install: fix unclean unbuild of nested packages with bin

Previously, installed packages that contained node_modules with a .bin
directory woudn't get cleaned up correctly. After unbuild of that particular
package, npm would complain with ENOENT errors because the package directory
would be empty (without package.json), as it only contains the leftover
`node_modules/.bin` directory.

PR-URL: npm#11181
Credit: @chrisirhc
Reviewed-By: @othiym23
Fixes: npm#10887
Fixes: npm#10938

lib/unbuild.js

@@ -80,7 +80,12 @@ function rmBins (pkg, folder, parent, top, cb) {
     } else {
       gentlyRm(path.resolve(binRoot, b), true, folder, cb)
     }
-  }, cb)
+  }, gentlyRmBinRoot)
+
+  function gentlyRmBinRoot (err) {
+    if (err || top) return cb(err)
+    return gentlyRm(binRoot, true, parent, cb)
+  }
 }
 
 function rmMans (pkg, folder, parent, top, cb) {

test/tap/uninstall-link-clean.js

@@ -0,0 +1,117 @@
+var fs = require('graceful-fs')
+var path = require('path')
+var existsSync = fs.existsSync || path.existsSync
+
+var mkdirp = require('mkdirp')
+var osenv = require('osenv')
+var rimraf = require('rimraf')
+var test = require('tap').test
+
+var common = require('../common-tap.js')
+
+var pkg = path.join(__dirname, 'uninstall-link-clean')
+var dep = path.join(__dirname, 'dep')
+var work = path.join(__dirname, 'uninstall-link-clean-TEST')
+var modules = path.join(work, 'node_modules')
+
+var EXEC_OPTS = { cwd: work }
+
+var world = 'console.log("hello blrbld")\n'
+
+var json = {
+  name: 'package',
+  version: '0.0.0',
+  bin: {
+    hello: './world.js'
+  },
+  dependencies: {
+    'dep': 'file:../dep'
+  }
+}
+
+var pjDep = {
+  name: 'dep',
+  version: '0.0.0',
+  bin: {
+    hello: './world.js'
+  }
+}
+
+test('setup', function (t) {
+  cleanup()
+  mkdirp.sync(pkg)
+  fs.writeFileSync(
+    path.join(pkg, 'package.json'),
+    JSON.stringify(json, null, 2)
+  )
+  fs.writeFileSync(path.join(pkg, 'world.js'), world)
+
+  mkdirp.sync(dep)
+  fs.writeFileSync(
+    path.join(dep, 'package.json'),
+    JSON.stringify(pjDep, null, 2)
+  )
+  fs.writeFileSync(path.join(dep, 'world.js'), world)
+
+  mkdirp.sync(modules)
+  process.chdir(work)
+
+  t.end()
+})
+
+test('installing package with links', function (t) {
+  common.npm(
+    [
+      '--loglevel', 'silent',
+      'install', pkg
+    ],
+    EXEC_OPTS,
+    function (err, code) {
+      t.ifError(err, 'install ran to completion without error')
+      t.notOk(code, 'npm install exited with code 0')
+
+      t.ok(
+        existsSync(path.join(modules, 'package', 'package.json')),
+        'package installed'
+      )
+      t.ok(existsSync(path.join(modules, '.bin')), 'binary link directory exists')
+      t.ok(existsSync(path.join(modules, 'package', 'node_modules', '.bin')),
+        'nested binary link directory exists')
+
+      t.end()
+    }
+  )
+})
+
+test('uninstalling package with links', function (t) {
+  common.npm(
+    [
+      '--loglevel', 'silent',
+      'uninstall', 'package'
+    ],
+    EXEC_OPTS,
+    function (err, code) {
+      t.ifError(err, 'uninstall ran to completion without error')
+      t.notOk(code, 'npm uninstall exited with code 0')
+
+      t.notOk(existsSync(path.join(modules, 'package')),
+        'package directory no longer exists')
+      t.notOk(existsSync(path.join(modules, 'package', 'node_modules', '.bin')),
+        'nested binary link directory no longer exists')
+
+      t.end()
+    }
+  )
+})
+
+test('cleanup', function (t) {
+  cleanup()
+  t.end()
+})
+
+function cleanup () {
+  process.chdir(osenv.tmpdir())
+  rimraf.sync(dep)
+  rimraf.sync(work)
+  rimraf.sync(pkg)
+}