Task: #53687 Refactor CLI input validation into option validators, add validator coverage, and refactor cfg CLI tests

bin/cfg

@@ -22,40 +22,6 @@ foreach ($autoloadFiles as $autoloadFile) {
 	}
 }
 
-function readJsonInputFile(string $path): array
-{
-	if (!is_readable($path))
-	{
-		throw new \RuntimeException("Input file is not readable: $path");
-	}
-
-	$content = file_get_contents($path);
-	if ($content === false)
-	{
-		throw new \RuntimeException("Can not read input file: $path");
-	}
-
-	try
-	{
-		$data = json_decode($content, true, 512, JSON_THROW_ON_ERROR);
-	}
-	catch (\JsonException $ex)
-	{
-		throw new \RuntimeException(sprintf(
-			'Input JSON is invalid (%s): %s',
-			(string)$ex->getCode(),
-			$ex->getMessage()
-		));
-	}
-
-	if (!is_array($data))
-	{
-		throw new \RuntimeException('Input JSON must decode to an object/array');
-	}
-
-	return $data;
-}
-
 function verboseLog(bool $enabled, string $message): void
 {
 	if ($enabled) fwrite(STDERR, "[verbose] $message".PHP_EOL);
@@ -82,6 +48,46 @@ $collection = (new Input\InputCollection())
 	->add( Input\InputTypeFactory::build('LongOption')->name('in')->short('i') // {{{
 			->flags(AbstractInputType::FLAG_OPTIONAL | Input\AbstractInputType::FLAG_VALUE_REQUIRED)
 			->description('Path to a JSON data file to read (for write)')
+			->validator(new Input\Validator(
+				function (AbstractInputType $input, AbstractInputHandler $context)
+				{
+					$path = $context->find('in');
+					if ($path === null || $path === '') {
+						return null;
+					}
+
+					if (!is_readable($path))
+					{
+						throw new \Exception("Input file is not readable: $path");
+					}
+
+					$content = file_get_contents($path);
+					if ($content === false)
+					{
+						throw new \Exception("Can not read input file: $path");
+					}
+
+					try
+					{
+						$data = json_decode($content, true, 512, JSON_THROW_ON_ERROR);
+					}
+					catch (\JsonException $ex)
+					{
+						throw new \Exception(sprintf(
+							'Input JSON is invalid (%s): %s',
+							(string)$ex->getCode(),
+							$ex->getMessage()
+						));
+					}
+
+					if (!is_array($data))
+					{
+						throw new \Exception('Input JSON must decode to an object/array');
+					}
+
+					return $data;
+				}
+			))
 		) // }}}
 
 	->add( Input\InputTypeFactory::build('LongOption')->name('mode')->short('m') // {{{
@@ -102,6 +108,55 @@ $collection = (new Input\InputCollection())
 	->add( Input\InputTypeFactory::build('LongOption')->name('siteDir') // {{{
 			->flags(AbstractInputType::FLAG_OPTIONAL | Input\AbstractInputType::FLAG_VALUE_REQUIRED)
 			->description('Site/instance directory below config/. Accepts owner_xyz or config/owner_xyz')
+			->validator(new Input\Validator(
+				function (AbstractInputType $input, AbstractInputHandler $context)
+				{
+					$siteInput = $context->find('siteDir');
+					if ($siteInput === null || $siteInput === false) {
+						return null;
+					}
+
+					$siteInput = trim((string)$siteInput);
+					$appPath = $context->find('appPath');
+					if (!$appPath) {
+						$appPath = getcwd().'/';
+					}
+					$appPath = rtrim($appPath, '/').'/';
+
+					// Accept both "owner_xyz" and "config/owner_xyz" and normalize to site key.
+					if (str_starts_with($siteInput, $appPath.'config/'))
+					{
+						$siteInput = substr($siteInput, strlen($appPath.'config/'));
+					}
+					elseif (str_starts_with($siteInput, 'config/'))
+					{
+						$siteInput = substr($siteInput, strlen('config/'));
+					}
+
+					$siteInput = trim($siteInput, '/');
+					if ($siteInput === '')
+					{
+						throw new \Exception('Option --siteDir is empty.');
+					}
+
+					// Block directory traversal and hidden-dot segments.
+					if (str_contains($siteInput, '..') || preg_match('~(^|/)\.(?:/|$)~', $siteInput))
+					{
+						throw new \Exception("Invalid directory in --siteDir: '$siteInput'.");
+					}
+
+					// Allow only predictable path segments for instance directories.
+					foreach (explode('/', $siteInput) as $part)
+					{
+						if ($part === '' || !preg_match('/^[A-Za-z0-9._-]+$/', $part))
+						{
+							throw new \Exception("Invalid directory name segment '$part' in --siteDir.");
+						}
+					}
+
+					return $siteInput;
+				}
+			))
 		) // }}}
 
