diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index fe20f2caa..0bf7ddfae 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -36,6 +36,7 @@
         </include>
         <exclude>
             <file>./src/Composer/Autoload/ClassLoader.php</file>
+            <directory>./src/Composer/PHPStan/</directory>
         </exclude>
     </coverage>
 </phpunit>
diff --git a/src/Composer/Command/RemoveCommand.php b/src/Composer/Command/RemoveCommand.php
index f4717439e..3b8ed88af 100644
--- a/src/Composer/Command/RemoveCommand.php
+++ b/src/Composer/Command/RemoveCommand.php
@@ -85,7 +85,7 @@ EOT
     protected function execute(InputInterface $input, OutputInterface $output)
     {
         if ($input->getArgument('packages') === [] && !$input->getOption('unused')) {
-            throw new InvalidArgumentException('Not enough arguments (missing: "packages")');
+            throw new InvalidArgumentException('Not enough arguments (missing: "packages").');
         }
 
         $packages = $input->getArgument('packages');
diff --git a/tests/Composer/Test/Command/AuditCommandTest.php b/tests/Composer/Test/Command/AuditCommandTest.php
index 1b820b479..53041f33d 100644
--- a/tests/Composer/Test/Command/AuditCommandTest.php
+++ b/tests/Composer/Test/Command/AuditCommandTest.php
@@ -13,6 +13,7 @@
 namespace Composer\Test\Command;
 
 use Composer\Test\TestCase;
+use UnexpectedValueException;
 
 class AuditCommandTest extends TestCase
 {
@@ -24,5 +25,20 @@ class AuditCommandTest extends TestCase
         $appTester->run(['command' => 'audit']);
 
         $appTester->assertCommandIsSuccessful();
+        self::assertEquals('No packages - skipping audit.', trim($appTester->getDisplay(true)));
+    }
+
+    public function testErrorAuditingLockFileWhenItIsMissing(): void
+    {
+        $this->initTempComposer();
+        $this->createInstalledJson([self::getPackage()]);
+
+        $this->expectException(UnexpectedValueException::class);
+        $this->expectExceptionMessage(
+            "Valid composer.json and composer.lock files are required to run this command with --locked"
+        );
+
+        $appTester = $this->getApplicationTester();
+        $appTester->run(['command' => 'audit', '--locked' => true]);
     }
 }
diff --git a/tests/Composer/Test/Command/RemoveCommandTest.php b/tests/Composer/Test/Command/RemoveCommandTest.php
new file mode 100644
index 000000000..f34b0c761
--- /dev/null
+++ b/tests/Composer/Test/Command/RemoveCommandTest.php
@@ -0,0 +1,470 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Test\Command;
+
+use Composer\Json\JsonFile;
+use Composer\Package\Link;
+use Composer\Semver\Constraint\MatchAllConstraint;
+use Composer\Test\TestCase;
+use InvalidArgumentException;
+use Symfony\Component\Console\Command\Command;
+use UnexpectedValueException;
+
+class RemoveCommandTest extends TestCase
+{
+    public function testExceptionRunningWithNoRemovePackages(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Not enough arguments (missing: "packages").');
+
+        $appTester = $this->getApplicationTester();
+        $this->assertEquals(Command::FAILURE, $appTester->run(['command' => 'remove']));
+    }
+
+    public function testExceptionWhenRunningUnusedWithoutLockFile(): void
+    {
+        $this->initTempComposer();
+
+        $this->expectException(UnexpectedValueException::class);
+        $this->expectExceptionMessage('A valid composer.lock file is required to run this command with --unused');
+
+        $appTester = $this->getApplicationTester();
+        $this->assertEquals(Command::FAILURE, $appTester->run(['command' => 'remove', '--unused' => true]));
+    }
+
+    public function testWarningWhenRemovingNonExistentPackage(): void
+    {
+        $this->initTempComposer();
+        $this->createInstalledJson();
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['vendor1/package1']]));
+        self::assertStringStartsWith('<warning>vendor1/package1 is not required in your composer.json and has not been removed</warning>', trim($appTester->getDisplay(true)));
+    }
+
+    public function testWarningWhenRemovingPackageFromWrongType(): void
+    {
+        $this->initTempComposer([
+            'require' => [
+                'root/req' => '1.*',
+            ],
+        ]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/req'], '--dev' => true, '--no-update' => true, '--no-interaction' => true]));
+        self::assertSame('<warning>root/req could not be found in require-dev but it is present in require</warning>
+./composer.json has been updated', trim($appTester->getDisplay(true)));
+        $this->assertEquals(['require' => ['root/req' => '1.*']], (new JsonFile('./composer.json'))->read());
+    }
+
+    public function testWarningWhenRemovingPackageWithDeprecatedDependenciesFlag(): void
+    {
+        $this->initTempComposer([
+            'require' => [
+                'root/req' => '1.*',
+            ],
+        ]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/req'], '--update-with-dependencies' => true, '--no-update' => true, '--no-interaction' => true]));
