Replace ORCA_DRUPAL_CORE_VERSION environment variable with fixture:init --core option

config/services.yml

@@ -2,7 +2,6 @@
 parameters:
 
   # Environment variables for dynamic configuration override:
-  env(ORCA_DRUPAL_CORE_VERSION): ~
   env(ORCA_FIXTURE_DIR): "%app.fixture_dir%"
   env(ORCA_PACKAGES_CONFIG): config/packages.yml
   env(ORCA_PACKAGES_CONFIG_ALTER): ~
@@ -17,7 +16,7 @@ services:
     autowire: true
     bind:
       $drupal_core_dev_version: "%drupal_core_dev_version%"
-      $drupal_core_version: "%env(ORCA_DRUPAL_CORE_VERSION)%"
+      $drupal_core_version: "%drupal_core_dev_version%"
       $fixture_dir: "%env(ORCA_FIXTURE_DIR)%"
       $project_dir: "%kernel.project_dir%"
       $packages_config: "%env(ORCA_PACKAGES_CONFIG)%"

docs/advanced-usage.md

@@ -4,8 +4,6 @@
 
 Various aspects of ORCA's behavior can be altered at runtime through the use of environment variables. These can be set or exported in a local terminal session or [in various ways on Travis CI](https://docs.travis-ci.com/user/environment-variables/).
 
-* <a name="ORCA_DRUPAL_CORE_VERSION"></a>**`ORCA_DRUPAL_CORE_VERSION`**: Change the version of Drupal core ORCA creates test fixtures with. This can be useful for testing upgrade paths, for example. Acceptable values are any version strings Composer understands, e.g., `8.6.0`, `~8.6`, or `8.6.x-dev`.
-
 * <a name="ORCA_FIXTURE_DIR"></a>**`ORCA_FIXTURE_DIR`**: Change the directory ORCA uses for test fixtures. Acceptable values are any valid, local directory reference, e.g., `/var/www/example`, or `../example`.
 
 * <a name="ORCA_PACKAGES_CONFIG"></a>**`ORCA_PACKAGES_CONFIG`**: Completely replace the list of packages ORCA installs in fixtures and runs tests on. Acceptable values are any valid path to a YAML file relative to ORCA itself, e.g., `../example/tests/packages.yml`. See [`config/packages.yml`](../config/packages.yml) for an example and explanation of the schema.

src/Command/Fixture/FixtureInitCommand.php

@@ -85,6 +85,7 @@ protected function configure() {
       ->setHelp('Creates a BLT-based Drupal site build, includes the system under test using Composer, optionally includes all other Acquia packages, and installs Drupal.')
       ->addOption('sut', NULL, InputOption::VALUE_REQUIRED, 'The system under test (SUT) in the form of its package name, e.g., "drupal/example"')
       ->addOption('sut-only', NULL, InputOption::VALUE_NONE, 'Add only the system under test (SUT). Omit all other non-required Acquia packages')
+      ->addOption('core', NULL, InputOption::VALUE_REQUIRED, 'Change the version of Drupal core installed, e.g., "8.6.0", "~8.6", or "8.6.x-dev"')
       ->addOption('dev', NULL, InputOption::VALUE_NONE, 'Use dev (HEAD) branches instead of stable releases of Drupal core and Acquia packages')
       ->addOption('force', 'f', InputOption::VALUE_NONE, 'If the fixture already exists, remove it first without confirmation')
       ->addOption('profile', NULL, InputOption::VALUE_REQUIRED, 'The Drupal installation profile to use, e.g., "lightning"', self::DEFAULT_PROFILE)
@@ -119,6 +120,7 @@ public function execute(InputInterface $input, OutputInterface $output): int {
     $this->setSut($sut);
     $this->setSutOnly($sut_only);
     $this->setDev($input->getOption('dev'));
+    $this->setCore($input->getOption('core'));
     $this->setProfile($input->getOption('profile'));
     $this->setSqlite($input->getOption('no-sqlite'));
 
@@ -198,6 +200,18 @@ private function setDev($dev): void {
     }
   }
 
+  /**
+   * Sets the Drupal core version.
+   *
+   * @param string|string[]|bool|null $version
+   *   The version string.
+   */
+  private function setCore($version): void {
+    if ($version) {
+      $this->fixtureCreator->setCoreVersion($version);
+    }
+  }
+
   /**
    * Sets the installation profile.
    *

src/Fixture/FixtureCreator.php

@@ -168,6 +168,16 @@ public function create(): void {
     $this->createAndCheckoutBackupTag();
   }
 
+  /**
+   * Sets the Drupal core version to install.
+   *
+   * @param string $version
+   *   The version string, e.g., "8.6.0".
+   */
+  public function setCoreVersion(string $version): void {
+    $this->drupalCoreVersion = $version;
+  }
+
   /**
    * Sets the dev flag.
    *

tests/Command/Fixture/FixtureInitCommandTest.php

@@ -21,6 +21,8 @@
  */
 class FixtureInitCommandTest extends CommandTestBase {
 
+  private const DRUPAL_CORE_VERSION = '8.6.0';
+
   protected function setUp() {
     $this->fixtureCreator = $this->prophesize(FixtureCreator::class);
     $this->fixtureRemover = $this->prophesize(FixtureRemover::class);
@@ -56,6 +58,9 @@ public function testCommand($fixture_exists, $args, $methods_called, $exception,
     $this->fixtureCreator
       ->setDev(TRUE)
       ->shouldBeCalledTimes((int) in_array('setDev', $methods_called));
+    $this->fixtureCreator
+      ->setCoreVersion(self::DRUPAL_CORE_VERSION)
+      ->shouldBeCalledTimes((int) in_array('setCoreVersion', $methods_called));
     $this->fixtureCreator
       ->setSqlite(FALSE)
       ->shouldBeCalledTimes((int) in_array('setSqlite', $methods_called));
@@ -86,6 +91,7 @@ public function providerCommand() {
       [FALSE, ['--sut' => self::INVALID_PACKAGE], ['PackageManager::exists'], 0, StatusCodes::ERROR, sprintf("Error: Invalid value for \"--sut\" option: \"%s\".\n", self::INVALID_PACKAGE)],
       [FALSE, ['--sut' => self::VALID_PACKAGE], ['PackageManager::exists', 'Fixture::exists', 'create', 'setSut'], 0, StatusCodes::OK, ''],
       [FALSE, ['--sut' => self::VALID_PACKAGE, '--sut-only' => TRUE], ['PackageManager::exists', 'Fixture::exists', 'create', 'setSut', 'setSutOnly'], 0, StatusCodes::OK, ''],
+      [FALSE, ['--core' => self::DRUPAL_CORE_VERSION], ['Fixture::exists', 'setCoreVersion', 'create'], 0, StatusCodes::OK, ''],
       [FALSE, ['--dev' => TRUE], ['Fixture::exists', 'setDev', 'create'], 0, StatusCodes::OK, ''],
       [FALSE, ['--no-sqlite' => TRUE], ['Fixture::exists', 'setSqlite', 'create'], 0, StatusCodes::OK, ''],
       [FALSE, ['--profile' => 'lightning'], ['Fixture::exists', 'setProfile', 'create'], 0, StatusCodes::OK, ''],