "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
+    },
+    "b": {
+      "version": "file:packages/b"
+    },
+    "c": {
+      "version": "file:packages/c"
+    },
+    "uuid": {
+      "version": "3.3.3",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.3.3.tgz",
+      "integrity": "sha512-pW0No1RGHgzlpHJO1nsVrHKpOEIxkGg1xB+v0ZmdNH5OAeAwzAVrCnI2/6Mtx+Uys6iaylxa+D3g4j63IKKjSQ=="
+    }
+  }
+}
diff --git a/test/fixtures/workspaces-shared-deps-virtual/package.json b/test/fixtures/workspaces-shared-deps-virtual/package.json
new file mode 100644
index 000000000..4c634a1e0
--- /dev/null
+++ b/test/fixtures/workspaces-shared-deps-virtual/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspaces-shared-deps",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-shared-deps/package.json b/test/fixtures/workspaces-shared-deps/package.json
new file mode 100644
index 000000000..4c634a1e0
--- /dev/null
+++ b/test/fixtures/workspaces-shared-deps/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspaces-shared-deps",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-shared-deps/packages/a/package.json b/test/fixtures/workspaces-shared-deps/packages/a/package.json
new file mode 100644
index 000000000..7a2d0d4df
--- /dev/null
+++ b/test/fixtures/workspaces-shared-deps/packages/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "abbrev": "^1.1.1"
+  }
+}
diff --git a/test/fixtures/workspaces-shared-deps/packages/b/package.json b/test/fixtures/workspaces-shared-deps/packages/b/package.json
new file mode 100644
index 000000000..4c9154387
--- /dev/null
+++ b/test/fixtures/workspaces-shared-deps/packages/b/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "b",
+  "version": "1.0.0",
+  "dependencies": {
+    "abbrev": "^1.1.1"
+  }
+}
diff --git a/test/fixtures/workspaces-shared-deps/packages/c/package.json b/test/fixtures/workspaces-shared-deps/packages/c/package.json
new file mode 100644
index 000000000..7f017b6a5
--- /dev/null
+++ b/test/fixtures/workspaces-shared-deps/packages/c/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "c",
+  "version": "1.0.0",
+  "dependencies": {
+    "uuid": "=3.3.3"
+  }
+}
diff --git a/test/fixtures/workspaces-simple-virtual/a/package.json b/test/fixtures/workspaces-simple-virtual/a/package.json
new file mode 100644
index 000000000..0dd22e08b
--- /dev/null
+++ b/test/fixtures/workspaces-simple-virtual/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "b": "^1.0.0"
+  }
+}
diff --git a/test/fixtures/workspaces-simple-virtual/b/package.json b/test/fixtures/workspaces-simple-virtual/b/package.json
new file mode 100644
index 000000000..c2d84cc12
--- /dev/null
+++ b/test/fixtures/workspaces-simple-virtual/b/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "b",
+  "version": "1.0.0"
+}
diff --git a/test/fixtures/workspaces-simple-virtual/package-lock.json b/test/fixtures/workspaces-simple-virtual/package-lock.json
new file mode 100644
index 000000000..dc8021e80
--- /dev/null
+++ b/test/fixtures/workspaces-simple-virtual/package-lock.json
@@ -0,0 +1,43 @@
+{
+  "name": "workspace-simple",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "workspace-simple",
+      "workspaces": {
+        "packages": [
+          "a",
+          "b"
+        ]
+      }
+    },
+    "a": {
+      "name": "a",
+      "version": "1.0.0",
+      "dependencies": {
+        "b": "^1.0.0"
+      }
+    },
+    "b": {
+      "name": "b",
+      "version": "1.0.0"
+    },
+    "node_modules/a": {
+      "resolved": "a",
+      "link": true
+    },
+    "node_modules/b": {
+      "resolved": "b",
+      "link": true
+    }
+  },
+  "dependencies": {
+    "a": {
+      "version": "file:a"
+    },
+    "b": {
+      "version": "file:b"
+    }
+  }
+}
diff --git a/test/fixtures/workspaces-simple-virtual/package.json b/test/fixtures/workspaces-simple-virtual/package.json
new file mode 100644
index 000000000..6fb34c3f2
--- /dev/null
+++ b/test/fixtures/workspaces-simple-virtual/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspace-simple",
+  "workspaces": [
+    "a",
+    "b"
+  ]
+}
diff --git a/test/fixtures/workspaces-simple/a/package.json b/test/fixtures/workspaces-simple/a/package.json
new file mode 100644
index 000000000..0dd22e08b
--- /dev/null
+++ b/test/fixtures/workspaces-simple/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "b": "^1.0.0"
