From 61c1b93bfa4b766e698dd59e0111e7d3731209a8 Mon Sep 17 00:00:00 2001
From: "Mr. Example" <mrexample@users.noreply.github.com>
Date: Sat, 6 Jul 2019 10:32:29 +0300
Subject: [PATCH 01/11] Copy resolutions section from source package.json for
 yarn

---
 apps/rush-lib/src/api/PackageJsonEditor.ts            | 11 +++++++++++
 apps/rush-lib/src/logic/InstallManager.ts             |  9 +++++++++
 .../yarn-resolutions_2019-07-06-07-35.json            | 11 +++++++++++
 .../rush/yarn-resolutions_2019-07-06-07-35.json       | 11 +++++++++++
 common/reviews/api/node-core-library.api.md           |  1 +
 common/reviews/api/rush-lib.api.md                    |  2 ++
 libraries/node-core-library/src/IPackageJson.ts       |  6 ++++++
 7 files changed, 51 insertions(+)
 create mode 100644 common/changes/@microsoft/node-core-library/yarn-resolutions_2019-07-06-07-35.json
 create mode 100644 common/changes/@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json

diff --git a/apps/rush-lib/src/api/PackageJsonEditor.ts b/apps/rush-lib/src/api/PackageJsonEditor.ts
index 53a1ab85ad7..4cfa4f0bf43 100644
--- a/apps/rush-lib/src/api/PackageJsonEditor.ts
+++ b/apps/rush-lib/src/api/PackageJsonEditor.ts
@@ -72,6 +72,10 @@ export class PackageJsonEditor {
   // SemVer range in one of the other fields for consumers.  Thus "dependencies", "optionalDependencies",
   // and "peerDependencies" are mutually exclusive, but "devDependencies" is not.
   private readonly _devDependencies: Map<string, PackageJsonDependency>;
+
+  // NOTE: The "resolutions" is yarn specific featrue that controls package
+  // resolution override within yarn.
+  private readonly _resolutions: object;
   private _modified: boolean;
 
   private constructor(filepath: string, data: IPackageJson) {
@@ -81,6 +85,7 @@ export class PackageJsonEditor {
 
     this._dependencies = new Map<string, PackageJsonDependency>();
     this._devDependencies = new Map<string, PackageJsonDependency>();
+    this._resolutions = {};
 
     const dependencies: { [key: string]: string } = data.dependencies || {};
     const optionalDependencies: { [key: string]: string } = data.optionalDependencies || {};
@@ -125,6 +130,8 @@ export class PackageJsonEditor {
           new PackageJsonDependency(packageName, devDependencies[packageName], DependencyType.Dev, _onChange));
       });
 
+      this._resolutions = data.resolutions || {};
+
       Sort.sortMapKeys(this._dependencies);
       Sort.sortMapKeys(this._devDependencies);
 
@@ -167,6 +174,10 @@ export class PackageJsonEditor {
     return [...this._devDependencies.values()];
   }
 
+  public get resolutions(): object {
+    return { ...this._resolutions };
+  }
+
   public tryGetDependency(packageName: string): PackageJsonDependency | undefined {
     return this._dependencies.get(packageName);
   }
diff --git a/apps/rush-lib/src/logic/InstallManager.ts b/apps/rush-lib/src/logic/InstallManager.ts
index 383e1a005b5..f575c74ea50 100644
--- a/apps/rush-lib/src/logic/InstallManager.ts
+++ b/apps/rush-lib/src/logic/InstallManager.ts
@@ -12,6 +12,7 @@ import * as os from 'os';
 import * as path from 'path';
 import * as semver from 'semver';
 import * as tar from 'tar';
+import { isEmpty } from 'lodash';
 import * as globEscape from 'glob-escape';
 import {
   JsonFile,
@@ -677,6 +678,14 @@ export class InstallManager {
         }
       }
 
+      if (!isEmpty(packageJson.resolutions)) {
+        tempPackageJson.resolutions = tempPackageJson.resolutions || {};
+        commonPackageJson.resolutions = commonPackageJson.resolutions || {};
+
+        tempPackageJson.resolutions = packageJson.resolutions;
+        commonPackageJson.resolutions = { ...commonPackageJson.resolutions, ...packageJson.resolutions };
+      }
+
       // NPM expects the root of the tarball to have a directory called 'package'
       const npmPackageFolder: string = 'package';
 