+        self::assertSame('<warning>You are using the deprecated option "update-with-dependencies". This is now default behaviour. The --no-update-with-dependencies option can be used to remove a package without its dependencies.</warning>
+./composer.json has been updated', trim($appTester->getDisplay(true)));
+        $this->assertEmpty((new JsonFile('./composer.json'))->read());
+    }
+
+    public function testMessageOutputWhenNoUnusedPackagesToRemove(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0', 'require' => ['nested/req' => '^1']],
+                        ['name' => 'nested/req', 'version' => '1.1.0'],
+                    ],
+                ],
+            ],
+            'require' => [
+                'root/req' => '1.*',
+            ],
+        ]);
+
+        $requiredPackage = self::getPackage('root/req');
+        $requiredPackage->setRequires([
+            'nested/req' => new Link(
+                'root/req',
+                'nested/req',
+                new MatchAllConstraint(),
+                Link::TYPE_REQUIRE,
+                '^1'
+            )
+        ]);
+        $nestedPackage = self::getPackage('nested/req', '1.1.0');
+
+        $this->createInstalledJson([$requiredPackage, $nestedPackage]);
+        $this->createComposerLock([$requiredPackage, $nestedPackage]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', '--unused' => true, '--no-audit' => true, '--no-interaction' => true]));
+        self::assertSame('No unused packages to remove', trim($appTester->getDisplay(true)));
+    }
+
+    public function testRemoveUnusedPackage(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0'],
+                        ['name' => 'not/req', 'version' => '1.0.0'],
+                    ],
+                ]
+            ],
+            'require' => [
+                'root/req' => '1.*',
+            ],
+        ]);
+
+        $requiredPackage = self::getPackage('root/req');
+        $extraneousPackage = self::getPackage('not/req');
+
+        $this->createInstalledJson([$requiredPackage]);
+        $this->createComposerLock([$requiredPackage, $extraneousPackage]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', '--unused' => true, '--no-audit' => true, '--no-interaction' => true]));
+        self::assertStringStartsWith('<warning>not/req is not required in your composer.json and has not been removed</warning>', $appTester->getDisplay(true));
+        self::assertStringContainsString('Running composer update not/req', $appTester->getDisplay(true));
+        self::assertStringContainsString('- Removing not/req (1.0.0)', $appTester->getDisplay(true));
+    }
+
+    public function testRemovePackageByName(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0', 'type' => 'metapackage'],
+                        ['name' => 'root/another', 'version' => '1.0.0', 'type' => 'metapackage']
+                    ],
+                ],
+            ],
+            'require' => [
+                'root/req' => '1.*',
+                'root/another' => '1.*',
+            ],
+        ]);
+        $rootReqPackage = self::getPackage('root/req');
+        $rootAnotherPackage = self::getPackage('root/another');
+        // Set as a metapackage so that we can do the whole post-remove update & install process without Composer trying to download them (DownloadManager::getDownloaderForPackage).
+        $rootReqPackage->setType('metapackage');
+        $rootAnotherPackage->setType('metapackage');
+
+        $this->createInstalledJson([$rootReqPackage, $rootAnotherPackage]);
+        $this->createComposerLock([$rootReqPackage, $rootAnotherPackage]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/req'], '--no-audit' => true, '--no-interaction' => true]));
+        self::assertStringStartsWith('./composer.json has been updated', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('Running composer update root/req', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('Lock file operations: 0 installs, 0 updates, 1 removal', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('- Removing root/req (1.0.0)', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('Package operations: 0 installs, 0 updates, 1 removal', trim($appTester->getDisplay(true)));
+        self::assertEquals(['root/another' => '1.*'], (new JsonFile('./composer.json'))->read()['require']);
+        self::assertEquals([['name' => 'root/another', 'version' => '1.0.0', 'type' => 'metapackage']], (new JsonFile('./composer.lock'))->read()['packages']);
+    }
+
+    public function testRemovePackageByNameWithDryRun(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0', 'type' => 'metapackage'],
+                        ['name' => 'root/another', 'version' => '1.0.0', 'type' => 'metapackage']
+                    ],
+                ],
+            ],
+            'require' => [
+                'root/req' => '1.*',
+                'root/another' => '1.*',
+            ],
+        ]);
+        $rootReqPackage = self::getPackage('root/req');
+        $rootAnotherPackage = self::getPackage('root/another');
+        // Set as a metapackage so that we can do the whole post-remove update & install process without Composer trying to download them (DownloadManager::getDownloaderForPackage).