 	->add( Input\InputTypeFactory::build('Argument')->name('action') // {{{
@@ -151,6 +206,14 @@ $collection = (new Input\InputCollection())
 				{
 					$setting = $context->find('setting');
 						$action = $context->find('action');
+						$inputPayload = $context->find('in');
+
+						if ($action === 'write')
+						{
+							if (($setting !== null && $setting !== '') && $inputPayload) {
+								throw new \Exception('Please use either SETTING or --in, not both.');
+							}
+						}
 	
 					if ($setting === null || $setting === '') {
 						return ['key' => '', 'value' => null];
@@ -274,44 +337,9 @@ if ($pkgPath = $argv->find('pkgPath')) $cfg->pkgPath(rtrim($pkgPath, '/').'/');
 
 $site = null;
 $siteFlag = 0x01;
-$siteInput = $argv->find('siteDir');
-if ($siteInput !== null && $siteInput !== false)
+$site = $argv->find('siteDir');
+if ($site !== null && $site !== false)
 {
-	$siteInput = trim((string)$siteInput);
-
-	// Accept both "owner_xyz" and "config/owner_xyz" and normalize to site key.
-	if (str_starts_with($siteInput, $appPath.'config/'))
-	{
-		$siteInput = substr($siteInput, strlen($appPath.'config/'));
-	}
-	elseif (str_starts_with($siteInput, 'config/'))
-	{
-		$siteInput = substr($siteInput, strlen('config/'));
-	}
-
-	$siteInput = trim($siteInput, '/');
-	if ($siteInput === '')
-	{
-		fwrite(STDERR, 'Option --siteDir is empty.'.PHP_EOL);
-		exit(1);
-	}
-	// Block directory traversal and hidden-dot segments.
-	if (str_contains($siteInput, '..') || preg_match('~(^|/)\.(?:/|$)~', $siteInput))
-	{
-		fwrite(STDERR, "Invalid directory in --siteDir: '$siteInput'.".PHP_EOL);
-		exit(1);
-	}
-	// Allow only predictable path segments for instance directories.
-	foreach (explode('/', $siteInput) as $part)
-	{
-		if ($part === '' || !preg_match('/^[A-Za-z0-9._-]+$/', $part))
-		{
-			fwrite(STDERR, "Invalid directory name segment '$part' in --siteDir.".PHP_EOL);
-			exit(1);
-		}
-	}
-
-	$site = $siteInput;
 		// Reuse util-settings site resolution: config/<site>/<prefix>.conf.php
 		$cfg->site($site);
 		verboseLog($verbose, "siteDir resolved to '$site'");
@@ -362,34 +390,17 @@ case 'show':
 	break;
 	
 		case 'write':
-	$inputFile = $argv->find('in');
-	// Write needs exactly one payload source:
-	// either SETTING (key=value) or --in (JSON file).
-	// This avoids ambiguous input precedence and empty writes.
-	if ($inputFile && $settings['key'] !== '')
-	{
-		fwrite(STDERR, 'Please use either SETTING or --in, not both.'.PHP_EOL);
-		exit(1);
-	}
-	if (!$inputFile && $settings['key'] === '')
+			$inputPayload = $argv->find('in');
+			if (!$inputPayload && $settings['key'] === '')
 			{
 				fwrite(STDERR, 'Nothing to write: provide SETTING or --in.'.PHP_EOL);
 				exit(1);
 			}
-
 			$path = ($settings['key'] !== '') ? explode(':', $settings['key']) : [];
-	verboseLog($verbose, 'write source: '.($inputFile ? "--in ($inputFile)" : 'SETTING'));
-	if ($inputFile)
+			verboseLog($verbose, 'write source: '.($inputPayload ? '--in' : 'SETTING'));
+		if ($inputPayload)
 		{
-		try
-		{
-			$setting2write = readJsonInputFile($inputFile);
-		}
-		catch (\Throwable $e)
-		{
-			fwrite(STDERR, $e->getMessage().PHP_EOL);
-			exit(1);
-		}
+			$setting2write = $inputPayload;
 		}
 		else
 		{
@@ -402,7 +413,7 @@ case 'write':
 		$setting2write = [array_pop($path) => $setting2write];
 	}
 
