From 987ee45d01c219bf78506611bf8fd76cec0b82a6 Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Thu, 17 Sep 2020 15:31:16 -0700
Subject: [PATCH] Add `--strict-peer-deps` option

This is the CLI portion of https://github.com/npm/arborist/pull/136
---
 docs/content/using-npm/config.md               | 18 ++++++++++++++++++
 lib/utils/config.js                            |  3 ++-
 lib/utils/flat-options.js                      |  1 +
 .../test-lib-utils-config.js-TAP.test.js       |  9 ++++++---
 .../test-lib-utils-flat-options.js-TAP.test.js |  1 +
 5 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/docs/content/using-npm/config.md b/docs/content/using-npm/config.md
index 132f0bf580aac..2982e41dbbec7 100644
--- a/docs/content/using-npm/config.md
+++ b/docs/content/using-npm/config.md
@@ -1161,6 +1161,24 @@ should be polled while the user is completing authentication.
 
 If `--auth-type=sso`, the type of SSO type to use.
 
+#### strict-peer-deps
+
+* Default: false
+* Type: Boolean
+
+If set to `true`, and `--legacy-peer-deps` is not set, then _any_
+conflicting `peerDependencies` will be treated as an install failure, even
+if npm could reasonably guess the appropriate resolution based on non-peer
+dependency relationships.
+
+By default, conflicting `peerDependencies` in the dependency graph will be
+resolved using the nearest non-peer dependency specification, even if doing
+so will result in some packages receiving a peer dependency outside the
+range set in their package's `peerDependencies` object.  When such and
+override is performed, a warning is printed, explaining the conflict and
+the packages involved.  If `--strict-peer-deps` is set, then the warning is
+treated as a failure.
+
 #### strict-ssl
 
 * Default: true
diff --git a/lib/utils/config.js b/lib/utils/config.js
index a7fd131d45590..d273ae8a5c459 100644
--- a/lib/utils/config.js
+++ b/lib/utils/config.js
@@ -111,6 +111,7 @@ const defaults = {
   key: null,
   'legacy-bundling': false,
   'legacy-peer-deps': false,
+  'strict-peer-deps': false,
   link: false,
   'local-address': undefined,
   loglevel: 'notice',
@@ -229,7 +230,6 @@ const types = {
   group: [Number, String],
   'https-proxy': [null, url],
   'user-agent': String,
-  'ham-it-up': Boolean,
   heading: String,
   'if-present': Boolean,
   include: [Array, 'prod', 'dev', 'optional', 'peer'],
@@ -246,6 +246,7 @@ const types = {
   key: [null, String],
   'legacy-bundling': Boolean,
   'legacy-peer-deps': Boolean,
+  'strict-peer-deps': Boolean,
   link: Boolean,
   'local-address': getLocalAddresses(),
   loglevel: [
diff --git a/lib/utils/flat-options.js b/lib/utils/flat-options.js
index 2ace852d1e36a..d6decdbf79361 100644
--- a/lib/utils/flat-options.js
+++ b/lib/utils/flat-options.js
@@ -170,6 +170,7 @@ const flatOptions = npm => npm.flatOptions || Object.freeze({
   shell: npm.config.get('shell'),
   omit: buildOmitList(npm),
   legacyPeerDeps: npm.config.get('legacy-peer-deps'),
+  strictPeerDeps: npm.config.get('strict-peer-deps'),
 
   // npx stuff
   call: npm.config.get('call'),
diff --git a/tap-snapshots/test-lib-utils-config.js-TAP.test.js b/tap-snapshots/test-lib-utils-config.js-TAP.test.js
index eb3ad9e315044..771837959f20b 100644
--- a/tap-snapshots/test-lib-utils-config.js-TAP.test.js
+++ b/tap-snapshots/test-lib-utils-config.js-TAP.test.js
@@ -117,6 +117,7 @@ Object {
     "sign-git-tag": false,
     "sso-poll-frequency": 500,
     "sso-type": "oauth",
+    "strict-peer-deps": false,
     "strict-ssl": true,
     "tag": "latest",
     "tag-version-prefix": "v",
@@ -347,7 +348,6 @@ Object {
       "{Number TYPE}",
       "{String TYPE}",
     ],
-    "ham-it-up": "{Boolean TYPE}",
     "heading": "{String TYPE}",
     "https-proxy": Array [
       null,
@@ -495,6 +495,7 @@ Object {
       "oauth",
       "saml",
     ],
+    "strict-peer-deps": "{Boolean TYPE}",
     "strict-ssl": "{Boolean TYPE}",
     "tag": "{String TYPE}",
     "tag-version-prefix": "{String TYPE}",
@@ -625,6 +626,7 @@ Object {
     "sign-git-tag": false,
     "sso-poll-frequency": 500,
     "sso-type": "oauth",
+    "strict-peer-deps": false,
     "strict-ssl": true,
     "tag": "latest",
     "tag-version-prefix": "v",
@@ -855,7 +857,6 @@ Object {
       "{Number TYPE}",
       "{String TYPE}",
     ],
-    "ham-it-up": "{Boolean TYPE}",
     "heading": "{String TYPE}",
     "https-proxy": Array [
       null,
@@ -1003,6 +1004,7 @@ Object {
       "oauth",
       "saml",
     ],
+    "strict-peer-deps": "{Boolean TYPE}",
     "strict-ssl": "{Boolean TYPE}",
     "tag": "{String TYPE}",
     "tag-version-prefix": "{String TYPE}",
@@ -1133,6 +1135,7 @@ Object {
     "sign-git-tag": false,
     "sso-poll-frequency": 500,
     "sso-type": "oauth",
+    "strict-peer-deps": false,
     "strict-ssl": true,
     "tag": "latest",
     "tag-version-prefix": "v",
@@ -1363,7 +1366,6 @@ Object {
       "{Number TYPE}",
       "{String TYPE}",
     ],
-    "ham-it-up": "{Boolean TYPE}",
     "heading": "{String TYPE}",
     "https-proxy": Array [
       null,
@@ -1513,6 +1515,7 @@ Object {
       "oauth",
       "saml",
     ],
+    "strict-peer-deps": "{Boolean TYPE}",
     "strict-ssl": "{Boolean TYPE}",
     "tag": "{String TYPE}",
     "tag-version-prefix": "{String TYPE}",
diff --git a/tap-snapshots/test-lib-utils-flat-options.js-TAP.test.js b/tap-snapshots/test-lib-utils-flat-options.js-TAP.test.js
index 89a5527299f7d..d9aa8e8b631f3 100644
--- a/tap-snapshots/test-lib-utils-flat-options.js-TAP.test.js
+++ b/tap-snapshots/test-lib-utils-flat-options.js-TAP.test.js
@@ -111,6 +111,7 @@ Object {
   "signGitTag": "sign-git-tag",
   "ssoPollFrequency": undefined,
   "ssoType": undefined,
+  "strictPeerDeps": undefined,
   "strictSSL": "strict-ssl",
   "tag": "tag",
   "tagVersionPrefix": "tag-version-prefix",