+        $rootReqPackage->setType('metapackage');
+        $rootAnotherPackage->setType('metapackage');
+
+        $this->createInstalledJson([$rootReqPackage, $rootAnotherPackage]);
+        $this->createComposerLock([$rootReqPackage, $rootAnotherPackage]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/req'], '--dry-run' => true, '--no-audit' => true, '--no-interaction' => true]));
+        self::assertStringContainsString('./composer.json has been updated', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('Running composer update root/req', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('Lock file operations: 0 installs, 0 updates, 1 removal', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('- Removing root/req (1.0.0)', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('Package operations: 0 installs, 0 updates, 1 removal', trim($appTester->getDisplay(true)));
+        self::assertEquals(['root/req' => '1.*', 'root/another' => '1.*'], (new JsonFile('./composer.json'))->read()['require']);
+        self::assertEquals([['name' => 'root/another', 'version' => '1.0.0', 'type' => 'metapackage'], ['name' => 'root/req', 'version' => '1.0.0', 'type' => 'metapackage']], (new JsonFile('./composer.lock'))->read()['packages']);
+    }
+
+    public function testRemoveAllowedPluginPackageWithNoOtherAllowedPlugins(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0', 'type' => 'metapackage'],
+                        ['name' => 'root/another', 'version' => '1.0.0', 'type' => 'metapackage']
+                    ],
+                ],
+            ],
+            'require' => [
+                'root/req' => '1.*',
+                'root/another' => '1.*',
+            ],
+            'config' => [
+                'allow-plugins' => [
+                    'root/req' => true,
+                ],
+            ],
+        ]);
+        $rootReqPackage = self::getPackage('root/req');
+        $rootAnotherPackage = self::getPackage('root/another');
+        // Set as a metapackage so that we can do the whole post-remove update & install process without Composer trying to download them (DownloadManager::getDownloaderForPackage).
+        $rootReqPackage->setType('metapackage');
+        $rootAnotherPackage->setType('metapackage');
+
+        $this->createInstalledJson([$rootReqPackage, $rootAnotherPackage]);
+        $this->createComposerLock([$rootReqPackage, $rootAnotherPackage]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/req'], '--no-audit' => true, '--no-interaction' => true]));
+        self::assertEquals(['root/another' => '1.*'], (new JsonFile('./composer.json'))->read()['require']);
+        self::assertEmpty((new JsonFile('./composer.json'))->read()['config']);
+    }
+
+    public function testRemoveAllowedPluginPackageWithOtherAllowedPlugins(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0', 'type' => 'metapackage'],
+                        ['name' => 'root/another', 'version' => '1.0.0', 'type' => 'metapackage']
+                    ],
+                ],
+            ],
+            'require' => [
+                'root/req' => '1.*',
+                'root/another' => '1.*',
+            ],
+            'config' => [
+                'allow-plugins' => [
+                    'root/another' => true,
+                    'root/req' => true,
+                ],
+            ],
+        ]);
+        $rootReqPackage = self::getPackage('root/req');
+        $rootAnotherPackage = self::getPackage('root/another');
+        // Set as a metapackage so that we can do the whole post-remove update & install process without Composer trying to download them (DownloadManager::getDownloaderForPackage).
