Support installing plugins from single PHP file URLs

features/plugin-install.feature

@@ -274,6 +274,99 @@ Feature: Install WordPress plugins
       Error: No plugins installed.
       """
 
+  Scenario: Install plugin from a single PHP file URL
+    Given a WP install
+
+    When I run `wp plugin install https://gist.githubusercontent.com/westonruter/dec7d190060732e29a09751ab99cc549/raw/d55866c2fc82ab16f8909ce73fc89986ab28d727/pwa-manifest-short-name.php --activate`
+    Then STDOUT should contain:
+      """
+      Installing
+      """
+    And STDOUT should contain:
+      """
+      Downloading plugin file from
+      """
+    And STDOUT should contain:
+      """
+      Plugin installed successfully.
+      """
+    And STDOUT should contain:
+      """
+      Activating
+      """
+    And the wp-content/plugins/pwa-manifest-short-name.php file should exist
+
+    When I run `wp plugin list --field=name`
+    Then STDOUT should contain:
+      """
+      pwa-manifest-short-name
+      """
+
+    When I run `wp plugin list --name=pwa-manifest-short-name --field=status`
+    Then STDOUT should be:
+      """
+      active
+      """
+
+  Scenario: Install plugin from a single PHP file URL with --force flag
+    Given a WP install
+
+    When I run `wp plugin install https://gist.githubusercontent.com/westonruter/dec7d190060732e29a09751ab99cc549/raw/d55866c2fc82ab16f8909ce73fc89986ab28d727/pwa-manifest-short-name.php`
+    Then STDOUT should contain:
+      """
+      Plugin installed successfully.
+      """
+    And the wp-content/plugins/pwa-manifest-short-name.php file should exist
+
+    When I try `wp plugin install https://gist.githubusercontent.com/westonruter/dec7d190060732e29a09751ab99cc549/raw/d55866c2fc82ab16f8909ce73fc89986ab28d727/pwa-manifest-short-name.php`
+    Then STDERR should contain:
+      """
+      Warning: Plugin already installed.
+      """
+    And STDOUT should contain:
+      """
+      Success: Plugin already installed.
+      """
+
+    When I run `wp plugin install https://gist.githubusercontent.com/westonruter/dec7d190060732e29a09751ab99cc549/raw/d55866c2fc82ab16f8909ce73fc89986ab28d727/pwa-manifest-short-name.php --force`
+    Then STDOUT should contain:
+      """
+      Plugin installed successfully.
+      """
+    And the wp-content/plugins/pwa-manifest-short-name.php file should exist
+
+  Scenario: Install plugin from a GitHub Gist page URL
+    Given a WP install
+
+    When I run `wp plugin install https://gist.github.com/westonruter/dec7d190060732e29a09751ab99cc549 --activate`
+    Then STDOUT should contain:
+      """
+      Gist resolved to raw file URL.
+      """
+    And STDOUT should contain:
+      """
+      Installing
+      """
+    And STDOUT should contain:
+      """
+      Downloading plugin file from
+      """
+    And STDOUT should contain:
+      """
+      Plugin installed successfully.
+      """
+    And STDOUT should contain:
+      """
+      Activating
+      """
+    And the wp-content/plugins/pwa-manifest-short-name.php file should exist
+
+    When I run `wp plugin list --name=pwa-manifest-short-name --field=status`
+    Then STDOUT should be:
+      """
+      active
+      """
+
   Scenario: Install plugin using WordPress.org directory URL
     Given a WP install
 

src/Plugin_Command.php

@@ -1004,7 +1004,7 @@ protected function filter_item_list( $items, $args ) {
 	 * ## OPTIONS
 	 *
 	 * <plugin|zip|url>...
-	 * : One or more plugins to install. Accepts a plugin slug, the path to a local zip file, a URL to a remote zip file, or a URL to a WordPress.org plugin directory.
+	 * : One or more plugins to install. Accepts a plugin slug, the path to a local zip file, a URL to a remote zip file or PHP file, or a URL to a WordPress.org plugin directory.
 	 *
 	 * [--version=<version>]
 	 * : If set, get that particular version from wordpress.org, instead of the
@@ -1087,6 +1087,11 @@ protected function filter_item_list( $items, $args ) {
 	 *     Plugin updated successfully
 	 *     Success: Installed 1 of 1 plugins.
 	 *
+	 *     # Install from a remote PHP file
+	 *     $ wp plugin install https://example.com/my-plugin.php
+	 *     Installing My Plugin (1.0.0)
+	 *     Downloading plugin file from https://example.com/my-plugin.php...
+	 *
 	 *     # Install a plugin with all its dependencies
 	 *     $ wp plugin install my-plugin --with-dependencies
 	 *     Installing Required Plugin 1 (1.2.3)