fix: Update composer.json start script target folder during migrations

src/CLI/CLI.php

@@ -364,7 +364,7 @@ public function isDefined(string $arg): bool
 	/**
 	 * Creates pretty json
 	 */
-	public function json(array $data = []): string
+	public function json(array|object $data = []): string
 	{
 		return json_encode($data, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
 	}

src/CLI/Commands/Migrate/To/PublicFolder.php

@@ -8,6 +8,7 @@
 use Kirby\CLI\Command;
 use Kirby\Filesystem\Dir;
 use Kirby\Filesystem\F;
+use stdClass;
 
 class PublicFolder extends Command
 {
@@ -37,6 +38,7 @@ public static function command(CLI $cli): void
 
 		static::makeIndexPHP($cli, $publicDir);
 		static::removeOldIndexPHP($cli);
+		static::updateComposerConfig($cli);
 
 		$cli->br();
 		$cli->success('Migrated to a public folder setup');
@@ -49,6 +51,15 @@ protected static function confirmMigration(CLI $cli): void
 		$cli->br();
 	}
 
+	/**
+	 * The document root that the built-in server has to
+	 * serve after the migration. Null if there is none.
+	 */
+	protected static function documentRoot(CLI $cli): string|null
+	{
+		return basename(static::publicDir($cli->dir()));
+	}
+
 	protected static function makeIndexPHP(CLI $cli, string $publicDir)
 	{
 		$template = $cli->root('commands.core') . '/migrate/to/_templates/index.public.simple.php';
@@ -171,4 +182,130 @@ protected static function removeOldIndexPHP(CLI $cli): void
 		}
 	}
 
+	/**
+	 * Points the start script in the composer.json
+	 * at the document root of the new setup
+	 */
+	protected static function updateComposerConfig(CLI $cli): void
+	{
+		$file = $cli->dir() . '/composer.json';
+
+		if (is_file($file) === false) {
+			return;
+		}
+
+		$contents = F::read($file);
+
+		if (is_string($contents) === false) {
+			$cli->out('🚨 The composer.json could not be read');
+			return;
+		}
+
+		// decoding into objects keeps empty objects, like an
+		// `"extra": {}`, from turning into arrays when writing back
+		$composer = json_decode($contents);
+
+		if ($composer instanceof stdClass === false) {
+			$cli->out('🚨 The composer.json could not be parsed');
+			return;
+		}
+
+		$start = $composer->scripts->start ?? null;
+
+		if ($start === null) {
+			return;
+		}
+
+		// the start script can be a single command or a list of commands
+		$commands = is_string($start) === true ? [$start] : $start;
+
+		if (is_array($commands) === false) {
+			return;
+		}
+
+		$root    = static::documentRoot($cli);
+		$server  = false;
+		$updated = false;
+
+		foreach ($commands as $key => $command) {
+			if (is_string($command) === false) {
+				continue;
+			}
+
+			$new = static::updateStartCommand($command, $root);
+
+			// the command does not start a server
+			if ($new === null) {
+				continue;
+			}
+
+			$server = true;
+
+			if ($new !== $command) {
+				$commands[$key] = $new;
+				$updated        = true;
+			}
+		}
+
+		if ($server === false) {
+			$cli->out('🚨 The start script in the composer.json could not be updated. Please set the document root manually.');
+			return;
+		}
+
+		// the start script already serves the right document root
+		if ($updated === false) {
+			return;
+		}
+
+		$composer->scripts->start = is_string($start) === true ? $commands[0] : $commands;
+
+		$json = $cli->json($composer);
+
+		// keep the trailing newline of the original file
+		if (str_ends_with($contents, "\n") === true) {
+			$json .= "\n";
+		}
+
+		if (F::write($file, $json) === true) {
+			$cli->out('✅ The composer.json has been updated');
+		} else {
+			$cli->out('🚨 The composer.json could not be updated');
+		}
+	}
+
+	/**
+	 * Sets the document root of a command that starts the
+	 * built-in server, or removes it if there is no document
+	 * root. Returns null if the command starts no server.
+	 */
+	protected static function updateStartCommand(
+		string $command,
+		string|null $root
+	): string|null {
+		$parts = preg_split('!\s+!', trim($command)) ?: [];
+
+		// only the built-in server takes a document root
+		if (in_array('-S', $parts, true) === false) {
+			return null;
+		}
+
+		// remove the current document root
+		$target = array_search('-t', $parts, true);
+
+		if ($target !== false) {
+			array_splice($parts, $target, 2);
+		}
+
+		// add the new document root right after the host and port
+		if ($root !== null) {
+			$server = array_search('-S', $parts, true);
+
+			if ($server !== false) {
+				array_splice($parts, $server + 2, 0, ['-t', $root]);
+			}
+		}
+
+		return implode(' ', $parts);
+	}
+
 }

src/CLI/Commands/Migrate/To/RootFolder.php

@@ -42,11 +42,21 @@ public static function command(CLI $cli): void
 
 		static::makeIndexPHP($cli, $dir);
 		static::removePublicDir($cli, $publicDir);
+		static::updateComposerConfig($cli);
 
 		$cli->br();
 		$cli->success('Migrated to a root folder setup');
 	}
 
+	/**
+	 * A root folder setup is served from the project
+	 * root, so the start script needs no document root
+	 */
+	protected static function documentRoot(CLI $cli): string|null
+	{
+		return null;
+	}
+
 	protected static function makeIndexPHP(CLI $cli, string $dir)
 	{
 		$template = $cli->root('commands.core') . '/migrate/to/_templates/index.root.simple.php';

tests/CLI/Commands/Migrate/To/PublicFolderProxy.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Kirby\CLI\Commands\Migrate\To;
+
+use Kirby\CLI\CLI;
+
+/**
+ * Opens up the protected migration helpers for testing
+ */
+class PublicFolderProxy extends PublicFolder
+{
+	public static function documentRoot(CLI $cli): string|null
+	{
+		return parent::documentRoot($cli);
+	}
+
+	public static function updateComposerConfig(CLI $cli): void
+	{
+		parent::updateComposerConfig($cli);
+	}
+
+	public static function updateStartCommand(
+		string $command,
+		string|null $root
+	): string|null {
+		return parent::updateStartCommand($command, $root);
+	}
+}