Harden no-cache output cleanup

docs/commands.md

@@ -15,7 +15,7 @@ Generates static HTML content from source files.
 - `--content-dir`, `-c` — path to the content directory (default: `content`). Absolute or relative to project root.
 - `--output-dir`, `-o` — path to the output directory (default: `output`). Absolute or relative to project root.
 - `--workers`, `-w` — number of parallel workers or `auto` (default: `auto`). Auto mode detects available CPU capacity inside the container, caps it at `4`, and still falls back to sequential work for small task sets.
-- `--no-cache` — disable build cache and incremental builds. Forces a full rebuild, clearing the output directory. By default, rendered HTML is cached and a build manifest tracks source file hashes for incremental builds.
+- `--no-cache` — disable build cache and incremental builds. Forces a full rebuild, clearing the output directory only when it is empty or contains YiiPress' build marker. By default, rendered HTML is cached and a build manifest tracks source file hashes for incremental builds.
 - `--drafts` — include draft entries in the build. By default, entries with `draft: true` in front matter are excluded from HTML output, feeds, and sitemap.
 - `--future` — include future-dated entries in the build. By default, entries with a date in the future are excluded from HTML output, feeds, and sitemap.
 - `--dry-run` — list all files that would be generated without writing anything. The output directory is not created or modified.

src/Console/BuildCommand.php

@@ -62,6 +62,7 @@
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\OutputInterface;
+use Yiisoft\Files\FileHelper;
 use Yiisoft\FriendlyException\FriendlyExceptionInterface;
 use Yiisoft\Yii\Console\ExitCode;
 
@@ -104,6 +105,7 @@
 final class BuildCommand extends Command
 {
     private const int MAX_AUTO_WORKERS = 4;
+    private const string BUILD_MARKER = '.yiipress-build';
 
     public function __construct(
         private readonly string $rootPath,
@@ -200,17 +202,6 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         $includeFuture = $input->getOption('future') !== false ? (bool) $input->getOption('future') : Environment::isDev();
         $dryRun = (bool) $input->getOption('dry-run');
         $noWrite = (bool) $input->getOption('no-write');
-        $buildContext = new BuildContext(
-            rootPath: $rootPath,
-            contentDir: $contentDir,
-            outputDir: $outputDir,
-            workerCount: $workerCount,
-            noCache: $noCache,
-            includeDrafts: $includeDrafts,
-            includeFuture: $includeFuture,
-            dryRun: $dryRun,
-            noWrite: $noWrite,
-        );
         $profile = new BuildProfile((bool) $input->getOption('profile'));
         $profile->start('prepare');
 
@@ -312,9 +303,6 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                 : '<info>Rendering and writing output' . $this->workerMessageSuffix($workerCount, false) . '...</info>',
             );
 
-            if (!$noWrite) {
-                $this->prepareOutputDir($outputDir);
-            }
         }
 
         if ($manifest !== null && $allSourceFiles === []) {
@@ -363,6 +351,28 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             return $exitCode;
         }
 
+        if (!$noWrite && $noCache) {
+            try {
+                $this->prepareOutputDir($outputDir);
+            } catch (RuntimeException $e) {
+                $output->writeln('<error>' . OutputFormatter::escape($e->getMessage()) . '</error>');
+                $this->writeProfile($output, $profile);
+                return ExitCode::DATAERR;
+            }
+        }
+
+        $buildContext = new BuildContext(
+            rootPath: $rootPath,
+            contentDir: $contentDir,
+            outputDir: $outputDir,
+            workerCount: $workerCount,
+            noCache: $noCache,
+            includeDrafts: $includeDrafts,
+            includeFuture: $includeFuture,
+            dryRun: $dryRun,
+            noWrite: $noWrite,
+        );
+
         $this->eventDispatcher?->dispatch(new BuildStartedEvent($buildContext, $siteConfig, $navigation, $collections, $authors));
 
         /** @var array<string, list<Entry>> $rawEntriesByCollection */
@@ -823,6 +833,10 @@ function (array $feedTask) use ($siteConfig, $outputDir, $authors, $noWrite): in
             $manifest->save();
         }
 
+        if (!$noWrite) {
+            $this->writeBuildMarker($outputDir);
+        }
+
         $this->eventDispatcher?->dispatch(new BuildFinishedEvent($buildContext, $siteConfig));
 
