link: fix `npm link package-name`

It was broken two ways– it expected npm to accept a string for the
list of packages to install. And it expected a install to return
a list of packages added, not a tree.

PR-URL: https://github.com/npm/npm/pull/8782

Fixes: #8766

4 files changed, 24 insertions, 9 deletions

diff --git a/lib/install.js b/lib/install.js
index 40344e90a..c29ec5e9a 100644
--- a/lib/install.js
+++ b/lib/install.js
@@ -257,7 +257,7 @@ Installer.prototype.run = function (cb) {
         log.warn('error', postInstallEr.message)
         log.verbose('error', postInstallEr.stack)
       }
-      cb(installEr || postInstallEr, self.idealTree)
+      cb(installEr || postInstallEr, self.getInstalledModules(), self.idealTree)
     })
   })
 }
@@ -560,6 +560,16 @@ Installer.prototype.normalizeTree = function (log, cb) {
   }))
 }
 
+Installer.prototype.getInstalledModules = function () {
+  return this.differences.filter(function (action) {
+    var mutation = action[0]
+    return (mutation === 'add' || mutation === 'update')
+  }).map(function (action) {
+    var child = action[1]
+    return [child.package._id, child.path]
+  })
+}
+
 Installer.prototype.printInstalled = function (cb) {
   validate('F', arguments)
   log.silly('install', 'printInstalled')
diff --git a/lib/link.js b/lib/link.js
index b5d7f9d36..2e65b7fbd 100644
--- a/lib/link.js
+++ b/lib/link.js
@@ -59,11 +59,14 @@ function linkInstall (pkgs, cb) {
 
     function n (er, data) {
       if (er) return cb(er, data)
-      // install returns [ [folder, pkgId], ... ]
-      // but we definitely installed just one thing.
-      var d = data.filter(function (d) { return !d[3] })
-      var what = npa(d[0][0])
-      pp = d[0][1]
+      // we want the ONE thing that was installed into the global dir
+      var installed = data.filter(function (info) {
+        var folder = info[1]
+        return path.resolve(folder, '..') === npm.globalDir
+      })
+      var id = installed[0][0]
+      pp = installed[0][1]
+      var what = npa(id)
       pkg = what.name
       target = path.resolve(npm.dir, pkg)
       next()
@@ -85,7 +88,7 @@ function linkInstall (pkgs, cb) {
     fs.lstat(pp, function (er, st) {
       if (er) {
         rp = pp
-        return npm.commands.install(t, pkg, n)
+        return npm.commands.install(t, [pkg], n)
       } else if (!st.isSymbolicLink()) {
         rp = pp
         next()
@@ -99,6 +102,7 @@ function linkInstall (pkgs, cb) {
     })
 
     function next () {
+      if (npm.config.get('dry-run')) return resultPrinter(pkg, pp, target, rp, cb)
       chain(
         [
           [npm.commands, 'unbuild', [target]],
@@ -132,6 +136,7 @@ function linkPkg (folder, cb_) {
       er = new Error('Package must have a name field to be linked')
       return cb(er)
     }
+    if (npm.config.get('dry-run')) return resultPrinter(path.basename(me), me, target, cb)
     var target = path.resolve(npm.globalDir, d.name)
     symlink(me, target, false, true, function (er) {
       if (er) return cb(er)
diff --git a/test/tap/peer-deps-invalid.js b/test/tap/peer-deps-invalid.js
index 7c33e63ed..4ce2d6b26 100644
--- a/test/tap/peer-deps-invalid.js
+++ b/test/tap/peer-deps-invalid.js
@@ -77,7 +77,7 @@ test('installing dependencies that have conflicting peerDependencies', function
         registry: common.registry
       },
       function () {
-        npm.commands.install([], function (err, tree) {
+        npm.commands.install([], function (err, additions, tree) {
           t.error(err)
           t.is(tree.warnings.length, 2)
           t.is(tree.warnings[0].code, 'EPEERINVALID')
diff --git a/test/tap/peer-deps-without-package-json.js b/test/tap/peer-deps-without-package-json.js
index 781686f62..bfb91162c 100644
--- a/test/tap/peer-deps-without-package-json.js
+++ b/test/tap/peer-deps-without-package-json.js
@@ -51,7 +51,7 @@ test('installing a peerDeps-using package without package.json', function (t) {
       registry: common.registry,
       cache: cache
     }, function () {
-      npm.install(common.registry + '/ok.js', function (err, result) {
+      npm.install(common.registry + '/ok.js', function (err, additions, result) {
         t.ifError(err, 'installed ok.js')
 
         t.ok(