ls: show installed but unmet peer deps

Any completely missing peer deps are filled in in the package tree, but
with only a name and the version with which it is required, and some
additional, derived metadata. However, if the dep does exist, but simply
is the wrong version, it is still marked as a missing peer dep.

This patch makes it so that `npm ls` does not hide *all* "missing" peer
deps, but just the ones that are not installed in some way already.

See https://npm.community/t/4770

lib/ls.js

@@ -305,7 +305,7 @@ function filterFound (root, args) {
     if (!markDeps) continue
     Object.keys(markDeps).forEach(function (depName) {
       var dep = markDeps[depName]
-      if (dep.peerMissing) return
+      if (dep.peerMissing && !dep._from) return
       dep._parent = markPkg
       for (var ii = 0; ii < args.length; ii++) {
         var argName = args[ii][0]

test/tap/ls-peer.js

@@ -0,0 +1,124 @@
+'use strict'
+const path = require('path')
+const test = require('tap').test
+const Tacks = require('tacks')
+const File = Tacks.File
+const Symlink = Tacks.Symlink
+const Dir = Tacks.Dir
+const common = require('../common-tap.js')
+
+const basedir = path.join(__dirname, path.basename(__filename, '.js'))
+const testdir = path.join(basedir, 'testdir')
+const cachedir = path.join(basedir, 'cache')
+const globaldir = path.join(basedir, 'global')
+const tmpdir = path.join(basedir, 'tmp')
+
+const conf = {
+  cwd: testdir,
+  env: common.newEnv().extend({
+    npm_config_cache: cachedir,
+    npm_config_tmp: tmpdir,
+    npm_config_prefix: globaldir,
+    npm_config_registry: common.registry,
+    npm_config_loglevel: 'warn'
+  })
+}
+
+const fixture = new Tacks(Dir({
+  cache: Dir(),
+  global: Dir(),
+  tmp: Dir(),
+  testdir: Dir({
+    'package.json': File({
+      name: 'fixture',
+      version: '1.0.0',
+      dependencies: {
+        dep: 'file:dep-1.0.0.tgz',
+        'peer-dep': 'file:peer-dep-2.0.0.tgz'
+      }
+    }),
+    // Source dir
+    // dep: Dir({
+    //   'package.json': File({
+    //     name: 'dep',
+    //     version: '1.0.0',
+    //     peerDependencies: {
+    //       'peer-dep': 'file:peer-dep-1.0.0.tgz'
+    //     }
+    //   })
+    // }),
+    'dep-1.0.0.tgz': File(new Buffer(
+      '1f8b0800000000000003ed8f3d0ec2300c853be71451661a1cd166e8cc45' +
+      'a2d654e1278d92c200eadd491a60ea462584946fb1f5fc9e655bd59e548f' +
+      '5b9b2a3ffac1142b0300b2aae8921e1152d062574b10424a08bed0d4d10f' +
+      '6b1fb2c4d58fca8553bedd937ea19ffa273c08a5cca80bb286b20e2ddb44' +
+      'e186ceebc1444d70e090548be8f668d174685a8d3e8c63fc3529633a040e' +
+      'fa8ccd5b28e7381ffb3b0bce894ce4d70f6732994c66e60975aec5690008' +
+      '0000',
+      'hex'
+    )),
+    // Source dir
+    // 'peer-dep': Dir({
+    //   'package.json': File({
+    //     name: 'peer-dep',
+    //     version: '2.0.0'
+    //   })
+    // }),
+    'peer-dep-1.0.0.tgz': File(new Buffer(
+      '1f8b08000000000000032b484cce4e4c4fd52f80d07a59c5f9790c540606' +
+      '06066626260ad8c4c1c0d45c81c1d8d4ccc0d0d0cccc00a80ec830353500' +
+      'd2d4760836505a5c925804740aa5e640bca200a78708a8e6525050ca4bcc' +
+      '4d55b252502a484d2dd24d492d50d2018996a5161567e6e781240cf50cf4' +
+      '0c94b86ab906dab9a360148c8251300aa80400c1c67f6300080000',
+      'hex'
+    )),
+    'peer-dep-2.0.0.tgz': File(new Buffer(
+      '1f8b08000000000000032b484cce4e4c4fd52f80d07a59c5f9790c540606' +
+      '06066626260ad8c4c1c0d45c81c1d8d4ccc0d0d0cccc00a80ec830353500' +
+      'd2d4760836505a5c925804740aa5e640bca200a78708a8e6525050ca4bcc' +
+      '4d55b252502a484d2dd24d492d50d2018996a5161567e6e781248cf40cf4' +
+      '0c94b86ab906dab9a360148c8251300aa80400cb30060800080000',
+      'hex'
+    ))
+  })
+}))
+
+function setup () {
+  cleanup()
+  fixture.create(basedir)
+}
+
+function cleanup () {
+  fixture.remove(basedir)
+}
+
+test('setup', t => {
+  setup()
+  return common.fakeRegistry.listen().then(() => common.npm(['install'], conf))
+})
+
+test('list warns about unmet peer dependency', t => {
+  return common.npm(['ls'], conf).then(([code, stdout, stderr]) => {
+    t.is(code, 1, 'command ran not ok')
+    t.comment(stdout.trim())
+    t.comment(stderr.trim())
+    t.match(stdout, 'UNMET PEER DEPENDENCY peer-dep@2.0.0')
+    t.match(stderr, 'npm ERR! peer dep missing: peer-dep@file:peer-dep-1.0.0.tgz, required by dep@1.0.0')
+  })
+})
+
+test('list shows installed but unmet peer dependency', t => {
+  return common.npm(['ls', 'peer-dep'], conf).then(([code, stdout, stderr]) => {
+    t.is(code, 1, 'command ran not ok')
+    t.comment(stdout.trim())
+    t.comment(stderr.trim())
+    t.match(stdout, 'UNMET PEER DEPENDENCY peer-dep@2.0.0')
+    t.match(stderr, 'npm ERR! peer dep missing: peer-dep@file:peer-dep-1.0.0.tgz, required by dep@1.0.0')
+  })
+})
+
+test('cleanup', t => {
+  common.fakeRegistry.close()
+  cleanup()
+  t.done()
+})