diff --git a/tests/IntegrationTest/InstallUpdateEventsTest.php b/tests/IntegrationTest/InstallUpdateEventsTest.php
new file mode 100644
index 00000000..c106d0c7
--- /dev/null
+++ b/tests/IntegrationTest/InstallUpdateEventsTest.php
@@ -0,0 +1,342 @@
+<?php
+
+/**
+ * This file is part of the Dealerdirect PHP_CodeSniffer Standards
+ * Composer Installer Plugin package.
+ *
+ * @copyright 2022 PHPCodeSniffer Composer Installer Contributors
+ * @license MIT
+ */
+
+namespace Dealerdirect\Composer\Plugin\Installers\PHPCodeSniffer\Tests\IntegrationTest;
+
+use Dealerdirect\Composer\Plugin\Installers\PHPCodeSniffer\Plugin;
+use Dealerdirect\Composer\Plugin\Installers\PHPCodeSniffer\Tests\TestCase;
+
+/**
+ * Test that the plugin is hooked into the right events and doesn't get triggered when those events are blocked.
+ *
+ * These tests verify that:
+ * - The plugin gets triggered on install/update/require/remove/reinstall events.
+ * - The plugin doesn't run when Composer is run with `--no-plugins`.
+ * - The plugin does run when Composer is run with `--no-scripts`.
+ * - Can be run on-demand via a custom script.
+ *
+ * This test is about Composer and the plugin, so does not need to be tested against multiple PHPCS versions.
+ * The behaviour also shouldn't differ between a global vs local Composer install, so only testing one type.
+ *
+ * {@internal Note: `create-project` can not be tested as it needs a Packagist registered project, which would
+ * mean that the test would not use the _current_ version of the plugin, but a previous release.}
+ *
+ * @link https://github.com/PHPCSStandards/composer-installer/issues/4
+ * @link https://github.com/PHPCSStandards/composer-installer/pull/5
+ */
+final class InstallUpdateEventsTest extends TestCase
+{
+    private $composerConfig = array(
+        'name'        => 'phpcs-composer-installer/plugin-events-test',
+        'require-dev' => array(
+            'dealerdirect/phpcodesniffer-composer-installer' => '*',
+            'phpcs-composer-installer/dummy-subdir'          => '*',
+            'ehime/hello-world'                              => '^1.0',
+        ),
+        'scripts'     => array(
+            'custom-runner'    => array(
+                'Dealerdirect\\Composer\\Plugin\\Installers\\PHPCodeSniffer\\Plugin::run',
+            ),
+            'post-install-cmd' => array(
+                'echo "post-install-cmd successfully run"',
+            ),
+        ),
+    );
+
+    /**
+     * Set up test environment before each test.
+     */
+    protected function set_up()
+    {
+        $this->createTestEnvironment();
+    }
+
+    /**
+     * Clean up after each test.
+     */
+    protected function tear_down()
+    {
+        $this->removeTestEnvironment();
+    }
+
+    /**
+     * Test that the plugin runs when Composer is invoked with an action triggering a hooked in event.
+     *
+     * @dataProvider dataComposerActions
+     *
+     * @param string $action The Composer action to run.
+     *
+     * @return void
+     */
+    public function testPluginRuns($action)
+    {
+        $this->writeComposerJsonFile($this->composerConfig, static::$tempLocalPath);
+
+        $command = sprintf(
+            'composer %s -v --no-ansi --working-dir=%s',
+            $action,
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = $this->executeCliCommand($command);
+
+        $this->assertSame(0, $result['exitcode'], "Exitcode for composer $action did not match 0");
+
+        if ($this->willPluginOutputShow() === true) {
+            $this->assertStringContainsString(
+                Plugin::MESSAGE_RUNNING_INSTALLER,
+                $result['stdout'],
+                "Output from composer $action does not show the plugin as running while it should be."
+            );
+        } else {
+            /*
+             * Composer edge-case where it doesn't show plugin output.
+             * Verify the plugin has run by checking via PHPCS.
+             */
+            $result = $this->executeCliCommand('"vendor/bin/phpcs" --config-show', static::$tempLocalPath);
+            $this->assertSame(0, $result['exitcode'], 'Exitcode for "--config-show" did not match 0');
+            $this->assertStringContainsString(
+                'installed_paths:',
+                $result['stdout'],
+                'PHPCS has no paths to external standards registered.'