diff --git a/common/changes/@microsoft/node-core-library/yarn-resolutions_2019-07-06-07-35.json b/common/changes/@microsoft/node-core-library/yarn-resolutions_2019-07-06-07-35.json
new file mode 100644
index 00000000000..a5aa522e27e
--- /dev/null
+++ b/common/changes/@microsoft/node-core-library/yarn-resolutions_2019-07-06-07-35.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/node-core-library",
+      "comment": "Add support of resolutuions section for yarn",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@microsoft/node-core-library",
+  "email": "MasterLambaster@gmail.com"
+}
\ No newline at end of file
diff --git a/common/changes/@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json b/common/changes/@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json
new file mode 100644
index 00000000000..4d73cde2d83
--- /dev/null
+++ b/common/changes/@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "Add support of resolutuions section for yarn",
+      "packageName": "@microsoft/rush",
+      "type": "none"
+    }
+  ],
+  "packageName": "@microsoft/rush",
+  "email": "MasterLambaster@gmail.com"
+}
\ No newline at end of file
diff --git a/common/reviews/api/node-core-library.api.md b/common/reviews/api/node-core-library.api.md
index ddf118c1584..35367957753 100644
--- a/common/reviews/api/node-core-library.api.md
+++ b/common/reviews/api/node-core-library.api.md
@@ -285,6 +285,7 @@ export interface INodePackageJson {
     peerDependencies?: IPackageJsonDependencyTable;
     private?: boolean;
     repository?: string;
+    resolutions?: Object;
     scripts?: IPackageJsonScriptTable;
     // @beta
     tsdocMetadata?: string;
diff --git a/common/reviews/api/rush-lib.api.md b/common/reviews/api/rush-lib.api.md
index 2f982d3720b..ef3e2541e83 100644
--- a/common/reviews/api/rush-lib.api.md
+++ b/common/reviews/api/rush-lib.api.md
@@ -204,6 +204,8 @@ export class PackageJsonEditor {
     // (undocumented)
     readonly name: string;
     // (undocumented)
+    readonly resolutions: object;
+    // (undocumented)
     saveIfModified(): boolean;
     // (undocumented)
     tryGetDependency(packageName: string): PackageJsonDependency | undefined;
diff --git a/libraries/node-core-library/src/IPackageJson.ts b/libraries/node-core-library/src/IPackageJson.ts
index 34021606b06..22801b6ce73 100644
--- a/libraries/node-core-library/src/IPackageJson.ts
+++ b/libraries/node-core-library/src/IPackageJson.ts
@@ -137,6 +137,12 @@ export interface IPackageJsonScriptTable {
    * A table of script hooks that a package manager or build tool may invoke.
    */
   scripts?: IPackageJsonScriptTable;
+
+  /**
+   * A table of package version resolutions. This feature is only available in
+   * yarn.
+   */
+  resolutions?: Object;
 }
 
 /**

From 7b3684c1bd5ee063c53ff34a85e12d934226b83e Mon Sep 17 00:00:00 2001
From: Alex <MasterLambaster@gmail.com>
Date: Wed, 17 Jul 2019 16:32:54 +0300
Subject: [PATCH 02/11] Apply copy suggestions from code review

Co-Authored-By: Ian Clanton-Thuon <iclanton@users.noreply.github.com>
---
 apps/rush-lib/src/api/PackageJsonEditor.ts                   | 5 ++++-
 .../node-core-library/yarn-resolutions_2019-07-06-07-35.json | 4 ++--
 .../@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json   | 4 ++--
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/apps/rush-lib/src/api/PackageJsonEditor.ts b/apps/rush-lib/src/api/PackageJsonEditor.ts
index 4cfa4f0bf43..364975dc90b 100644
--- a/apps/rush-lib/src/api/PackageJsonEditor.ts
+++ b/apps/rush-lib/src/api/PackageJsonEditor.ts
@@ -73,7 +73,7 @@ export class PackageJsonEditor {
   // and "peerDependencies" are mutually exclusive, but "devDependencies" is not.
   private readonly _devDependencies: Map<string, PackageJsonDependency>;
 
-  // NOTE: The "resolutions" is yarn specific featrue that controls package
+  // NOTE: The "resolutions" field is a yarn specific feature that controls package
   // resolution override within yarn.
   private readonly _resolutions: object;
   private _modified: boolean;
@@ -174,6 +174,9 @@ export class PackageJsonEditor {
     return [...this._devDependencies.values()];
   }
 
