refactor(LoadSandbox) move debug information to exception

Since the output of `codecept_debug` will only show if the user is
running the Codeception command using the `--debug` output, I've moved
the information that will help the user debug the issue to the exception
to make sure it will always print. I've changed the wording a bit to be
more general and cover other commands (e.g. the `console` one) that will
use the LoadSandbox class and might fail like the `run` command does.
Fix test.

src/WordPress/InstallationException.php

@@ -76,8 +76,9 @@ public static function becauseWordPressMultsiteIsNotInstalled(bool $isSubdomainI
     public static function becauseCodeceptionCommandDidNotFinish(): self
     {
         return new self(
-            "Codeception `run` command did not finish properly; WordPress exited early during sandbox installation. "
-            ."A plugin, theme, or WP-CLI package may have exited before the wp_loaded action could run.",
+            "The current Codeception command did not finish properly. WordPress exited early while loading. "
+            ."A plugin, theme, or WP-CLI package may have exited before the wp_loaded action could be fired. " .
+            "If there is error output above, it may provide clues.",
             self::COMMAND_DID_NOT_FINISH_PROPERLY
         );
     }

src/WordPress/LoadSandbox.php

@@ -124,12 +124,8 @@ class_exists(InstallationException::class);
         }
 
         if ($bodyContent === 'COMMAND DID NOT FINISH PROPERLY.') {
-            // we got here from \Codeception\Subscriber\ErrorHandler::shutdownHandler()
-            codecept_debug('Codeception error: ' .$bodyContent);
-            codecept_debug(
-                'DEBUG: Something caused WordPress to exit early. If there is error output above, it may provide clues. '
-                .'(For instance, a WP-CLI package mistakenly attempting to handle the `codecept run` command.)'
-            );
+            // We got here from \Codeception\Subscriber\ErrorHandler::shutdownHandler().
+            // We'll try to provide some clues to the user by adding some debug output.
             throw InstallationException::becauseCodeceptionCommandDidNotFinish();
         }
 

tests/unit/lucatume/WPBrowser/WordPress/LoadSandboxTest.php

@@ -3,11 +3,9 @@
 
 namespace Unit\lucatume\WPBrowser\WordPress;
 
-use Codeception\Subscriber\ErrorHandler;
 use Codeception\Test\Unit;
 use Exception;
-use lucatume\WPBrowser\Process\ProcessException;
-use lucatume\WPBrowser\Process\WorkerException;
+use lucatume\WPBrowser\Tests\Traits\Fork;
 use lucatume\WPBrowser\Tests\Traits\LoopIsolation;
 use lucatume\WPBrowser\Tests\Traits\TmpFilesCleanup;
 use lucatume\WPBrowser\Traits\UopzFunctions;
@@ -363,25 +361,31 @@ public function should_handle_codeception_command_not_finished_error(): void {
  * @see \Codeception\Subscriber\ErrorHandler::shutdownHandler()
  */
 add_action('after_setup_theme', function () {
-    // Output and exit from \Codeception\Subscriber\ErrorHandler::shutdownHandler
+    // Output and exit from \Codeception\Subscriber\ErrorHandler::shutdownHandler.
     echo "\n\n\nCOMMAND DID NOT FINISH PROPERLY.\n";
     exit(125);
 });
 PHP;
 
-        if (!file_exists($installation->getMuPluginsDir())) {
-            mkdir($installation->getMuPluginsDir());
+        $muPluginsDir = $installation->getMuPluginsDir();
+        if (
+            !is_dir($muPluginsDir)
+            && !(
+                mkdir($muPluginsDir, 0755, true)
+                && is_dir($muPluginsDir)
+            )
+        ) {
+            throw new \RuntimeException('Could not create mu-plugins directory.');
+        }
+        if(!file_put_contents($muPluginsDir . '/exiting-mu-plugin.php', $exitingPluginCode)){
+            throw new \RuntimeException('Could not write exiting-mu-plugin.php.');
         }
-        file_put_contents($installation->getMuPluginsDir() . '/exiting-mu-plugin.php', $exitingPluginCode);
-
-        $this->preventExit();
 
         $this->expectException(InstallationException::class);
-        $this->expectExceptionMessageMatches('WordPress exited early during sandbox installation');
+        $this->expectExceptionMessage(InstallationException::becauseCodeceptionCommandDidNotFinish()->getMessage());
 
-        $loadSandbox = new LoadSandbox($wpRootDir, 'wordpress.test');
-
-        $this->assertInIsolation(static function () use ($loadSandbox) {
+        $this->assertInIsolation(static function () use ($wpRootDir) {
+            $loadSandbox = new LoadSandbox($wpRootDir, 'wordpress.test');
             $loadSandbox->load();
         });
     }