+            );
+        }
+    }
+
+    /**
+     * Data provider.
+     *
+     * @link https://getcomposer.org/doc/03-cli.md
+     * @link https://getcomposer.org/doc/articles/scripts.md#event-names
+     *
+     * @return array
+     */
+    public function dataComposerActions()
+    {
+        return array(
+            'install'   => array('install'),
+            'update'    => array('update'),
+            'require'   => array('require --dev phpcs-composer-installer/dummy-src'),
+            'remove'    => array('remove --dev ehime/hello-world'),
+        );
+
+        $data = array();
+        foreach ($actions as $action) {
+            $data[$action] = array($action);
+        }
+
+        return $data;
+    }
+
+    /**
+     * Test that the plugin runs when Composer reinstall is run for a project
+     * with a require(-dev) for the plugin.
+     *
+     * @link https://github.com/composer/composer/issues/10508
+     *
+     * @return void
+     */
+    public function testPluginRunsOnReinstall()
+    {
+        if (version_compare(\COMPOSER_VERSION, '2.2.6', '<') === true) {
+            $this->markTestSkipped('Plugins don\'t run on reinstall prior to Composer 2.2.6 - Composer bug #10508');
+        }
+
+        $this->writeComposerJsonFile($this->composerConfig, static::$tempLocalPath);
+
+        /*
+         * 1. Can only reinstall on something which is already installed, so install first.
+         */
+        $command = sprintf('composer install -v --no-ansi --working-dir=%s', escapeshellarg(static::$tempLocalPath));
+        $result  = $this->executeCliCommand($command);
+        $this->assertSame(0, $result['exitcode'], 'Exitcode for composer install did not match 0');
+
+        // Track what installed standards this resulted in.
+        $installedPaths = $this->executeCliCommand('"vendor/bin/phpcs" --config-show', static::$tempLocalPath);
+        $this->assertSame(0, $installedPaths['exitcode'], 'Exitcode for "--config-show" did not match 0 (install)');
+
+        /*
+         * 2. Reinstall PHPCS.
+         */
+        $command = sprintf(
+            'composer reinstall squizlabs/php_codesniffer -v --no-ansi --working-dir=%s',
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = $this->executeCliCommand($command);
+        $this->assertSame(0, $result['exitcode'], 'Exitcode for composer reinstall did not match 0');
+
+        // Verify the plugin ran.
+        $this->assertStringContainsString(
+            Plugin::MESSAGE_RUNNING_INSTALLER,
+            $result['stdout'],
+            "Output from composer reinstall does not show the plugin as running while it should be."
+        );
+
+        /*
+         * 3. Ensure the installed paths are the same before and after the reinstall.
+         */
+        $reinstalledPaths = $this->executeCliCommand('"vendor/bin/phpcs" --config-show', static::$tempLocalPath);
+        $this->assertSame(0, $reinstalledPaths['exitcode'], 'Exitcode for "--config-show" did not match 0 (reinstall)');
+
+        $expected = $this->configShowToPathsArray($installedPaths['stdout']);
+        $actual   = $this->configShowToPathsArray($reinstalledPaths['stdout']);
+
+        // Verify that the same paths are registered on install as well as reinstall.
+        $this->assertSame($expected, $actual);
+    }
+
+    /**
+     * Test that the plugin runs (or doesn't run) when Composer is invoked with the --no-scripts argument.
+     *
+     * Note: the behaviour of Composer changed in 2.1.2. Prior to that, `--no-scripts` would
+     * also stop plugins from running. As of Composer 2.1.2, `--no-scripts` and `--no-plugins`
+     * function independently of each other.
+     * {@link https://github.com/composer/composer/pull/9942}
+     *
+     * @return void
+     */
+    public function testPluginRunsOnInstallWithNoScripts()
+    {
+        $this->writeComposerJsonFile($this->composerConfig, static::$tempLocalPath);
+
+        $command = sprintf(
+            'composer install --no-scripts -v --no-ansi --working-dir=%s',
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = $this->executeCliCommand($command);
+
+        $this->assertSame(0, $result['exitcode'], 'Exitcode for composer install did not match 0');
+
+        if (version_compare(\COMPOSER_VERSION, '2.1.2', '>=') === true) {
+            $this->assertStringContainsString(
+                Plugin::MESSAGE_RUNNING_INSTALLER,
+                $result['stdout'],
+                'Output from running Composer install missing expected contents.'