+        $rootReqPackage->setType('metapackage');
+        $rootAnotherPackage->setType('metapackage');
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/req'], '--no-audit' => true, '--no-interaction' => true]));
+        self::assertEquals(['root/another' => '1.*'], (new JsonFile('./composer.json'))->read()['require']);
+        self::assertEquals(['allow-plugins' => ['root/another' => true]], (new JsonFile('./composer.json'))->read()['config']);
+    }
+
+    public function testRemovePackagesByVendor(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0'],
+                        ['name' => 'root/another', 'version' => '1.0.0'],
+                        ['name' => 'another/req', 'version' => '1.0.0'],
+                    ],
+                ],
+            ],
+            'require' => [
+                'root/req' => '1.*',
+                'root/another' => '1.*',
+                'another/req' => '1.*',
+            ],
+        ]);
+        $rootReqPackage = self::getPackage('root/req');
+        $rootAnotherPackage = self::getPackage('root/another');
+        $anotherReqPackage = self::getPackage('another/req');
+
+        $this->createInstalledJson([$rootReqPackage, $rootAnotherPackage, $anotherReqPackage]);
+        $this->createComposerLock([$rootReqPackage, $rootAnotherPackage, $anotherReqPackage]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/*'], '--no-install' => true, '--no-audit' => true, '--no-interaction' => true]));
+        self::assertStringStartsWith('./composer.json has been updated', trim($appTester->getDisplay(true)));
+        self::assertStringContainsString('Running composer update root/*', $appTester->getDisplay(true));
+        self::assertStringContainsString('- Removing root/another (1.0.0)', $appTester->getDisplay(true));
+        self::assertStringContainsString('- Removing root/req (1.0.0)', $appTester->getDisplay(true));
+        self::assertStringContainsString('Writing lock file', $appTester->getDisplay(true));
+        self::assertEquals(['another/req' => '1.*'], (new JsonFile('./composer.json'))->read()['require']);
+        self::assertEquals([['name' => 'another/req', 'version' => '1.0.0', 'type' => 'library']], (new JsonFile('./composer.lock'))->read()['packages']);
+    }
+
+    public function testRemovePackagesByVendorWithDryRun(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0'],
+                        ['name' => 'root/another', 'version' => '1.0.0'],
+                        ['name' => 'another/req', 'version' => '1.0.0'],
+                    ],
+                ],
+            ],
+            'require' => [
+                'root/req' => '1.*',
+                'root/another' => '1.*',
+                'another/req' => '1.*',
+            ],
+        ]);
+        $rootReqPackage = self::getPackage('root/req');
+        $rootAnotherPackage = self::getPackage('root/another');
+        $anotherReqPackage = self::getPackage('another/req');
+
+        $this->createInstalledJson([$rootReqPackage, $rootAnotherPackage, $anotherReqPackage]);
+        $this->createComposerLock([$rootReqPackage, $rootAnotherPackage, $anotherReqPackage]);
+
+        $appTester = $this->getApplicationTester();
+        $appTester->run(['command' => 'remove', 'packages' => ['root/*'], '--dry-run' => true, '--no-install' => true, '--no-audit' => true, '--no-interaction' => true]);
+        self::assertEquals(Command::SUCCESS, $appTester->getStatusCode());
+        self::assertSame("./composer.json has been updated
+Running composer update root/*
+Loading composer repositories with package information
+Updating dependencies
+Lock file operations: 0 installs, 0 updates, 2 removals
+  - Removing root/another (1.0.0)
+  - Removing root/req (1.0.0)", trim($appTester->getDisplay(true)));
+        self::assertStringNotContainsString('Writing lock file', $appTester->getDisplay(true));
+        self::assertEquals(['root/req' => '1.*', 'root/another' => '1.*', 'another/req' => '1.*'], (new JsonFile('./composer.json'))->read()['require']);
+        self::assertEquals([['name' => 'another/req', 'version' => '1.0.0', 'type' => 'library'], ['name' => 'root/another', 'version' => '1.0.0', 'type' => 'library'], ['name' => 'root/req', 'version' => '1.0.0', 'type' => 'library']], (new JsonFile('./composer.lock'))->read()['packages']);
+    }
+
+    public function testWarningWhenRemovingPackagesByVendorFromWrongType(): void
+    {
+        $this->initTempComposer([
+            'require' => [
+                'root/req' => '1.*',
+                'root/another' => '1.*',
+                'another/req' => '1.*',
+            ],
+        ]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/*'], '--dev' => true, '--no-interaction' => true, '--no-update' => true]));
+        self::assertSame("<warning>root/req could not be found in require-dev but it is present in require</warning>
