[BUG] issue installing dependency when specified in both dev & peer

[mjeanroy]

Current Behavior:

When a dependency is specified as a devDependency and as a peerDependency, it is not installed. I tested it with [email protected], everything worked well with npm < 7.

Expected Behavior:

I expect that all dev dependencies should be installed.

Steps To Reproduce:

I created a very small repository to reproduce the issue, so you can just checkout it and install dependencies:

git clone [email protected]:mjeanroy/npm-7-bug-peer-dev.git
cd npm-7-bug-peer-dev
npm install

Environment:

• OS: MacOS 10.15.7
• Node: 15.0.0
• npm: 7.0.2

[isaacs]

This appears to be working as of npm 7.0.3 and 7.0.2. I get the same results in each.

$ git clone [email protected]:mjeanroy/npm-7-bug-peer-dev.git
Cloning into 'npm-7-bug-peer-dev'...
Krypton ▶ Requesting SSH authentication from phone
Krypton ▶ Success. Request Allowed ✔
remote: Enumerating objects: 4, done.
remote: Counting objects: 100% (4/4), done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 4 (delta 0), reused 4 (delta 0), pack-reused 0
Receiving objects: 100% (4/4), done.

$  cd npm-7-bug-peer-dev
/Users/isaacs/dev/npm/arborist/npm-7-bug-peer-dev

$ npm install

added 6 packages, and audited 6 packages in 658ms

found 0 vulnerabilities

$ npm ls react
[email protected] /Users/isaacs/dev/npm/arborist/npm-7-bug-peer-dev
└── [email protected]


$ ls -laF node_modules/react/package.json
-rw-r--r--  1 isaacs  staff  882 Oct 26  1985 node_modules/react/package.json

Is it possible that --omit=peer or --omit=dev is set on your system, or --legacy-peer-deps?

[lpinca]

@isaacs it does not work with [email protected] shipped with Node.js v15.0.0.

$ node -v
v15.0.0

$ npm -v
7.0.2

$ git clone [email protected]:websockets/ws.git
Cloning into 'ws'...
remote: Enumerating objects: 9, done.
remote: Counting objects: 100% (9/9), done.
remote: Compressing objects: 100% (9/9), done.
remote: Total 14388 (delta 1), reused 5 (delta 0), pack-reused 14379
Receiving objects: 100% (14388/14388), 10.67 MiB | 1.77 MiB/s, done.
Resolving deltas: 100% (11784/11784), done.

$ cd ws

$ npm i
npm WARN deprecated [email protected]: this library is no longer supported
npm WARN deprecated [email protected]: request has been deprecated, see https://github.com/request/request/issues/3142

added 352 packages, and audited 352 packages in 16s

33 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities

$ npm ls utf-8-validate
[email protected] C:\Users\luigi\Desktop\ws
└── (empty)

utf-8-validate is a dev dependency and an optional peer dependency.

[lpinca]

The same happens with Node.js v15.0.1 and [email protected].

[mjeanroy]

@isaacs You're right, I had omit=peer in my ~/.npmrc, I did not see that.