+  /**
+   * This field is a Yarn-specific feature that allows overriding of package resolution.
+   */
   public get resolutions(): object {
     return { ...this._resolutions };
   }
diff --git a/common/changes/@microsoft/node-core-library/yarn-resolutions_2019-07-06-07-35.json b/common/changes/@microsoft/node-core-library/yarn-resolutions_2019-07-06-07-35.json
index a5aa522e27e..826aaeb75db 100644
--- a/common/changes/@microsoft/node-core-library/yarn-resolutions_2019-07-06-07-35.json
+++ b/common/changes/@microsoft/node-core-library/yarn-resolutions_2019-07-06-07-35.json
@@ -2,10 +2,10 @@
   "changes": [
     {
       "packageName": "@microsoft/node-core-library",
-      "comment": "Add support of resolutuions section for yarn",
+      "comment": "Include the Yarn \"resolutions\" field in \"IPackageJson\".",
       "type": "minor"
     }
   ],
   "packageName": "@microsoft/node-core-library",
   "email": "MasterLambaster@gmail.com"
-}
\ No newline at end of file
+}
diff --git a/common/changes/@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json b/common/changes/@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json
index 4d73cde2d83..709b8d3aacc 100644
--- a/common/changes/@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json
+++ b/common/changes/@microsoft/rush/yarn-resolutions_2019-07-06-07-35.json
@@ -1,11 +1,11 @@
 {
   "changes": [
     {
-      "comment": "Add support of resolutuions section for yarn",
+      "comment": "Add support for the Yarn \"resolutions\" package.json feature.",
       "packageName": "@microsoft/rush",
       "type": "none"
     }
   ],
   "packageName": "@microsoft/rush",
   "email": "MasterLambaster@gmail.com"
-}
\ No newline at end of file
+}

From 213ce52eb00383b6b24240c1f0bcdbb2f521f42c Mon Sep 17 00:00:00 2001
From: "Mr. Example" <mrexample@users.noreply.github.com>
Date: Wed, 17 Jul 2019 16:55:37 +0300
Subject: [PATCH 03/11] Use resolutions only for yarn package manager

---
 apps/rush-lib/src/logic/InstallManager.ts | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/apps/rush-lib/src/logic/InstallManager.ts b/apps/rush-lib/src/logic/InstallManager.ts
index f575c74ea50..16c2f317c40 100644
--- a/apps/rush-lib/src/logic/InstallManager.ts
+++ b/apps/rush-lib/src/logic/InstallManager.ts
@@ -679,11 +679,12 @@ export class InstallManager {
       }
 
       if (!isEmpty(packageJson.resolutions)) {
-        tempPackageJson.resolutions = tempPackageJson.resolutions || {};
-        commonPackageJson.resolutions = commonPackageJson.resolutions || {};
+        // We do not expect resolutions key to be provided for package managers other than yarn
+        if (this._rushConfiguration.packageManager !== 'yarn') {
+          throw new Error("Unexpected 'resolutions' section found in package.json. Only yarn supports this feature.");
+        }
 
         tempPackageJson.resolutions = packageJson.resolutions;
-        commonPackageJson.resolutions = { ...commonPackageJson.resolutions, ...packageJson.resolutions };
       }
 
       // NPM expects the root of the tarball to have a directory called 'package'

From b1579fbe08c7a25e2af5042867b900f42bd6d667 Mon Sep 17 00:00:00 2001
From: Alex <MasterLambaster@gmail.com>
Date: Wed, 17 Jul 2019 16:57:51 +0300
Subject: [PATCH 04/11] Use more specific type based on code review suggestion

Co-Authored-By: Ian Clanton-Thuon <iclanton@users.noreply.github.com>
---
 libraries/node-core-library/src/IPackageJson.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/node-core-library/src/IPackageJson.ts b/libraries/node-core-library/src/IPackageJson.ts
index 22801b6ce73..43f8cdff640 100644
--- a/libraries/node-core-library/src/IPackageJson.ts
+++ b/libraries/node-core-library/src/IPackageJson.ts
@@ -142,7 +142,7 @@ export interface IPackageJsonScriptTable {
    * A table of package version resolutions. This feature is only available in
    * yarn.
    */
-  resolutions?: Object;
+  resolutions?: { [name: string]: string };
 }
 
 /**

From 87329b8308914d8d4c648477ef023c57eaeb48f3 Mon Sep 17 00:00:00 2001
From: Ian Clanton-Thuon <iclanton@users.noreply.github.com>
Date: Thu, 25 Jul 2019 17:55:13 -0700
Subject: [PATCH 05/11] Fix a typing.