-	$writeType = ($site !== null) ? $siteFlag : null;
+    $writeType = ($site !== null && $site !== false) ? $siteFlag : null;
 	$file = $cfg->buildFileName($writeType);
 	verboseLog($verbose, "write target: $file");
 	if (is_readable($file))

tests/CfgTest.php

@@ -8,6 +8,7 @@ class CfgTest extends TestCase
 {
 	private string $tmpDir;
 
+	/* Lifecycle {{{ */
 	protected function setUp(): void
 	{
 		$this->tmpDir = rtrim(sys_get_temp_dir(), '/').'/util-settings-cfg-'.bin2hex(random_bytes(8));
@@ -24,18 +25,16 @@ class CfgTest extends TestCase
 	{
 		$this->removeDir($this->tmpDir);
 	}
+	/* }}} */
 
+	/* Write Flow {{{ */
 	public function testWriteWithoutDirectoryNameUsesLocalConfigFile(): void
 	{
-		$result = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$result = $this->runWrite([
 			'module:code="X100"',
 		]);
 
-		$this->assertSame(0, $result['code'], $result['output']);
+		$this->assertCfgSuccess($result);
 
 		$localFile = $this->tmpDir.'/config/Extension.conf.php';
 		$this->assertFileExists($localFile);
@@ -51,24 +50,17 @@ class CfgTest extends TestCase
 			"<?php return [\n\t'module' => [\n\t\t'code' => '',\n\t],\n];\n"
 		);
 
-		$result = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$result = $this->runWrite([
 			'module:code="X100"',
 		]);
 
-		$this->assertSame(0, $result['code'], $result['output']);
+		$this->assertCfgSuccess($result);
 		$this->assertFileExists($this->tmpDir.'/config/Extension.conf.php');
 	}
 
 	public function testWriteWithInputFileWritesMultipleSettings(): void
 	{
-		$inFile = $this->tmpDir.'/extension-in.json';
-		file_put_contents(
-				$inFile,
-				json_encode([
+		$inFile = $this->createJsonInputFile([
 			'module' => [
 				'code' => 'X100',
 				'label' => 'demo-module',
@@ -76,21 +68,16 @@ class CfgTest extends TestCase
 			'feature' => [
 				'endpoint' => 'https://example.invalid/v1/resource',
 			],
-				], JSON_PRETTY_PRINT)
-		);
+		]);
 
-		$result = $this->runCfg([
-			'-a',
-			$this->tmpDir,
-			'write',
-			'Extension',
+		$result = $this->runWrite([
 			'--siteDir=owner_xyz',
 			'-i',
 			$inFile,
 		]);
 
-		$this->assertSame(0, $result['code'], $result['output']);
-		$cfg = require $this->tmpDir.'/config/owner_xyz/Extension.conf.php';
+		$this->assertCfgSuccess($result);
+		$cfg = $this->loadWrittenConfig('owner_xyz');
 		$this->assertSame('X100', $cfg['module']['code']);
 		$this->assertSame('demo-module', $cfg['module']['label']);
 		$this->assertSame('https://example.invalid/v1/resource', $cfg['feature']['endpoint']);
@@ -98,68 +85,59 @@ class CfgTest extends TestCase
 
 	public function testWriteAcceptsJsonStringValueInSetting(): void
 	{
-		$result = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$result = $this->runWrite([
 			'module={"code":"X100","label":"demo-module"}',
 			'--siteDir=owner_xyz',
 		]);
 
-		$this->assertSame(0, $result['code'], $result['output']);
-		$cfg = require $this->tmpDir.'/config/owner_xyz/Extension.conf.php';
+		$this->assertCfgSuccess($result);
+		$cfg = $this->loadWrittenConfig('owner_xyz');
 		$this->assertSame('X100', $cfg['module']['code']);
 		$this->assertSame('demo-module', $cfg['module']['label']);
 	}
 
 	public function testWriteSupportsNestedPathWithColonNotation(): void
 	{
-		$result = $this->runCfg([
-			'-a',
-			$this->tmpDir,
-			'write',
-			'Extension',
+		$result = $this->runWrite([
 			'module:flags:enabled=true',
 			'--siteDir=owner_xyz',
 		]);
 