+<warning>root/another could not be found in require-dev but it is present in require</warning>
+./composer.json has been updated", trim($appTester->getDisplay(true)));
+        self::assertEquals(['require' => ['root/req' => '1.*', 'root/another' => '1.*', 'another/req' => '1.*']], (new JsonFile('./composer.json'))->read());
+    }
+
+    public function testPackageStillPresentErrorWhenNoInstallFlagUsed(): void
+    {
+        $this->initTempComposer([
+            'require' => [
+                'root/req' => '1.*',
+            ],
+        ]);
+        $rootReqPackage = self::getPackage('root/req');
+
+        $this->createInstalledJson([$rootReqPackage]);
+        $this->createComposerLock([$rootReqPackage]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::INVALID, $appTester->run(['command' => 'remove', 'packages' => ['root/req'], '--no-install' => true, '--no-audit' => true, '--no-interaction' => true]));
+        self::assertStringContainsString('./composer.json has been updated', $appTester->getDisplay(true));
+        self::assertStringContainsString('Lock file operations: 0 installs, 0 updates, 1 removal', $appTester->getDisplay(true));
+        self::assertStringContainsString('- Removing root/req (1.0.0)', $appTester->getDisplay(true));
+        self::assertStringContainsString('Writing lock file', $appTester->getDisplay(true));
+        self::assertStringContainsString('Removal failed, root/req is still present, it may be required by another package. See `composer why root/req`', $appTester->getDisplay(true));
+        self::assertEmpty((new JsonFile('./composer.json'))->read());
+        self::assertEmpty((new JsonFile('./composer.lock'))->read()['packages']);
+        self::assertEquals([['name' => 'root/req', 'version' => '1.0.0', 'version_normalized' => '1.0.0.0', 'type' => 'library', 'install-path' => '../root/req']], (new JsonFile('./vendor/composer/installed.json'))->read()['packages']);
+    }
+
+    /**
+     * @dataProvider provideInheritedDependenciesUpdateFlag
+     */
+    public function testUpdateInheritedDependenciesFlagIsPassedToPostRemoveInstaller(string $installFlagName, string $expectedComposerUpdateCommand): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'root/req', 'version' => '1.0.0', 'type' => 'metapackage'],
+                    ],
+                ],
+            ],
+            'require' => [
+                'root/req' => '1.*',
+            ],
+        ]);
+        $rootReqPackage = self::getPackage('root/req');
+        $rootReqPackage->setType('metapackage');
+
+        $this->createInstalledJson([$rootReqPackage]);
+        $this->createComposerLock([$rootReqPackage]);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'remove', 'packages' => ['root/req'], $installFlagName => true, '--no-audit' => true, '--no-interaction' => true]));
+        self::assertStringContainsString('./composer.json has been updated', $appTester->getDisplay(true));
+        self::assertStringContainsString($expectedComposerUpdateCommand, $appTester->getDisplay(true));
+        self::assertStringContainsString('Package operations: 0 installs, 0 updates, 1 removal', $appTester->getDisplay(true));
+        self::assertStringContainsString('- Removing root/req (1.0.0)', $appTester->getDisplay(true));
+        self::assertStringContainsString('Writing lock file', $appTester->getDisplay(true));
+        self::assertStringContainsString('Lock file operations: 0 installs, 0 updates, 1 removal', $appTester->getDisplay(true));
+        self::assertEmpty((new JsonFile('./composer.lock'))->read()['packages']);
+    }
+
+    public static function provideInheritedDependenciesUpdateFlag(): \Generator
+    {
+        yield 'update with all dependencies' => [
+            '--update-with-all-dependencies',
+            'Running composer update root/req --with-all-dependencies',
+        ];
+
+        yield 'with all dependencies' => [
+            '--with-all-dependencies',
+            'Running composer update root/req --with-all-dependencies',
+        ];
+
+        yield 'no update with dependencies' => [
+            '--no-update-with-dependencies',
+            'Running composer update root/req --with-dependencies',
+        ];
+    }
+}
diff --git a/tests/Composer/Test/Command/SuggestsCommandTest.php b/tests/Composer/Test/Command/SuggestsCommandTest.php
new file mode 100644
index 000000000..217f41157
--- /dev/null
+++ b/tests/Composer/Test/Command/SuggestsCommandTest.php
@@ -0,0 +1,489 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Test\Command;
+
+use Composer\Package\CompletePackage;
+use Composer\Package\Link;
+use Composer\Test\TestCase;
+use Symfony\Component\Console\Command\Command;
+
+class SuggestsCommandTest extends TestCase
+{