---
 apps/rush-lib/src/api/PackageJsonEditor.ts  | 4 ++--
 common/reviews/api/node-core-library.api.md | 4 +++-
 common/reviews/api/rush-lib.api.md          | 5 +++--
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/apps/rush-lib/src/api/PackageJsonEditor.ts b/apps/rush-lib/src/api/PackageJsonEditor.ts
index 364975dc90b..b8311ec9738 100644
--- a/apps/rush-lib/src/api/PackageJsonEditor.ts
+++ b/apps/rush-lib/src/api/PackageJsonEditor.ts
@@ -75,7 +75,7 @@ export class PackageJsonEditor {
 
   // NOTE: The "resolutions" field is a yarn specific feature that controls package
   // resolution override within yarn.
-  private readonly _resolutions: object;
+  private readonly _resolutions: { [name: string]: string };
   private _modified: boolean;
 
   private constructor(filepath: string, data: IPackageJson) {
@@ -177,7 +177,7 @@ export class PackageJsonEditor {
   /**
    * This field is a Yarn-specific feature that allows overriding of package resolution.
    */
-  public get resolutions(): object {
+  public get resolutions(): { [name: string]: string } {
     return { ...this._resolutions };
   }
 
diff --git a/common/reviews/api/node-core-library.api.md b/common/reviews/api/node-core-library.api.md
index 35367957753..fdd44f22efd 100644
--- a/common/reviews/api/node-core-library.api.md
+++ b/common/reviews/api/node-core-library.api.md
@@ -285,7 +285,9 @@ export interface INodePackageJson {
     peerDependencies?: IPackageJsonDependencyTable;
     private?: boolean;
     repository?: string;
-    resolutions?: Object;
+    resolutions?: {
+        [name: string]: string;
+    };
     scripts?: IPackageJsonScriptTable;
     // @beta
     tsdocMetadata?: string;
diff --git a/common/reviews/api/rush-lib.api.md b/common/reviews/api/rush-lib.api.md
index ef3e2541e83..d285bcafec0 100644
--- a/common/reviews/api/rush-lib.api.md
+++ b/common/reviews/api/rush-lib.api.md
@@ -203,8 +203,9 @@ export class PackageJsonEditor {
     static load(filePath: string): PackageJsonEditor;
     // (undocumented)
     readonly name: string;
-    // (undocumented)
-    readonly resolutions: object;
+    readonly resolutions: {
+        [name: string]: string;
+    };
     // (undocumented)
     saveIfModified(): boolean;
     // (undocumented)

From 7e4347a182143c89e391042b2f5bffc0f7c2c74d Mon Sep 17 00:00:00 2001
From: Pete Gonzalez <4673363+octogonz@users.noreply.github.com>
Date: Thu, 13 May 2021 21:13:39 -0700
Subject: [PATCH 06/11] rush build

---
 common/reviews/api/rush-lib.api.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/common/reviews/api/rush-lib.api.md b/common/reviews/api/rush-lib.api.md
index a8a31314447..673e821f01c 100644
--- a/common/reviews/api/rush-lib.api.md
+++ b/common/reviews/api/rush-lib.api.md
@@ -260,6 +260,9 @@ export class PackageJsonEditor {
     static load(filePath: string): PackageJsonEditor;
     // (undocumented)
     get name(): string;
+    get resolutions(): {
+        [name: string]: string;
+    };
     // (undocumented)
     saveIfModified(): boolean;
     saveToObject(): IPackageJson;

From 25ecbce15275b89ae29e746e5da0d8d4999ac681 Mon Sep 17 00:00:00 2001
From: Pete Gonzalez <4673363+octogonz@users.noreply.github.com>
Date: Thu, 13 May 2021 22:05:14 -0700
Subject: [PATCH 07/11] PR feedback: model PackageJsonEditor.resolutions like
 the other PackageJsonDependency tables

---
 apps/rush-lib/src/api/PackageJsonEditor.ts    | 107 ++++++++++++------
 .../installManager/RushInstallManager.ts      |   7 +-
 common/reviews/api/rush-lib.api.md            |   8 +-
 3 files changed, 79 insertions(+), 43 deletions(-)

diff --git a/apps/rush-lib/src/api/PackageJsonEditor.ts b/apps/rush-lib/src/api/PackageJsonEditor.ts
index d328e6ee2da..49aa5037574 100644
--- a/apps/rush-lib/src/api/PackageJsonEditor.ts
+++ b/apps/rush-lib/src/api/PackageJsonEditor.ts
@@ -2,7 +2,7 @@
 // See LICENSE in the project root for license information.
 
 import * as semver from 'semver';
-import { Import, IPackageJson, JsonFile, Sort } from '@rushstack/node-core-library';
+import { Import, InternalError, IPackageJson, JsonFile, Sort } from '@rushstack/node-core-library';
 
 const lodash: typeof import('lodash') = Import.lazy('lodash', require);
 
@@ -13,7 +13,8 @@ export const enum DependencyType {
   Regular = 'dependencies',
   Dev = 'devDependencies',
   Optional = 'optionalDependencies',
-  Peer = 'peerDependencies'
+  Peer = 'peerDependencies',
+  YarnResolutions = 'resolutions'
 }
 
