4 files changed, 48 insertions, 1 deletions
diff --git a/lib/license/finder/ext.rb b/lib/license/finder/ext.rb
index 70620be..3d8a463 100644
--- a/lib/license/finder/ext.rb
+++ b/lib/license/finder/ext.rb
@@ -4,11 +4,13 @@ require 'license/finder/ext/go_modules'
 require 'license/finder/ext/gradle'
 require 'license/finder/ext/license'
 require 'license/finder/ext/maven'
+require 'license/finder/ext/npm'
 require 'license/finder/ext/nuget'
 require 'license/finder/ext/package_manager'
 require 'license/finder/ext/pip'
 require 'license/finder/ext/pipenv'
 require 'license/finder/ext/shared_helpers'
+require 'license/finder/ext/yarn'
 
 # Apply patch to the JsonReport found in the `license_finder` gem.
 LicenseFinder::JsonReport.prepend(License::Management::Report)
diff --git a/lib/license/finder/ext/npm.rb b/lib/license/finder/ext/npm.rb
new file mode 100644
index 0000000..75c0855
--- /dev/null
+++ b/lib/license/finder/ext/npm.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module LicenseFinder
+  class NPM
+    def current_packages
+      NpmPackage.packages_from_json(npm_json, detected_package_path)
+    end
+
+    def prepare_command
+      lockfile? ? 'npm ci' : 'npm install --no-save'
+    end
+
+    def possible_package_paths
+      [project_path.join('package.json')]
+    end
+
+    def prepare
+      Dir.chdir(project_path) do
+        shell.execute("#{prepare_command} --production")
+      end
+    end
+
+    private
+
+    def lockfile?
+      File.exist?(project_path.join('package-lock.json'))
+    end
+
+    def npm_json
+      stdout, _stderr, status = Dir.chdir(project_path) do
+        shell.execute("npm list --json --long --production")
+      end
+      status.success? ? JSON.parse(stdout) : {}
+    end
+  end
+end
diff --git a/lib/license/finder/ext/yarn.rb b/lib/license/finder/ext/yarn.rb
new file mode 100644
index 0000000..cc2c029
--- /dev/null
+++ b/lib/license/finder/ext/yarn.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module LicenseFinder
+  class Yarn
+    def prepare_command
+      'yarn install --ignore-engines --ignore-scripts'
+    end
+  end
+end
diff --git a/lib/license/management/version.rb b/lib/license/management/version.rb
index 64d34f7..cfb570e 100644
--- a/lib/license/management/version.rb
+++ b/lib/license/management/version.rb
@@ -2,6 +2,6 @@
 
 module License
   module Management
-    VERSION = '3.7.5'
+    VERSION = '3.7.6'
   end
 end