+    public function testInstalledPackagesWithNoSuggestions(): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'vendor1/package1', 'version' => '1.0.0'],
+                        ['name' => 'vendor2/package2', 'version' => '1.0.0'],
+                    ],
+                ],
+            ],
+            'require' => [
+                'vendor1/package1' => '1.*',
+                'vendor2/package2' => '1.*',
+            ],
+        ]);
+
+        $packages = [
+            self::getPackage('vendor1/package1'),
+            self::getPackage('vendor2/package2'),
+        ];
+
+        $this->createInstalledJson($packages);
+        $this->createComposerLock($packages);
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(['command' => 'suggest']));
+        self::assertEmpty($appTester->getDisplay(true));
+    }
+
+    /**
+     * @dataProvider provideSuggest
+     * @param array<string, bool|string|array<int, string>> $command
+     */
+    public function testSuggest(bool $hasLockFile, array $command, string $expected): void
+    {
+        $this->initTempComposer([
+            'repositories' => [
+                'packages' => [
+                    'type' => 'package',
+                    'package' => [
+                        ['name' => 'vendor1/package1', 'version' => '1.0.0', 'suggests' => ['vendor3/suggested' => 'helpful for vendor1/package1'], 'require' => ['vendor6/package6' => '^1.0'], 'require-dev' => ['vendor3/suggested' => '^1.0', 'vendor4/dev-suggested' => '^1.0']],
+                        ['name' => 'vendor2/package2', 'version' => '1.0.0', 'suggests' => ['vendor4/dev-suggested' => 'helpful for vendor2/package2'], 'require' => ['vendor5/dev-package' => '^1.0']],
+                        ['name' => 'vendor5/dev-package', 'version' => '1.0.0', 'suggests' => ['vendor8/dev-transitive' => 'helpful for vendor5/dev-package'], 'require-dev' => ['vendor8/dev-transitive' => '^1.0']],
+                        ['name' => 'vendor6/package6', 'version' => '1.0.0', 'suggests' => ['vendor7/transitive' => 'helpful for vendor6/package6']],
+                    ],
+                ],
+            ],
+            'require' => ['vendor1/package1' => '^1'],
+            'require-dev' => ['vendor2/package2' => '^1'],
+        ]);
+
+        $packages = [
+            self::getPackageWithSuggestAndRequires(
+                'vendor1/package1',
+                '1.0.0',
+                [
+                    'vendor3/suggested' => 'helpful for vendor1/package1',
+                ],
+                [
+                    'vendor6/package6' => new Link('vendor1/package1', 'vendor6/package6', self::getVersionConstraint('>=', '1.0'), Link::TYPE_REQUIRE, '^1.0'),
+                ],
+                [
+                    'vendor4/dev-suggested' => new Link('vendor1/package1', 'vendor4/dev-suggested', self::getVersionConstraint('>=', '1.0'), Link::TYPE_DEV_REQUIRE, '^1.0'),
+                    'vendor3/suggested' => new Link('vendor1/package1', 'vendor3/suggested', self::getVersionConstraint('>=', '1.0'), Link::TYPE_DEV_REQUIRE, '^1.0'),
+                ]
+            ),
+            self::getPackageWithSuggestAndRequires(
+                'vendor6/package6',
+                '1.0.0',
+                [
+                    'vendor7/transitive' => 'helpful for vendor6/package6',
+                ]
+            ),
+        ];
+        $devPackages = [
+            self::getPackageWithSuggestAndRequires(
+                'vendor2/package2',
+                '1.0.0',
+                [
+                    'vendor4/dev-suggested' => 'helpful for vendor2/package2',
+                ],
+                [
+                    'vendor5/dev-package' => new Link('vendor2/package2', 'vendor5/dev-package', self::getVersionConstraint('>=', '1.0'), Link::TYPE_REQUIRE, '^1.0'),
+                ]
+            ),
+            self::getPackageWithSuggestAndRequires(
+                'vendor5/dev-package',
+                '1.0.0',
+                [
+                    'vendor8/dev-transitive' => 'helpful for vendor5/dev-package',
+                ],
+                [],
+                [
+                    'vendor8/dev-transitive' => new Link('vendor5/dev-package', 'vendor8/dev-transitive', self::getVersionConstraint('>=', '1.0'), Link::TYPE_DEV_REQUIRE, '^1.0'),
+                ]
+            )
+        ];
+
+        $this->createInstalledJson($packages, $devPackages);
+        if ($hasLockFile) {
+            $this->createComposerLock($packages, $devPackages);
+        }
+
+        $appTester = $this->getApplicationTester();
+        self::assertEquals(Command::SUCCESS, $appTester->run(array_merge(['command' => 'suggest'], $command)));
+        self::assertSame(trim($expected), trim($appTester->getDisplay(true)));
+    }
+
+    public function provideSuggest(): \Generator
+    {