+            );
+        } else {
+            // Composer 1.x.
+            $this->assertStringNotContainsString(
+                Plugin::MESSAGE_RUNNING_INSTALLER,
+                $result['stdout'],
+                'Output from running Composer install contains unexpected contents.'
+            );
+        }
+    }
+
+    /**
+     * Test that the plugin doesn't run when Composer init is run with a require for the plugin
+     * (as that doesn't install anything yet).
+     *
+     * Note: this test "should" be in the NonInstallUpdateEventsTest, but it requires a clean environment,
+     * so it ended up being more straight-forward to include it in this test class.
+     *
+     * @return void
+     */
+    public function testPluginDoesNotRunsOnInitWithRequire()
+    {
+        $command = sprintf(
+            'composer init'
+            . ' --name=phpcs-composer-installer/plugin-events-init-test'
+            . ' --type=project'
+            . ' --require-dev=dealerdirect/phpcodesniffer-composer-installer:*,phpcs-composer-installer/dummy-subdir:*'
+            . ' -v --no-ansi --working-dir=%s',
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = $this->executeCliCommand($command);
+
+        $this->assertSame(0, $result['exitcode'], 'Exitcode for composer init did not match 0');
+
+        $this->assertStringNotContainsString(
+            Plugin::MESSAGE_RUNNING_INSTALLER,
+            $result['stdout'],
+            'Output from composer init shows the plugin as running when it shouldn\'t be.'
+        );
+    }
+
+    /**
+     * Test that the plugin does not run when Composer is invoked with the --no-plugins argument.
+     *
+     * @return void
+     */
+    public function testPluginDoesNotRunOnInstallWithNoPlugins()
+    {
+        $this->writeComposerJsonFile($this->composerConfig, static::$tempLocalPath);
+
+        // Verify the plugin doesn't run when install is run with --no-plugins.
+        $command = sprintf(
+            'composer install --no-plugins -v --no-ansi --working-dir=%s',
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = $this->executeCliCommand($command);
+
+        $this->assertSame(0, $result['exitcode'], 'Exitcode for composer install did not match 0');
+
+        $this->assertStringNotContainsString(
+            Plugin::MESSAGE_RUNNING_INSTALLER,
+            $result['stdout'],
+            'Output from composer install shows the plugin as running when it shouldn\'t .'
+        );
+
+        // Verify the plugin doesn't run when post-install-cmd is run with --no-plugins.
+        $command = sprintf(
+            'composer run-script post-install-cmd --no-plugins -v --no-ansi --working-dir=%s',
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = $this->executeCliCommand($command);
+
+        $this->assertSame(0, $result['exitcode'], 'Exitcode for composer post-install-cmd did not match 0');
+
+        $this->assertStringNotContainsString(
+            Plugin::MESSAGE_RUNNING_INSTALLER,
+            $result['stdout'],
+            'Output from composer post-install-cmd shows the plugin as running when it shouldn\'t be.'
+        );
+    }
+
+    /**
+     * Test that the plugin does not run when Composer is invoked with the --no-plugins AND --no-scripts arguments,
+     * but can then still be invoked via a custom script.
+     *
+     * @return void
+     */
+    public function testPluginDoesNotRunWithNoScriptsNoPluginsAndRunsViaScript()
+    {
+        $this->writeComposerJsonFile($this->composerConfig, static::$tempLocalPath);
+
+        // Verify the plugin doesn't run when install is run with --no-plugins and --no-scripts.
+        $command = sprintf(
+            'composer install --no-scripts --no-plugins -v --no-ansi --working-dir=%s',
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = $this->executeCliCommand($command);
+
+        $this->assertSame(0, $result['exitcode'], 'Exitcode for composer install did not match 0');
+
+        $this->assertStringNotContainsString(
+            Plugin::MESSAGE_RUNNING_INSTALLER,
+            $result['stdout'],
+            'Output from composer install shows the plugin as running when it shouldn\'t be.'
+        );
+
+        // Verify that the plugin can be run via a custom script.
+        $script = sprintf(
+            'composer custom-runner -v --no-ansi --working-dir=%s',
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result = $this->executeCliCommand($script);
+
+        $this->assertSame(0, $result['exitcode'], 'Exitcode for running Composer script did not match 0');
+
+        $this->assertStringContainsString(
+            Plugin::MESSAGE_RUNNING_INSTALLER,
+            $result['stdout'],
+            'Output from running Composer script missing expected contents.'