+  }
+}
diff --git a/test/fixtures/workspaces-simple/b/package.json b/test/fixtures/workspaces-simple/b/package.json
new file mode 100644
index 000000000..c2d84cc12
--- /dev/null
+++ b/test/fixtures/workspaces-simple/b/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "b",
+  "version": "1.0.0"
+}
diff --git a/test/fixtures/workspaces-simple/package.json b/test/fixtures/workspaces-simple/package.json
new file mode 100644
index 000000000..6fb34c3f2
--- /dev/null
+++ b/test/fixtures/workspaces-simple/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspace-simple",
+  "workspaces": [
+    "a",
+    "b"
+  ]
+}
diff --git a/test/fixtures/workspaces-top-level-link-virtual/package-lock.json b/test/fixtures/workspaces-top-level-link-virtual/package-lock.json
new file mode 100644
index 000000000..1114c807c
--- /dev/null
+++ b/test/fixtures/workspaces-top-level-link-virtual/package-lock.json
@@ -0,0 +1,33 @@
+{
+  "name": "workspaces-top-level-link",
+  "version": "1.0.0",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "workspaces-top-level-link",
+      "version": "1.0.0",
+      "dependencies": {
+        "a": "^1.0.0"
+      },
+      "workspaces": {
+        "packages": [
+          "packages/*"
+        ]
+      }
+    },
+    "node_modules/a": {
+      "resolved": "packages/a",
+      "link": true
+    },
+    "packages/a": {
+      "name": "a",
+      "version": "1.0.0"
+    }
+  },
+  "dependencies": {
+    "a": {
+      "version": "file:packages/a"
+    }
+  }
+}
diff --git a/test/fixtures/workspaces-top-level-link-virtual/package.json b/test/fixtures/workspaces-top-level-link-virtual/package.json
new file mode 100644
index 000000000..2d2564945
--- /dev/null
+++ b/test/fixtures/workspaces-top-level-link-virtual/package.json
@@ -0,0 +1,10 @@
+{
+  "name": "workspaces-top-level-link",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ],
+  "dependencies": {
+    "a": "^1.0.0"
+  }
+}
diff --git a/test/fixtures/workspaces-top-level-link/package.json b/test/fixtures/workspaces-top-level-link/package.json
new file mode 100644
index 000000000..aaa2088e4
--- /dev/null
+++ b/test/fixtures/workspaces-top-level-link/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "workspaces-top-level-link",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ],
+  "dependencies": {
+    "a": "^1.0.0"
+  }
+}
+
diff --git a/test/fixtures/workspaces-top-level-link/packages/a/package.json b/test/fixtures/workspaces-top-level-link/packages/a/package.json
new file mode 100644
index 000000000..8fe98232f
--- /dev/null
+++ b/test/fixtures/workspaces-top-level-link/packages/a/package.json
@@ -0,0 +1,5 @@
+{
+  "name": "a",
+  "version": "1.0.0"
+}
+
diff --git a/test/fixtures/workspaces-transitive-deps-virtual/package-lock.json b/test/fixtures/workspaces-transitive-deps-virtual/package-lock.json
new file mode 100644
index 000000000..8e939d83e
--- /dev/null
+++ b/test/fixtures/workspaces-transitive-deps-virtual/package-lock.json
@@ -0,0 +1,63 @@
+{
+  "name": "workspaces-transitive-deps",
+  "version": "1.0.0",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "workspaces-transitive-deps",
+      "version": "1.0.0",
+      "workspaces": [
+        "packages/*"
+      ]
+    },
+    "node_modules/a": {
+      "resolved": "packages/a",
+      "link": true
+    },
+    "node_modules/once": {
+      "name": "once",
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
+      "integrity": "sha1-WDsap3WWHUsROsF9nFC6753Xa9E=",
+      "dev": true,
+      "dependencies": {
+        "wrappy": "1"
+      }
+    },
+    "node_modules/wrappy": {
+      "name": "wrappy",
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
+      "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=",
+      "dev": true
+    },
+    "packages/a": {
+      "name": "a",
+      "version": "1.0.0",
+      "devDependencies": {
+        "once": "^1.4.0"
+      }
+    }
+  },
+  "dependencies": {
+    "a": {
+      "version": "file:packages/a"
+    },
+    "once": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
+      "integrity": "sha1-WDsap3WWHUsROsF9nFC6753Xa9E=",
+      "dev": true,
+      "requires": {
+        "wrappy": "1"
+      }
+    },
+    "wrappy": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