 /**
@@ -67,7 +68,7 @@ export class PackageJsonEditor {
 
   // NOTE: The "resolutions" field is a yarn specific feature that controls package
   // resolution override within yarn.
-  private readonly _resolutions: { [name: string]: string };
+  private readonly _resolutions: Map<string, PackageJsonDependency>;
   private _modified: boolean;
   private _sourceData: IPackageJson;
 
@@ -78,7 +79,7 @@ export class PackageJsonEditor {
 
     this._dependencies = new Map<string, PackageJsonDependency>();
     this._devDependencies = new Map<string, PackageJsonDependency>();
-    this._resolutions = {};
+    this._resolutions = new Map<string, PackageJsonDependency>();
 
     const dependencies: { [key: string]: string } = data.dependencies || {};
     const optionalDependencies: { [key: string]: string } = data.optionalDependencies || {};
@@ -145,8 +146,19 @@ export class PackageJsonEditor {
         );
       });
 
-      this._resolutions = data.resolutions || {};
+      Object.keys(data.resolutions || {}).forEach((packageName: string) => {
+        this._resolutions.set(
+          packageName,
+          new PackageJsonDependency(
+            packageName,
+            devDependencies[packageName],
+            DependencyType.YarnResolutions,
+            _onChange
+          )
+        );
+      });
 
+      // (Do not sort this._resolutions because order may be significant; the RFC is unclear about that.)
       Sort.sortMapKeys(this._dependencies);
       Sort.sortMapKeys(this._devDependencies);
     } catch (e) {
@@ -190,9 +202,12 @@ export class PackageJsonEditor {
 
   /**
    * This field is a Yarn-specific feature that allows overriding of package resolution.
+   *
+   * @see {@link https://github.com/yarnpkg/rfcs/blob/master/implemented/0000-selective-versions-resolutions.md
+   * | 0000-selective-versions-resolutions.md RFC}
    */
-  public get resolutions(): { [name: string]: string } {
-    return { ...this._resolutions };
+  public get resolutionsList(): ReadonlyArray<PackageJsonDependency> {
+    return [...this._resolutions.values()];
   }
 
   public tryGetDependency(packageName: string): PackageJsonDependency | undefined {
@@ -216,16 +231,23 @@ export class PackageJsonEditor {
     );
 
     // Rush collapses everything that isn't a devDependency into the dependencies
-    // field, so we need to set the value dependening on dependency type
-    if (
-      dependencyType === DependencyType.Regular ||
-      dependencyType === DependencyType.Optional ||
-      dependencyType === DependencyType.Peer
-    ) {
-      this._dependencies.set(packageName, dependency);
-    } else {
-      this._devDependencies.set(packageName, dependency);
+    // field, so we need to set the value depending on dependency type
+    switch (dependencyType) {
+      case DependencyType.Regular:
+      case DependencyType.Optional:
+      case DependencyType.Peer:
+        this._dependencies.set(packageName, dependency);
+        break;
+      case DependencyType.Dev:
+        this._devDependencies.set(packageName, dependency);
+        break;
+      case DependencyType.YarnResolutions:
+        this._resolutions.set(packageName, dependency);
+        break;
+      default:
+        throw new InternalError('Unsupported DependencyType');
     }
+
     this._modified = true;
   }
 
@@ -268,31 +290,36 @@ export class PackageJsonEditor {
     delete normalizedData.optionalDependencies;
     delete normalizedData.peerDependencies;
     delete normalizedData.devDependencies;
+    delete normalizedData.resolutions;
 
     const keys: string[] = [...this._dependencies.keys()].sort();
 
     for (const packageName of keys) {
       const dependency: PackageJsonDependency = this._dependencies.get(packageName)!;
 
-      if (dependency.dependencyType === DependencyType.Regular) {
-        if (!normalizedData.dependencies) {
-          normalizedData.dependencies = {};
-        }
-        normalizedData.dependencies[dependency.name] = dependency.version;
-      }
-
-      if (dependency.dependencyType === DependencyType.Optional) {
-        if (!normalizedData.optionalDependencies) {
-          normalizedData.optionalDependencies = {};
-        }
-        normalizedData.optionalDependencies[dependency.name] = dependency.version;
-      }
-
-      if (dependency.dependencyType === DependencyType.Peer) {
-        if (!normalizedData.peerDependencies) {
-          normalizedData.peerDependencies = {};
-        }
-        normalizedData.peerDependencies[dependency.name] = dependency.version;
+      switch (dependency.dependencyType) {
+        case DependencyType.Regular:
+          if (!normalizedData.dependencies) {
+            normalizedData.dependencies = {};
+          }
+          normalizedData.dependencies[dependency.name] = dependency.version;
+          break;
+        case DependencyType.Optional:
+          if (!normalizedData.optionalDependencies) {
+            normalizedData.optionalDependencies = {};
+          }
+          normalizedData.optionalDependencies[dependency.name] = dependency.version;
+          break;
+        case DependencyType.Peer:
+          if (!normalizedData.peerDependencies) {
+            normalizedData.peerDependencies = {};
+          }
+          normalizedData.peerDependencies[dependency.name] = dependency.version;
+          break;
+        case DependencyType.Dev: // uses this._devDependencies instead
+        case DependencyType.YarnResolutions: // uses this._resolutions instead
+        default:
+          throw new InternalError('Unsupported DependencyType');
       }
     }
 