         $profile->stop();
@@ -1208,14 +1222,48 @@ private function dryRun(
 
     private function prepareOutputDir(string $outputDir): void
     {
+        if (is_file($outputDir)) {
+            throw new RuntimeException(sprintf('Output path "%s" exists and is not a directory.', $outputDir));
+        }
+
         if (is_dir($outputDir)) {
-            exec('rm -rf ' . escapeshellarg($outputDir));
+            if (!$this->canReplaceOutputDir($outputDir)) {
+                throw new RuntimeException(sprintf(
+                    'Refusing to clear "%s" because it is not marked as a YiiPress build output directory.',
+                    $outputDir,
+                ));
+            }
+
+            FileHelper::removeDirectory($outputDir);
         }
         if (!mkdir($outputDir, 0o755, true) && !is_dir($outputDir)) {
             throw new RuntimeException(sprintf('Directory "%s" was not created', $outputDir));
         }
     }
 
+    private function canReplaceOutputDir(string $outputDir): bool
+    {
+        if (is_file($outputDir . '/' . self::BUILD_MARKER)) {
+            return true;
+        }
+
+        return $this->isDirectoryEmpty($outputDir);
+    }
+
+    private function isDirectoryEmpty(string $directory): bool
+    {
+        $iterator = new FilesystemIterator($directory, FilesystemIterator::SKIP_DOTS);
+
+        return !$iterator->valid();
+    }
+
+    private function writeBuildMarker(string $outputDir): void
+    {
+        if (file_put_contents($outputDir . '/' . self::BUILD_MARKER, "generated-by: yiipress\n") === false) {
+            throw new RuntimeException(sprintf('Unable to write build marker in "%s".', $outputDir));
+        }
+    }
+
     private function resolvePath(string $path, string $rootPath): string
     {
         if (str_starts_with($path, '/')) {

tests/Unit/Console/BuildCommandTest.php

@@ -94,6 +94,7 @@ public function testBuildGeneratesOutputFiles(): void
         assertSame(0, $exitCode, "Build failed: $outputText");
         assertMatchesRegularExpression('/Build complete in \d+(?:\.\d+)?(?:ms|s)\. Peak memory: \d+(?:\.\d+)? MiB\./', $outputText);
         assertDirectoryExists($this->outputDir);
+        assertFileExists($this->outputDir . '/.yiipress-build');
     }
 
     public function testBuildHooksAreDispatched(): void
@@ -149,10 +150,12 @@ public function testBuildReportsInvalidSiteConfigWithoutTrace(): void
         $contentDir = $tempDir . '/content';
         $outputDir = $tempDir . '/output';
         mkdir($contentDir, 0o755, true);
+        mkdir($outputDir, 0o755, true);
         $this->tempContentDirs[] = $tempDir;
 
         file_put_contents($contentDir . '/config.yaml', "title: Broken Site\n");
         file_put_contents($contentDir . '/index.md', "---\ntitle: Home\n---\n\nHello.\n");
+        file_put_contents($outputDir . '/existing.html', 'existing output');
 
         $yii = dirname(__DIR__, 3) . '/yii';
         exec(
@@ -175,6 +178,38 @@ public function testBuildReportsInvalidSiteConfigWithoutTrace(): void
         assertStringNotContainsString('Stack trace:', $outputText);
         assertStringNotContainsString('RuntimeException:', $outputText);
         assertStringNotContainsString('#0 ', $outputText);
+        assertFileExists($outputDir . '/existing.html');
+    }
+
+    public function testNoCacheBuildRefusesToClearUnmarkedNonEmptyOutputDirectory(): void
+    {
+        $tempDir = sys_get_temp_dir() . '/yiipress-build-output-safety-test-' . uniqid();
+        $contentDir = $tempDir . '/content';
+        $outputDir = $tempDir . '/public_html';
+        mkdir($contentDir, 0o755, true);
+        mkdir($outputDir, 0o755, true);
+        $this->tempContentDirs[] = $tempDir;
+
+        file_put_contents($contentDir . '/config.yaml', "title: Safe Site\nlanguages: [en]\n");
+        file_put_contents($contentDir . '/index.md', "---\ntitle: Home\n---\n\nHello.\n");
+        file_put_contents($outputDir . '/do-not-delete.html', 'important');
+
+        $yii = dirname(__DIR__, 3) . '/yii';
+        exec(
+            $yii . ' build'
+            . ' --content-dir=' . escapeshellarg($contentDir)
+            . ' --output-dir=' . escapeshellarg($outputDir)
+            . ' --no-cache'
+            . ' 2>&1',
+            $output,
+            $exitCode,
+        );
+
+        $outputText = implode("\n", $output);
+
+        assertSame(ExitCode::DATAERR, $exitCode, $outputText);
+        assertStringContainsString('Refusing to clear', $outputText);
+        assertFileExists($outputDir . '/do-not-delete.html');
     }
 
     public function testBuildOutputContainsRenderedHtml(): void