+      "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=",
+      "dev": true
+    }
+  }
+}
diff --git a/test/fixtures/workspaces-transitive-deps-virtual/package.json b/test/fixtures/workspaces-transitive-deps-virtual/package.json
new file mode 100644
index 000000000..91c627055
--- /dev/null
+++ b/test/fixtures/workspaces-transitive-deps-virtual/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspaces-transitive-deps",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-transitive-deps/package.json b/test/fixtures/workspaces-transitive-deps/package.json
new file mode 100644
index 000000000..91c627055
--- /dev/null
+++ b/test/fixtures/workspaces-transitive-deps/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspaces-transitive-deps",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-transitive-deps/packages/a/package.json b/test/fixtures/workspaces-transitive-deps/packages/a/package.json
new file mode 100644
index 000000000..b1d8baa8c
--- /dev/null
+++ b/test/fixtures/workspaces-transitive-deps/packages/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "devDependencies": {
+    "once": "^1.4.0"
+  }
+}
diff --git a/test/fixtures/workspaces-version-unsatisfied-virtual/package-lock.json b/test/fixtures/workspaces-version-unsatisfied-virtual/package-lock.json
new file mode 100644
index 000000000..eeca401bd
--- /dev/null
+++ b/test/fixtures/workspaces-version-unsatisfied-virtual/package-lock.json
@@ -0,0 +1,59 @@
+{
+  "name": "workspaces-version-unsatisfied",
+  "version": "1.0.0",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "workspaces-version-unsatisfied",
+      "version": "1.0.0",
+      "workspaces": {
+        "packages": [
+          "packages/*"
+        ]
+      }
+    },
+    "node_modules/a": {
+      "resolved": "packages/a",
+      "link": true
+    },
+    "node_modules/abbrev": {
+      "resolved": "packages/abbrev",
+      "link": true
+    },
+    "packages/a": {
+      "name": "a",
+      "version": "1.0.0",
+      "dependencies": {
+        "abbrev": "=1.1.1"
+      }
+    },
+    "packages/a/node_modules/abbrev": {
+      "name": "abbrev",
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+      "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
+    },
+    "packages/abbrev": {
+      "name": "abbrev",
+      "version": "2.0.0"
+    }
+  },
+  "dependencies": {
+    "a": {
+      "version": "file:packages/a"
+    },
+    "abbrev": {
+      "version": "file:packages/abbrev"
+    },
+    "packages/a": {
+      "dependencies": {
+        "abbrev": {
+          "version": "1.1.1",
+          "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+          "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
+        }
+      }
+    }
+  }
+}
diff --git a/test/fixtures/workspaces-version-unsatisfied-virtual/package.json b/test/fixtures/workspaces-version-unsatisfied-virtual/package.json
new file mode 100644
index 000000000..6622e0690
--- /dev/null
+++ b/test/fixtures/workspaces-version-unsatisfied-virtual/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "workspaces-version-unsatisfied",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ]
+}
diff --git a/test/fixtures/workspaces-version-unsatisfied/package.json b/test/fixtures/workspaces-version-unsatisfied/package.json
new file mode 100644
index 000000000..48a2cffa1
--- /dev/null
+++ b/test/fixtures/workspaces-version-unsatisfied/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "workspaces-version-unsatisfied",
+  "version": "1.0.0",
+  "workspaces": [
+    "packages/*"
+  ]
+}
+
diff --git a/test/fixtures/workspaces-version-unsatisfied/packages/a/package.json b/test/fixtures/workspaces-version-unsatisfied/packages/a/package.json
new file mode 100644
index 000000000..925ed61e5
--- /dev/null
+++ b/test/fixtures/workspaces-version-unsatisfied/packages/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "abbrev": "=1.1.1"
+  }
+}
diff --git a/test/fixtures/workspaces-version-unsatisfied/packages/abbrev/package.json b/test/fixtures/workspaces-version-unsatisfied/packages/abbrev/package.json
new file mode 100644
index 000000000..36b0d44ae
--- /dev/null
+++ b/test/fixtures/workspaces-version-unsatisfied/packages/abbrev/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "abbrev",
+  "version": "2.0.0",
+  "description": "Like ruby's abbrev module, but in js",