@@ -307,6 +334,16 @@ export class PackageJsonEditor {
       normalizedData.devDependencies[dependency.name] = dependency.version;
     }
 
+    // (Do not sort this._resolutions because order may be significant; the RFC is unclear about that.)
+    for (const packageName of this._resolutions.keys()) {
+      const dependency: PackageJsonDependency = this._resolutions.get(packageName)!;
+
+      if (!normalizedData.resolutions) {
+        normalizedData.resolutions = {};
+      }
+      normalizedData.resolutions[dependency.name] = dependency.version;
+    }
+
     return normalizedData;
   }
 }
diff --git a/apps/rush-lib/src/logic/installManager/RushInstallManager.ts b/apps/rush-lib/src/logic/installManager/RushInstallManager.ts
index 567804d3392..a9717f5d104 100644
--- a/apps/rush-lib/src/logic/installManager/RushInstallManager.ts
+++ b/apps/rush-lib/src/logic/installManager/RushInstallManager.ts
@@ -8,7 +8,6 @@ import * as os from 'os';
 import * as path from 'path';
 import * as semver from 'semver';
 import * as ssri from 'ssri';
-import { isEmpty } from 'lodash';
 import {
   JsonFile,
   Text,
@@ -257,15 +256,15 @@ export class RushInstallManager extends BaseInstallManager {
         }
       }
 
-      if (!isEmpty(packageJson.resolutions)) {
+      if (packageJson.resolutionsList.length > 0) {
         // We do not expect resolutions key to be provided for package managers other than yarn
         if (this.rushConfiguration.packageManager !== 'yarn') {
           throw new Error(
-            "Unexpected 'resolutions' section found in package.json. Only yarn supports this feature."
+            "Unexpected 'resolutions' section found in package.json. Only Yarn supports this feature."
           );
         }
 
-        tempPackageJson.resolutions = packageJson.resolutions;
+        tempPackageJson.resolutions = packageJson.saveToObject().resolutions;
       }
 
       // Example: "C:\MyRepo\common\temp\projects\my-project-2"
diff --git a/common/reviews/api/rush-lib.api.md b/common/reviews/api/rush-lib.api.md
index 673e821f01c..fad59779419 100644
--- a/common/reviews/api/rush-lib.api.md
+++ b/common/reviews/api/rush-lib.api.md
@@ -87,7 +87,9 @@ export const enum DependencyType {
     // (undocumented)
     Peer = "peerDependencies",
     // (undocumented)
-    Regular = "dependencies"
+    Regular = "dependencies",
+    // (undocumented)
+    YarnResolutions = "resolutions"
 }
 
 // @public
@@ -260,9 +262,7 @@ export class PackageJsonEditor {
     static load(filePath: string): PackageJsonEditor;
     // (undocumented)
     get name(): string;
-    get resolutions(): {
-        [name: string]: string;
-    };
+    get resolutionsList(): ReadonlyArray<PackageJsonDependency>;
     // (undocumented)
     saveIfModified(): boolean;
     saveToObject(): IPackageJson;

From f3f32d917ed73d77b98202ebc915c6ef3d9c3b58 Mon Sep 17 00:00:00 2001
From: Pete Gonzalez <4673363+octogonz@users.noreply.github.com>
Date: Thu, 13 May 2021 22:05:59 -0700
Subject: [PATCH 08/11] rush change

---
 .../yarn-resolutions_2021-05-14-05-05.json            | 11 +++++++++++
 .../yarn-resolutions_2021-05-14-05-05.json            | 11 +++++++++++
 .../yarn-resolutions_2021-05-14-05-05.json            | 11 +++++++++++
 .../rundown/yarn-resolutions_2021-05-14-05-05.json    | 11 +++++++++++
 4 files changed, 44 insertions(+)
 create mode 100644 common/changes/@microsoft/rush-stack-compiler-3.8/yarn-resolutions_2021-05-14-05-05.json
 create mode 100644 common/changes/@microsoft/rush-stack-compiler-3.9/yarn-resolutions_2021-05-14-05-05.json
 create mode 100644 common/changes/@rushstack/node-core-library/yarn-resolutions_2021-05-14-05-05.json
 create mode 100644 common/changes/@rushstack/rundown/yarn-resolutions_2021-05-14-05-05.json