-		$this->assertSame(0, $result['code'], $result['output']);
-		$cfg = require $this->tmpDir.'/config/owner_xyz/Extension.conf.php';
+		$this->assertCfgSuccess($result);
+		$cfg = $this->loadWrittenConfig('owner_xyz');
 		$this->assertTrue($cfg['module']['flags']['enabled']);
 	}
 
-	public function testWriteWithInputFileAndSettingReturnsError(): void
+	public function testWriteCoercesSimpleStringValueToJsonString(): void
 	{
-		$inFile = $this->tmpDir.'/extension-in.json';
-		file_put_contents($inFile, json_encode(['module' => ['code' => 'X100']]));
-
-		$result = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
-				'module:code="x"',
-				'-i',
-				$inFile,
+		$result = $this->runWrite([
+			'module:code=X100',
+			'--siteDir=owner_xyz',
 		]);
 
-		$this->assertSame(1, $result['code']);
-		$this->assertStringContainsString('Please use either SETTING or --in, not both.', $result['output']);
+		$this->assertCfgSuccess($result);
+		$cfg = $this->loadWrittenConfig('owner_xyz');
+		$this->assertSame('X100', $cfg['module']['code']);
+	}
+
+	public function testWriteRejectsInvalidJsonStringValue(): void
+	{
+		$result = $this->runWrite([
+			'module={"code":',
+			'--siteDir=owner_xyz',
+		]);
+
+		$this->assertCfgFailure($result, 'The value does not appear to be a valid JSON string.');
 	}
 
 	public function testWriteWithSiteDirCreatesAndWritesSiteConfig(): void
 	{
-		$result = $this->runCfg([
-			'-a',
-			$this->tmpDir,
-			'write',
-			'Extension',
+		$result = $this->runWrite([
 			'module:code="X100"',
 			'--siteDir=owner_xyz',
 		]);
 
-		$this->assertSame(0, $result['code'], $result['output']);
+		$this->assertCfgSuccess($result);
 
 		$siteFile = $this->tmpDir.'/config/owner_xyz/Extension.conf.php';
 		$this->assertFileExists($siteFile);
@@ -171,28 +149,19 @@ class CfgTest extends TestCase
 
 	public function testWriteWithSiteDirMergesIntoExistingSiteConfig(): void
 	{
-		$firstWrite = $this->runCfg([
-			'-a',
-			$this->tmpDir,
-			'write',
-			'Extension',
+		$firstWrite = $this->runWrite([
 			'module:code="X100"',
 			'--siteDir=owner_xyz',
 		]);
-		$this->assertSame(0, $firstWrite['code'], $firstWrite['output']);
+		$this->assertCfgSuccess($firstWrite);
 
-		$secondWrite = $this->runCfg([
-			'-a',
-			$this->tmpDir,
-			'write',
-			'Extension',
+		$secondWrite = $this->runWrite([
 			'module:label="demo-module"',
 			'--siteDir=owner_xyz',
 		]);
-		$this->assertSame(0, $secondWrite['code'], $secondWrite['output']);
+		$this->assertCfgSuccess($secondWrite);
 
-		$siteFile = $this->tmpDir.'/config/owner_xyz/Extension.conf.php';
-		$cfg = require $siteFile;
+		$cfg = $this->loadWrittenConfig('owner_xyz');
 
 		$this->assertSame('X100', $cfg['module']['code']);
 		$this->assertSame('demo-module', $cfg['module']['label']);
@@ -200,56 +169,62 @@ class CfgTest extends TestCase
 
 	public function testWriteWithSiteDirUsingConfigPrefixIsNormalized(): void
 	{
-		$result = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$result = $this->runWrite([
 			'module:code="X100"',
 			'--siteDir=config/owner_xyz',
 		]);
 
-		$this->assertSame(0, $result['code'], $result['output']);
+		$this->assertCfgSuccess($result);
 		$this->assertFileExists($this->tmpDir.'/config/owner_xyz/Extension.conf.php');
 		$this->assertFileDoesNotExist($this->tmpDir.'/config/config/owner_xyz/Extension.conf.php');
 	}
 