+        yield 'with lockfile, show suggested' => [
+            true,
+            [],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'without lockfile, show suggested' => [
+            false,
+            [],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'with lockfile, show suggested (excluding dev)' => [
+            true,
+            ['--no-dev' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+1 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'without lockfile, show suggested (excluding dev)' => [
+            false,
+            ['--no-dev' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'with lockfile, show all suggested' => [
+            true,
+            ['--all' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+vendor5/dev-package suggests:
+ - vendor8/dev-transitive: helpful for vendor5/dev-package
+
+vendor6/package6 suggests:
+ - vendor7/transitive: helpful for vendor6/package6'
+        ];
+
+        yield 'without lockfile, show all suggested' => [
+            false,
+            ['--all' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+vendor5/dev-package suggests:
+ - vendor8/dev-transitive: helpful for vendor5/dev-package
+
+vendor6/package6 suggests:
+ - vendor7/transitive: helpful for vendor6/package6'
+        ];
+
+        yield 'with lockfile, show all suggested (excluding dev)' => [
+            true,
+            ['--all' => true, '--no-dev' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor6/package6 suggests:
+ - vendor7/transitive: helpful for vendor6/package6'
+        ];
+
+        yield 'without lockfile, show all suggested (excluding dev)' => [
+            false,
+            ['--all' => true, '--no-dev' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+vendor5/dev-package suggests:
+ - vendor8/dev-transitive: helpful for vendor5/dev-package
+
+vendor6/package6 suggests:
+ - vendor7/transitive: helpful for vendor6/package6'
+        ];
+
+        yield 'with lockfile, show suggested grouped by package' => [
+            true,
+            ['--by-package' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'without lockfile, show suggested grouped by package' => [
+            false,
+            ['--by-package' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'with lockfile, show suggested grouped by package (excluding dev)' => [
+            true,
+            ['--by-package' => true, '--no-dev' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+1 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'without lockfile, show suggested grouped by package (excluding dev)' => [
+            false,
+            ['--by-package' => true, '--no-dev' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'with lockfile, show suggested grouped by suggestion' => [
+            true,
+            ['--by-suggestion' => true],
+            'vendor3/suggested is suggested by:
+ - vendor1/package1: helpful for vendor1/package1
+
+vendor4/dev-suggested is suggested by:
+ - vendor2/package2: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'without lockfile, show suggested grouped by suggestion' => [
+            false,
+            ['--by-suggestion' => true],
+            'vendor3/suggested is suggested by:
+ - vendor1/package1: helpful for vendor1/package1
+
+vendor4/dev-suggested is suggested by:
+ - vendor2/package2: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'with lockfile, show suggested grouped by suggestion (excluding dev)' => [
+            true,
+            ['--by-suggestion' => true, '--no-dev' => true],
+            'vendor3/suggested is suggested by:
+ - vendor1/package1: helpful for vendor1/package1
+
+1 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'without lockfile, show suggested grouped by suggestion (excluding dev)' => [
+            false,
+            ['--by-suggestion' => true, '--no-dev' => true],
+            'vendor3/suggested is suggested by:
+ - vendor1/package1: helpful for vendor1/package1
+
+vendor4/dev-suggested is suggested by:
+ - vendor2/package2: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'with lockfile, show suggested grouped by package and suggestion' => [
+            true,
+            ['--by-package' => true, '--by-suggestion' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+------------------------------------------------------------------------------
+vendor3/suggested is suggested by:
+ - vendor1/package1: helpful for vendor1/package1
+
+vendor4/dev-suggested is suggested by:
+ - vendor2/package2: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'without lockfile, show suggested grouped by package and suggestion' => [
+            false,
+            ['--by-package' => true, '--by-suggestion' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+------------------------------------------------------------------------------