diff --git a/common/changes/@microsoft/rush-stack-compiler-3.8/yarn-resolutions_2021-05-14-05-05.json b/common/changes/@microsoft/rush-stack-compiler-3.8/yarn-resolutions_2021-05-14-05-05.json
new file mode 100644
index 00000000000..e85748c5e9f
--- /dev/null
+++ b/common/changes/@microsoft/rush-stack-compiler-3.8/yarn-resolutions_2021-05-14-05-05.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush-stack-compiler-3.8",
+      "comment": "",
+      "type": "none"
+    }
+  ],
+  "packageName": "@microsoft/rush-stack-compiler-3.8",
+  "email": "4673363+octogonz@users.noreply.github.com"
+}
\ No newline at end of file
diff --git a/common/changes/@microsoft/rush-stack-compiler-3.9/yarn-resolutions_2021-05-14-05-05.json b/common/changes/@microsoft/rush-stack-compiler-3.9/yarn-resolutions_2021-05-14-05-05.json
new file mode 100644
index 00000000000..35751848f72
--- /dev/null
+++ b/common/changes/@microsoft/rush-stack-compiler-3.9/yarn-resolutions_2021-05-14-05-05.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush-stack-compiler-3.9",
+      "comment": "",
+      "type": "none"
+    }
+  ],
+  "packageName": "@microsoft/rush-stack-compiler-3.9",
+  "email": "4673363+octogonz@users.noreply.github.com"
+}
\ No newline at end of file
diff --git a/common/changes/@rushstack/node-core-library/yarn-resolutions_2021-05-14-05-05.json b/common/changes/@rushstack/node-core-library/yarn-resolutions_2021-05-14-05-05.json
new file mode 100644
index 00000000000..a18f56bf958
--- /dev/null
+++ b/common/changes/@rushstack/node-core-library/yarn-resolutions_2021-05-14-05-05.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/node-core-library",
+      "comment": "",
+      "type": "none"
+    }
+  ],
+  "packageName": "@rushstack/node-core-library",
+  "email": "4673363+octogonz@users.noreply.github.com"
+}
\ No newline at end of file
diff --git a/common/changes/@rushstack/rundown/yarn-resolutions_2021-05-14-05-05.json b/common/changes/@rushstack/rundown/yarn-resolutions_2021-05-14-05-05.json
new file mode 100644
index 00000000000..66ae345f9e7
--- /dev/null
+++ b/common/changes/@rushstack/rundown/yarn-resolutions_2021-05-14-05-05.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/rundown",
+      "comment": "",
+      "type": "none"
+    }
+  ],
+  "packageName": "@rushstack/rundown",
+  "email": "4673363+octogonz@users.noreply.github.com"
+}
\ No newline at end of file

From 1483b3db4b9bb932b41f4730382e7ba2acbd09ec Mon Sep 17 00:00:00 2001
From: Pete Gonzalez <4673363+octogonz@users.noreply.github.com>
Date: Thu, 13 May 2021 22:10:02 -0700
Subject: [PATCH 09/11] Improve type for IPackageJson.resolutions

---
 apps/rush-lib/src/api/PackageJsonEditor.ts      | 5 +++--
 common/reviews/api/node-core-library.api.md     | 4 +---
 libraries/node-core-library/src/IPackageJson.ts | 9 ++++++---
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/apps/rush-lib/src/api/PackageJsonEditor.ts b/apps/rush-lib/src/api/PackageJsonEditor.ts
index 49aa5037574..00b8df32ff6 100644
--- a/apps/rush-lib/src/api/PackageJsonEditor.ts
+++ b/apps/rush-lib/src/api/PackageJsonEditor.ts
@@ -203,8 +203,9 @@ export class PackageJsonEditor {
   /**
    * This field is a Yarn-specific feature that allows overriding of package resolution.
    *
-   * @see {@link https://github.com/yarnpkg/rfcs/blob/master/implemented/0000-selective-versions-resolutions.md
-   * | 0000-selective-versions-resolutions.md RFC}
+   * @remarks
+   * See the {@link https://github.com/yarnpkg/rfcs/blob/master/implemented/0000-selective-versions-resolutions.md
+   * | 0000-selective-versions-resolutions.md RFC} for details.
    */
   public get resolutionsList(): ReadonlyArray<PackageJsonDependency> {
     return [...this._resolutions.values()];
diff --git a/common/reviews/api/node-core-library.api.md b/common/reviews/api/node-core-library.api.md
index 1fd498a32a5..19ee114b8cb 100644
--- a/common/reviews/api/node-core-library.api.md
+++ b/common/reviews/api/node-core-library.api.md
@@ -465,9 +465,7 @@ export interface INodePackageJson {
     peerDependencies?: IPackageJsonDependencyTable;
     private?: boolean;
     repository?: string;
-    resolutions?: {
-        [name: string]: string;
-    };
+    resolutions?: Record<string, string>;
     scripts?: IPackageJsonScriptTable;
     // @beta
     tsdocMetadata?: string;
diff --git a/libraries/node-core-library/src/IPackageJson.ts b/libraries/node-core-library/src/IPackageJson.ts
index e461dd7f8b2..d215ff6e9bf 100644
--- a/libraries/node-core-library/src/IPackageJson.ts
+++ b/libraries/node-core-library/src/IPackageJson.ts
@@ -139,10 +139,13 @@ export interface INodePackageJson {
   scripts?: IPackageJsonScriptTable;
 