+  "author": "Isaac Z. Schlueter <i@izs.me>"
+}
diff --git a/test/fixtures/workspaces-with-files-spec/d/package.json b/test/fixtures/workspaces-with-files-spec/d/package.json
new file mode 100644
index 000000000..391cb7e1e
--- /dev/null
+++ b/test/fixtures/workspaces-with-files-spec/d/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "d",
+  "version": "1.0.0",
+  "dependencies": {
+    "b": "^1.0.0"
+  }
+}
diff --git a/test/fixtures/workspaces-with-files-spec/package.json b/test/fixtures/workspaces-with-files-spec/package.json
new file mode 100644
index 000000000..55838a6c9
--- /dev/null
+++ b/test/fixtures/workspaces-with-files-spec/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "workspaces-with-files-spec",
+  "workspaces": [
+    "packages/*",
+    "!packages/c"
+  ],
+  "dependencies": {
+    "c": "file:packages/c",
+    "d": "file:d"
+  }
+}
diff --git a/test/fixtures/workspaces-with-files-spec/packages/a/package.json b/test/fixtures/workspaces-with-files-spec/packages/a/package.json
new file mode 100644
index 000000000..e3dcbda8f
--- /dev/null
+++ b/test/fixtures/workspaces-with-files-spec/packages/a/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "d": "^1.0.0"
+  }
+}
diff --git a/test/fixtures/workspaces-with-files-spec/packages/b/package.json b/test/fixtures/workspaces-with-files-spec/packages/b/package.json
new file mode 100644
index 000000000..c2d84cc12
--- /dev/null
+++ b/test/fixtures/workspaces-with-files-spec/packages/b/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "b",
+  "version": "1.0.0"
+}
diff --git a/test/fixtures/workspaces-with-files-spec/packages/c/package.json b/test/fixtures/workspaces-with-files-spec/packages/c/package.json
new file mode 100644
index 000000000..abd338493
--- /dev/null
+++ b/test/fixtures/workspaces-with-files-spec/packages/c/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "c",
+  "version": "1.0.0"
+}
diff --git a/test/node.js b/test/node.js
index 389e6e3c4..d824c5f67 100644
--- a/test/node.js
+++ b/test/node.js
@@ -1134,6 +1134,7 @@ t.test('has install script', t => {
   t.end()
 })
 
+
 t.test('legacy peer dependencies', t => {
   const root = new Node({
     pkg: {
@@ -1162,3 +1163,75 @@ t.test('legacy peer dependencies', t => {
   t.equal(root.edgesOut.size, 0, 'should have no edges out')
   t.end()
 })
+
+t.test('set workspaces', t => {
+  const root = new Node({
+    pkg: { name: 'workspaces_root' },
+    path: '/home/user/projects/workspaces_root',
+    realpath: '/home/user/projects/workspaces_root',
+  })
+
+  root.workspaces = new Map([
+    ['foo', '/home/user/projects/workspaces_root/foo'],
+    ['bar', '/home/user/projects/workspaces_root/bar'],
+  ])
+
+  t.matchSnapshot(root, 'should setup edges out for each workspace')
+  t.end()
+})
+
+t.test('get workspaces', t => {
+  const root = new Node({
+    pkg: { name: 'workspaces_root' },
+    path: '/home/user/projects/workspaces_root',
+    realpath: '/home/user/projects/workspaces_root',
+  })
+
+  t.equal(root.workspaces, null, 'should default to null when no workspaces defined')
+
+  const ws = new Map()
+  root.workspaces = ws
+
+  t.equal(root.workspaces, ws, 'should match set value')
+  t.end()
+})
+
+t.test('replace workspaces', t => {
+  const root = new Node({
+    pkg: { name: 'workspaces_root' },
+    path: '/home/user/projects/workspaces_root',
+    realpath: '/home/user/projects/workspaces_root',
+  })
+
+  root.workspaces = new Map([
+    ['foo', '/home/user/projects/workspaces_root/foo'],
+    ['bar', '/home/user/projects/workspaces_root/bar'],
+  ])
+
+  const ws = new Map()
+  root.workspaces = ws
+
+  t.equal(root.workspaces, ws, 'should remove previously set workspaces')
+  t.end()
+})
+
+t.test('replace workspaces keeping existing edges out', t => {
+  const root = new Node({
+    pkg: { name: 'workspaces_root' },
+    path: '/home/user/projects/workspaces_root',
+    realpath: '/home/user/projects/workspaces_root',
+  })
+
+  root.workspaces = new Map([
+    ['foo', '/home/user/projects/workspaces_root/foo'],
+  ])
+
+  const ws = new Map([
+    ['foo', '/home/user/projects/workspaces_root/foo'],
+    ['bar', '/home/user/projects/workspaces_root/bar'],
+  ])
+  root.workspaces = ws
+
+  t.equal(root.workspaces, ws, 'should keep existing edges out')
+  t.end()
+})