+	public function testWriteWithSiteDirUsingAbsoluteConfigPrefixIsNormalized(): void
+	{
+		$result = $this->runWrite([
+			'module:code="X100"',
+			'--siteDir='.$this->tmpDir.'/config/owner_xyz',
+		]);
+
+		$this->assertCfgSuccess($result);
+		$this->assertFileExists($this->tmpDir.'/config/owner_xyz/Extension.conf.php');
+	}
+
+	public function testWriteWithNestedSiteDirWritesToNestedSiteConfig(): void
+	{
+		$result = $this->runWrite([
+			'module:code="X100"',
+			'--siteDir=owner_xyz/sub_a',
+		]);
+
+		$this->assertCfgSuccess($result);
+		$this->assertFileExists($this->tmpDir.'/config/owner_xyz/sub_a/Extension.conf.php');
+	}
+
 	public function testWriteWithSiteDirWritesToSiteConfig(): void
 	{
-		$result = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$result = $this->runWrite([
 			'module:code="X100"',
 			'--siteDir=owner_xyz',
 		]);
 
-		$this->assertSame(0, $result['code'], $result['output']);
+		$this->assertCfgSuccess($result);
 		$this->assertFileExists($this->tmpDir.'/config/owner_xyz/Extension.conf.php');
 	}
 
 	public function testWriteToExistingSiteConfigCreatesBackup(): void
 	{
-		$firstWrite = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$firstWrite = $this->runWrite([
 			'module:code="first"',
 			'--siteDir=owner_xyz',
 		]);
-		$this->assertSame(0, $firstWrite['code'], $firstWrite['output']);
+		$this->assertCfgSuccess($firstWrite);
 
-		$secondWrite = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$secondWrite = $this->runWrite([
 			'module:code="second"',
 			'--siteDir=owner_xyz',
 		]);
-		$this->assertSame(0, $secondWrite['code'], $secondWrite['output']);
+		$this->assertCfgSuccess($secondWrite);
 
 		$siteFile = $this->tmpDir.'/config/owner_xyz/Extension.conf.php';
 		$backupFile = $siteFile.'.bak';
@@ -260,74 +235,180 @@ class CfgTest extends TestCase
 		$this->assertSame('second', $current['module']['code']);
 		$this->assertSame('first', $backup['module']['code']);
 	}
+	/* }}} */
 
+	/* Show Flow {{{ */
 	public function testShowWithSiteReturnsSiteSpecificValue(): void
 	{
-		$this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$this->runWrite([
 			'module:code="X100"',
 			'--siteDir=owner_xyz',
 		]);
 
-		$show = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'show',
-				'Extension',
+		$show = $this->runShow([
 			'module:code',
 			'--siteDir=owner_xyz',
 		]);
 
-		$this->assertSame(0, $show['code'], $show['output']);
+		$this->assertCfgSuccess($show);
 		$this->assertStringContainsString('X100', $show['output']);
 	}
+	/* }}} */
 
-	public function testSiteDirRejectsTraversal(): void
+	/* Validation {{{ */
+	public function testInvalidActionReturnsError(): void
 	{
 		$result = $this->runCfg([
 			'-a',
 			$this->tmpDir,
-				'write',
+			'delete',
 			'Extension',
-				'module:code="X100"',
-				'--siteDir=../owner_xyz',
 		]);
 
-		$this->assertSame(1, $result['code']);
-		$this->assertStringContainsString('Invalid directory in --siteDir', $result['output']);
-	}
-
-	public function testSiteDirRejectsInvalidSegment(): void
-	{
-		$result = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
-				'module:code="X100"',
-				'--siteDir=owner xyz',
-			]);
-
-		$this->assertSame(1, $result['code']);
-		$this->assertStringContainsString("Invalid directory name segment 'owner xyz' in --siteDir.", $result['output']);
+		$this->assertCfgFailure($result, "'delete' not found");
 	}
 
 	public function testSiteDirRejectsEmptyValue(): void
 	{
-		$result = $this->runCfg([
-				'-a',
-				$this->tmpDir,
-				'write',
-				'Extension',
+		$result = $this->runWrite([
 			'module:code="X100"',
 			'--siteDir=',
 		]);
 