   /**
-   * A table of package version resolutions. This feature is only available in
-   * yarn.
+   * A table of package version resolutions. This feature is only implemented by the Yarn package manager.
+   *
+   * @remarks
+   * See the {@link https://github.com/yarnpkg/rfcs/blob/master/implemented/0000-selective-versions-resolutions.md
+   * | 0000-selective-versions-resolutions.md RFC} for details.
    */
-  resolutions?: { [name: string]: string };
+  resolutions?: Record<string, string>;
 }
 
 /**

From 5b4176a9bdfd39b15e2c4f0151d84c27f9a14c44 Mon Sep 17 00:00:00 2001
From: Pete Gonzalez <4673363+octogonz@users.noreply.github.com>
Date: Fri, 14 May 2021 15:18:59 -0700
Subject: [PATCH 10/11] PR feedback

---
 apps/rush-lib/src/api/PackageJsonEditor.ts | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/apps/rush-lib/src/api/PackageJsonEditor.ts b/apps/rush-lib/src/api/PackageJsonEditor.ts
index 00b8df32ff6..629792c3c96 100644
--- a/apps/rush-lib/src/api/PackageJsonEditor.ts
+++ b/apps/rush-lib/src/api/PackageJsonEditor.ts
@@ -86,6 +86,7 @@ export class PackageJsonEditor {
     const peerDependencies: { [key: string]: string } = data.peerDependencies || {};
 
     const devDependencies: { [key: string]: string } = data.devDependencies || {};
+    const resolutions: { [key: string]: string } = data.resolutions || {};
 
     const _onChange: () => void = this._onChange.bind(this);
 
@@ -146,12 +147,12 @@ export class PackageJsonEditor {
         );
       });
 
-      Object.keys(data.resolutions || {}).forEach((packageName: string) => {
+      Object.keys(resolutions || {}).forEach((packageName: string) => {
         this._resolutions.set(
           packageName,
           new PackageJsonDependency(
             packageName,
-            devDependencies[packageName],
+            resolutions[packageName],
             DependencyType.YarnResolutions,
             _onChange
           )

From 2db822e9ce7dad3fef60f18f4fdaf6ec4a35d556 Mon Sep 17 00:00:00 2001
From: Pete Gonzalez <4673363+octogonz@users.noreply.github.com>
Date: Fri, 14 May 2021 16:22:09 -0700
Subject: [PATCH 11/11] Do not report an error when the Yarn-specific
 "resolutions" package.json field is used without Yarn.  This check only
 worked with useWorkspaces=false, and there may be valid use cases for
 packages that target multiple package managers

---
 .../src/logic/installManager/RushInstallManager.ts   | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/apps/rush-lib/src/logic/installManager/RushInstallManager.ts b/apps/rush-lib/src/logic/installManager/RushInstallManager.ts
index a9717f5d104..92a8d361a9a 100644
--- a/apps/rush-lib/src/logic/installManager/RushInstallManager.ts
+++ b/apps/rush-lib/src/logic/installManager/RushInstallManager.ts
@@ -256,15 +256,11 @@ export class RushInstallManager extends BaseInstallManager {
         }
       }
 
-      if (packageJson.resolutionsList.length > 0) {
-        // We do not expect resolutions key to be provided for package managers other than yarn
-        if (this.rushConfiguration.packageManager !== 'yarn') {
-          throw new Error(
-            "Unexpected 'resolutions' section found in package.json. Only Yarn supports this feature."
-          );
+      if (this.rushConfiguration.packageManager === 'yarn') {
+        // This feature is only implemented by the Yarn package manager
+        if (packageJson.resolutionsList.length > 0) {
+          tempPackageJson.resolutions = packageJson.saveToObject().resolutions;
         }
-
-        tempPackageJson.resolutions = packageJson.saveToObject().resolutions;
       }
 
       // Example: "C:\MyRepo\common\temp\projects\my-project-2"