+vendor3/suggested is suggested by:
+ - vendor1/package1: helpful for vendor1/package1
+
+vendor4/dev-suggested is suggested by:
+ - vendor2/package2: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'with lockfile, show suggested grouped by package and suggestion (excluding dev)' => [
+            true,
+            ['--by-package' => true, '--by-suggestion' => true, '--no-dev' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+------------------------------------------------------------------------------
+vendor3/suggested is suggested by:
+ - vendor1/package1: helpful for vendor1/package1
+
+1 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'without lockfile, show suggested grouped by package and suggestion (excluding dev)' => [
+            false,
+            ['--by-package' => true, '--by-suggestion' => true, '--no-dev' => true],
+            'vendor1/package1 suggests:
+ - vendor3/suggested: helpful for vendor1/package1
+
+vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2
+
+------------------------------------------------------------------------------
+vendor3/suggested is suggested by:
+ - vendor1/package1: helpful for vendor1/package1
+
+vendor4/dev-suggested is suggested by:
+ - vendor2/package2: helpful for vendor2/package2
+
+2 additional suggestions by transitive dependencies can be shown with --all'
+        ];
+
+        yield 'with lockfile, show suggested for package' => [
+            true,
+            ['packages' => ['vendor2/package2']],
+            'vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2'
+        ];
+
+        yield 'without lockfile, show suggested for package' => [
+            false,
+            ['packages' => ['vendor2/package2']],
+            'vendor2/package2 suggests:
+ - vendor4/dev-suggested: helpful for vendor2/package2'
+        ];
+
+        yield 'with lockfile, list suggested' => [
+            true,
+            ['--list' => true],
+            'vendor3/suggested
+vendor4/dev-suggested',
+        ];
+
+        yield 'without lockfile, list suggested' => [
+            false,
+            ['--list' => true],
+            'vendor3/suggested
+vendor4/dev-suggested',
+        ];
+
+        yield 'with lockfile, list suggested with no transitive or no-dev dependencies' => [
+            true,
+            ['--list' => true, '--no-dev' => true],
+            'vendor3/suggested',
+        ];
+
+        yield 'without lockfile, list suggested with no transitive or no-dev dependencies' => [
+            false,
+            ['--list' => true, '--no-dev' => true],
+            'vendor3/suggested
+vendor4/dev-suggested',
+        ];
+
+        yield 'with lockfile, list suggested with all dependencies including transitive and dev dependencies' => [
+            true,
+            ['--list' => true, '--all' => true],
+            'vendor3/suggested
+vendor4/dev-suggested
+vendor7/transitive
+vendor8/dev-transitive',
+        ];
+
+        yield 'without lockfile, list suggested with all dependencies including transitive and dev dependencies' => [
+            false,
+            ['--list' => true, '--all' => true],
+            'vendor3/suggested
+vendor4/dev-suggested
+vendor7/transitive
+vendor8/dev-transitive',
+        ];
+
+        yield 'with lockfile, list all suggested (excluding dev)' => [
+            true,
+            ['--list' => true, '--all' => true, '--no-dev' => true],
+            'vendor3/suggested
+vendor7/transitive',
+        ];
+
+        yield 'without lockfile, list all suggested (excluding dev)' => [
+            false,
+            ['--list' => true, '--all' => true, '--no-dev' => true],
+            'vendor3/suggested
+vendor4/dev-suggested
+vendor7/transitive
+vendor8/dev-transitive',
+        ];
+    }
+
+    /**
+     * @param array<string, string> $suggests
+     * @param array<string, Link> $requires
+     * @param array<string, Link> $requireDevs
+     */
+    private function getPackageWithSuggestAndRequires(string $name = 'dummy/pkg', string $version = '1.0.0', array $suggests = [], array $requires = [], array $requireDevs = []): CompletePackage
+    {
+        $normVersion = self::getVersionParser()->normalize($version);
+
+        $pkg = new CompletePackage($name, $normVersion, $version);
+        $pkg->setSuggests($suggests);
+        $pkg->setRequires($requires);
+        $pkg->setDevRequires($requireDevs);
+
+        return $pkg;
+    }
+}
diff --git a/tests/complete.phpunit.xml b/tests/complete.phpunit.xml
index b30398e96..e5e4fe0f1 100644
--- a/tests/complete.phpunit.xml
+++ b/tests/complete.phpunit.xml
@@ -35,6 +35,7 @@
         </include>
         <exclude>
             <file>../src/Composer/Autoload/ClassLoader.php</file>
+            <directory>../src/Composer/PHPStan/</directory>
         </exclude>
     </coverage>
 </phpunit>