-		$this->assertSame(1, $result['code']);
-		$this->assertStringContainsString('a value is required for --siteDir', $result['output']);
+		$this->assertCfgFailure($result, 'a value is required for --siteDir');
+	}
+
+	/**
+	 * @dataProvider siteDirValidationDataProvider
+	 */
+	public function testSiteDirValidation(string $siteDir, string $expectedMessage): void
+	{
+		$result = $this->runWrite([
+			'module:code="X100"',
+			'--siteDir='.$siteDir,
+		]);
+
+		$this->assertCfgFailure($result, $expectedMessage);
+	}
+
+	/**
+	 * @dataProvider inputFileValidationDataProvider
+	 */
+	public function testInputFileValidation(?string $fileContents, string $pathSuffix, string $expectedMessage): void
+	{
+		$inFile = $this->tmpDir.'/'.$pathSuffix;
+		if ($fileContents !== null) {
+			file_put_contents($inFile, $fileContents);
+		}
+
+		$result = $this->runWrite([
+			'-i',
+			$inFile,
+		]);
+
+		$this->assertCfgFailure($result, $expectedMessage);
+	}
+
+	/**
+	 * @dataProvider writePayloadSourceValidationDataProvider
+	 */
+	public function testWritePayloadSourceValidation(array $extraArgs, string $expectedMessage): void
+	{
+		$inFile = $this->createJsonInputFile(['module' => ['code' => 'X100']]);
+
+		$args = array_merge(
+			[
+				'-a',
+				$this->tmpDir,
+				'write',
+				'Extension',
+			],
+			array_map(
+				fn (string $arg): string => $arg === '__INPUT_FILE__' ? $inFile : $arg,
+				$extraArgs
+			)
+		);
+
+		$result = $this->runCfg($args);
+
+		$this->assertCfgFailure($result, $expectedMessage);
+	}
+
+	public function siteDirValidationDataProvider(): array
+	{
+		return [
+			'traversal' => ['../owner_xyz', 'Invalid directory in --siteDir'],
+			'invalid segment' => ['owner xyz', "Invalid directory name segment 'owner xyz' in --siteDir."],
+			'hidden dot segment' => ['owner_xyz/./secret', "Invalid directory in --siteDir: 'owner_xyz/./secret'."],
+			'config root only' => ['config/', 'Option --siteDir is empty.'],
+		];
+	}
+
+	public function inputFileValidationDataProvider(): array
+	{
+		return [
+			'missing file' => [null, 'missing.json', 'Input file is not readable'],
+			'invalid json' => ['{"module":', 'invalid.json', 'Input JSON is invalid'],
+			'scalar json' => ['true', 'scalar.json', 'Input JSON must decode to an object/array'],
+		];
+	}
+
+	public function writePayloadSourceValidationDataProvider(): array
+	{
+		return [
+			'missing payload source' => [[], 'Nothing to write: provide SETTING or --in.'],
+			'both payload sources' => [['module:code="x"', '-i', '__INPUT_FILE__'], 'Please use either SETTING or --in, not both.'],
+		];
+	}
+	/* }}} */
+
+	/* Helpers {{{ */
+	private function runWrite(array $args): array
+	{
+		return $this->runCfg(array_merge([
+			'-a',
+			$this->tmpDir,
+			'write',
+			'Extension',
+		], $args));
+	}
+
+	private function runShow(array $args): array
+	{
+		return $this->runCfg(array_merge([
+			'-a',
+			$this->tmpDir,
+			'show',
+			'Extension',
+		], $args));
+	}
+
+	private function createJsonInputFile(array $contents, string $name = 'extension-in.json'): string
+	{
+		$path = $this->tmpDir.'/'.$name;
+		file_put_contents($path, json_encode($contents, JSON_PRETTY_PRINT));
+
+		return $path;
+	}
+
+	private function loadWrittenConfig(?string $siteDir = null): array
+	{
+		$path = $siteDir === null
+			? $this->tmpDir.'/config/Extension.conf.php'
+			: $this->tmpDir.'/config/'.$siteDir.'/Extension.conf.php';
+
+		return require $path;
+	}
+
+	private function assertCfgSuccess(array $result): void
+	{
+		$this->assertSame(0, $result['code'], $result['output']);
+	}
+
+	private function assertCfgFailure(array $result, string $message): void
+	{
+		$this->assertSame(1, $result['code'], $result['output']);
+		$this->assertStringContainsString($message, $result['output']);
 	}
 
 	private function runCfg(array $args): array
@@ -372,4 +453,5 @@ class CfgTest extends TestCase
 
 		rmdir($dir);
 	}
+	/* }}} */
 }