+        );
+    }
+}
diff --git a/tests/IntegrationTest/NonInstallUpdateEventsTest.php b/tests/IntegrationTest/NonInstallUpdateEventsTest.php
new file mode 100644
index 00000000..7e675112
--- /dev/null
+++ b/tests/IntegrationTest/NonInstallUpdateEventsTest.php
@@ -0,0 +1,136 @@
+<?php
+
+/**
+ * This file is part of the Dealerdirect PHP_CodeSniffer Standards
+ * Composer Installer Plugin package.
+ *
+ * @copyright 2022 PHPCodeSniffer Composer Installer Contributors
+ * @license MIT
+ */
+
+namespace Dealerdirect\Composer\Plugin\Installers\PHPCodeSniffer\Tests\IntegrationTest;
+
+use Dealerdirect\Composer\Plugin\Installers\PHPCodeSniffer\Plugin;
+use Dealerdirect\Composer\Plugin\Installers\PHPCodeSniffer\Tests\TestCase;
+
+/**
+ * Test that the plugin doesn't get triggered on events it isn't hooked into.
+ *
+ * This test is about Composer and the plugin, so does not need to be tested against multiple PHPCS versions.
+ * The behaviour also shouldn't differ between a global vs local Composer install, so only testing one type.
+ */
+final class NonInstallUpdateEventsTest extends TestCase
+{
+    private static $composerConfig = array(
+        'name'        => 'phpcs-composer-installer/non-plugin-events-test',
+        'require-dev' => array(
+            'dealerdirect/phpcodesniffer-composer-installer' => '*',
+            'phpcs-composer-installer/dummy-subdir'          => '*',
+        ),
+    );
+
+    /**
+     * Set up test environment at the start of the tests.
+     */
+    public static function set_up_before_class()
+    {
+        static::createTestEnvironment();
+
+        static::writeComposerJsonFile(self::$composerConfig, static::$tempLocalPath);
+
+        /*
+         * Install dependencies.
+         * As the commands being run in these tests don't _change_ the environment, we only need to do this once.
+         */
+        $command = sprintf(
+            'composer install --no-plugins --no-ansi --working-dir=%s',
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = static::executeCliCommand($command);
+
+        if ($result['exitcode'] !== 0) {
+            throw new RuntimeException('`composer install` failed');
+        }
+    }
+
+    /**
+     * Clean up after all tests have run.
+     */
+    public static function tear_down_after_class()
+    {
+        static::removeTestEnvironment();
+    }
+
+    /**
+     * Test that the plugin doesn't run on commands for which it shouldn't.
+     *
+     * @dataProvider dataComposerActions
+     *
+     * @param string $action The Composer action to run.
+     *
+     * @return void
+     */
+    public function testPluginDoesNotRun($action)
+    {
+        $command = sprintf(
+            'composer %s -v --no-ansi --working-dir=%s',
+            $action,
+            escapeshellarg(static::$tempLocalPath)
+        );
+        $result  = $this->executeCliCommand($command);
+
+        $this->assertStringNotContainsString(
+            Plugin::MESSAGE_RUNNING_INSTALLER,
+            $result['stdout'],
+            "Output from composer $action shows the plugin as running when it shouldn't be."
+        );
+    }
+
+    /**
+     * Data provider.
+     *
+     * @link https://getcomposer.org/doc/03-cli.md
+     * @link https://getcomposer.org/doc/articles/scripts.md#event-names
+     *
+     * @return array
+     */
+    public function dataComposerActions()
+    {
+        $actions = array(
+            /*
+             * Composer actions which actually have events associated with them,
+             * but which the plugin is not hooked into.
+             */
+            'archive',
+            'dump-autoload',
+            'status',
+
+            /*
+             * Composer actions which don't have events associated with them (just to be sure).
+             */
+            'check-platform-reqs',
+            'config --list',
+            'depends',
+            'diagnose',
+            'fund',
+            'help',
+            'licenses',
+            'outdated',
+            'prohibits',
+            'search dealerdirect',
+            'show',
+            'suggests',
+            'validate',
+
+            // Excluded to prevent influencing other tests as the Composer version is important for most tests.
+            //'self-update',
+        );
+
+        $data = array();
+        foreach ($actions as $action) {
+            $data[$action] = array($action);
+        }
+
+        return $data;
+    }
+}