support local npm package searches (#3105)

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>

docs/resources/npm.md.erb

@@ -22,6 +22,14 @@ where
 * `('npm_package_name')` must specify an NPM package, such as `'bower'` or `'statsd'`
 * `be_installed` is a valid matcher for this resource
 
+You can also specify additional options:
+
+    describe npm('npm_package_name', path: '/path/to/project') do
+      it { should be_installed }
+    end
+
+The `path` specifies a folder, that contains a `node_modules` subdirectory. It emulates running `npm` inside the specified folder. This way you can inspect local NPM installations as well as global ones.
+
 <br>
 
 ## Examples

lib/resources/npm.rb

@@ -1,5 +1,7 @@
 # encoding: utf-8
 
+require 'shellwords'
+
 module Inspec::Resources
   class NpmPackage < Inspec.resource(1)
     name 'npm'
@@ -10,17 +12,28 @@ module Inspec::Resources
       describe npm('bower') do
         it { should be_installed }
       end
+
+      describe npm('tar', path: '/path/to/project') do
+        it { should be_installed }
+      end
     "
 
-    def initialize(package_name)
+    def initialize(package_name, opts = {})
       @package_name = package_name
+      @location = opts[:path]
       @cache = nil
     end
 
     def info
       return @info if defined?(@info)
 
-      cmd = inspec.command("npm ls -g --json #{@package_name}")
+      if @location
+        npm = "cd #{Shellwords.escape @location} && npm"
+      else
+        npm = 'npm -g'
+      end
+
+      cmd = inspec.command("#{npm} ls --json #{@package_name}")
       @info = {
         name: @package_name,
         type: 'npm',

test/helper.rb

@@ -254,7 +254,8 @@ class MockLoader
       '/opt/chef/embedded/bin/gem list --local -a -q ^chef-sugar$' => cmd.call('gem-list-local-a-q-chef-sugar'),
       'c:\opscode\chef\embedded\bin\gem.bat list --local -a -q ^json$' => cmd.call('gem-list-local-a-q-json'),
       '/opt/opscode/embedded/bin/gem list --local -a -q ^knife-backup$' => cmd.call('gem-list-local-a-q-knife-backup'),
-      'npm ls -g --json bower' => cmd.call('npm-ls-g--json-bower'),
+      'npm -g ls --json bower' => cmd.call('npm-g-ls--json-bower'),
+      'cd /path/to/project && npm ls --json bower' => cmd.call('npm-ls--json-bower'),
       "Rscript -e 'packageVersion(\"DBI\")'" => cmd.call('r-print-version'),
       "Rscript -e 'packageVersion(\"DoesNotExist\")'" => cmd.call('r-print-version-not-installed'),
       "perl -le 'eval \"require $ARGV[0]\" and print $ARGV[0]->VERSION or exit 1' DBD::Pg" => cmd.call('perl-print-version'),

test/unit/mock/cmd/npm-ls--json-bower

@@ -0,0 +1,9 @@
+{
+  "dependencies": {
+    "bower": {
+      "version": "1.4.2",
+      "from": "bower@*",
+      "resolved": "https://registry.npmjs.org/bower/-/bower-1.4.1.tgz"
+    }
+  }
+}

test/unit/resources/npm_test.rb

@@ -17,4 +17,16 @@ describe 'Inspec::Resources::Npm' do
     _(resource.installed?).must_equal true
     _(resource.info).must_equal pkg
   end
+
+  it 'verify npm package in local folder' do
+    resource = load_resource('npm', 'bower', path: '/path/to/project')
+    pkg = {
+      name: 'bower',
+      version: '1.4.2',
+      type: 'npm',
+      installed: true,
+    }
+    _(resource.installed?).must_equal true
+    _(resource.info).must_equal pkg
+  end
 end