Add support for Composer v2

.travis.yml

@@ -17,6 +17,9 @@ matrix:
     - php: 7.1
     - php: 7.2
     - php: 7.3
+    - php: 7.3
+      env:
+        - COMPOSER_SNAPSHOT=true
     - php: 7.4
       env:
         - deps=high
@@ -41,13 +44,15 @@ install:
   # flags to pass to install
   - flags="--ansi --prefer-dist --no-interaction --optimize-autoloader --no-suggest --no-progress"
   # update deps to latest in case of high deps build
-  - if [[ "$deps" == "high" ]]; then composer config platform.php 7.2.4; composer update $flags; fi
-  # install dependencies using system provided composer binary
+  - if [[ $deps == 'high' ]]; then composer config platform.php 7.2.4; composer update $flags; fi
+  # install dependencies
   - composer install $flags
+  # install snapshot of composer
+  - if [[ $COMPOSER_SNAPSHOT == 'true' ]]; then composer require composer/composer:^2.0@dev --prefer-stable --update-with-dependencies; fi
 
 script:
   - ./vendor/bin/simple-phpunit
 
 after_script:
-  - if [[ "$TRAVIS_PHP_VERSION" == '7.4' ]]; then composer require php-coveralls/php-coveralls ; fi
-  - if [[ "$TRAVIS_PHP_VERSION" == '7.4' ]]; then php vendor/bin/php-coveralls -v ; fi
+  - if [[ $TRAVIS_PHP_VERSION == '7.4' ]]; then composer require php-coveralls/php-coveralls; fi
+  - if [[ $TRAVIS_PHP_VERSION == '7.4' ]]; then php vendor/bin/php-coveralls -v; fi

composer.json

@@ -11,10 +11,10 @@
     ],
     "require": {
         "php": "^5.3.2 || ^7.0",
-        "composer-plugin-api": "^1.0"
+        "composer-plugin-api": "^1.0 || ^2.0"
     },
     "require-dev": {
-        "composer/composer": "^1.0",
+        "composer/composer": "^1.0 || ^2.0",
         "symfony/phpunit-bridge": "^3.4"
     },
     "conflict": {

src/ExcludeFilePlugin.php

@@ -43,6 +43,34 @@ public function activate(Composer $composer, IOInterface $io)
         $this->composer = $composer;
     }
 
+    /**
+     * Remove any hooks from Composer.
+     *
+     * @codeCoverageIgnore
+     *
+     * @param  Composer    $composer The Composer instance.
+     * @param  IOInterface $io       The Input/Output instance.
+     * @return void
+     */
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        // no need to deactivate anything
+    }
+
+    /**
+     * Prepare the plugin to be uninstalled.
+     *
+     * @codeCoverageIgnore
+     *
+     * @param  Composer    $composer The Composer instance.
+     * @param  IOInterface $io       The Input/Output instance.
+     * @return void
+     */
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        // no need to uninstall anything
+    }
+
     /**
      * Gets a list of event names this subscriber wants to listen to.
      *