M3-AP-007: Startvalidierung für Quellordner testbar gemacht

pdf-umbenenner-application/src/test/java/de/gecheckt/pdf/umbenenner/application/config/StartConfigurationValidatorTest.java

@@ -683,4 +683,153 @@ class StartConfigurationValidatorTest {
         assertTrue(message.contains("max.pages: must be > 0"));
         assertTrue(message.contains("max.text.characters: must be > 0"));
     }
+
+    /**
+     * M3/AP-007: Focused tests for source folder validation using mocked filesystem checks.
+     * <p>
+     * These tests verify the four critical paths for source folder validation without
+     * relying on platform-dependent filesystem permissions or the actual FS state.
+     */
+
+    @Test
+    void validate_failsWhenSourceFolderDoesNotExist_mocked() throws Exception {
+        Path targetFolder = Files.createDirectory(tempDir.resolve("target"));
+        Path sqliteFile = Files.createFile(tempDir.resolve("db.sqlite"));
+        Path promptTemplateFile = Files.createFile(tempDir.resolve("prompt.txt"));
+
+        StartConfiguration config = new StartConfiguration(
+                tempDir.resolve("nonexistent"),
+                targetFolder,
+                sqliteFile,
+                URI.create("https://api.example.com"),
+                "gpt-4",
+                30,
+                3,
+                100,
+                50000,
+                promptTemplateFile,
+                null,
+                null,
+                "INFO",
+                "test-api-key"
+        );
+
+        // Mock: always return "does not exist" error for any path
+        StartConfigurationValidator.SourceFolderChecker mockChecker = path ->
+            "- source.folder: path does not exist: " + path;
+
+        StartConfigurationValidator validatorWithMock = new StartConfigurationValidator(mockChecker);
+
+        InvalidStartConfigurationException exception = assertThrows(
+                InvalidStartConfigurationException.class,
+                () -> validatorWithMock.validate(config)
+        );
+        assertTrue(exception.getMessage().contains("source.folder: path does not exist"));
+    }
+
+    @Test
+    void validate_failsWhenSourceFolderIsNotADirectory_mocked() throws Exception {
+        Path targetFolder = Files.createDirectory(tempDir.resolve("target"));
+        Path sqliteFile = Files.createFile(tempDir.resolve("db.sqlite"));
+        Path promptTemplateFile = Files.createFile(tempDir.resolve("prompt.txt"));
+
+        StartConfiguration config = new StartConfiguration(
+                tempDir.resolve("somepath"),
+                targetFolder,
+                sqliteFile,
+                URI.create("https://api.example.com"),
+                "gpt-4",
+                30,
+                3,
+                100,
+                50000,
+                promptTemplateFile,
+                null,
+                null,
+                "INFO",
+                "test-api-key"
+        );
+
+        // Mock: simulate path exists but is not a directory
+        StartConfigurationValidator.SourceFolderChecker mockChecker = path ->
+            "- source.folder: path is not a directory: " + path;
+
+        StartConfigurationValidator validatorWithMock = new StartConfigurationValidator(mockChecker);
+
+        InvalidStartConfigurationException exception = assertThrows(
+                InvalidStartConfigurationException.class,
+                () -> validatorWithMock.validate(config)
+        );
+        assertTrue(exception.getMessage().contains("source.folder: path is not a directory"));
+    }
+
+    @Test
+    void validate_failsWhenSourceFolderIsNotReadable_mocked() throws Exception {
+        Path targetFolder = Files.createDirectory(tempDir.resolve("target"));
+        Path sqliteFile = Files.createFile(tempDir.resolve("db.sqlite"));
+        Path promptTemplateFile = Files.createFile(tempDir.resolve("prompt.txt"));
+
+        StartConfiguration config = new StartConfiguration(
+                tempDir.resolve("somepath"),
+                targetFolder,
+                sqliteFile,
+                URI.create("https://api.example.com"),
+                "gpt-4",
+                30,
+                3,
+                100,
+                50000,
+                promptTemplateFile,
+                null,
+                null,
+                "INFO",
+                "test-api-key"
+        );
+
+        // Mock: simulate path exists, is directory, but is not readable
+        // This is the critical M3/AP-007 case that is hard to test on actual FS
+        StartConfigurationValidator.SourceFolderChecker mockChecker = path ->
+            "- source.folder: directory is not readable: " + path;
+
+        StartConfigurationValidator validatorWithMock = new StartConfigurationValidator(mockChecker);
+
+        InvalidStartConfigurationException exception = assertThrows(
+                InvalidStartConfigurationException.class,
+                () -> validatorWithMock.validate(config)
+        );
+        assertTrue(exception.getMessage().contains("source.folder: directory is not readable"));
+    }
+
+    @Test
+    void validate_succeedsWhenSourceFolderIsValid_mocked() throws Exception {
+        Path sourceFolder = Files.createDirectory(tempDir.resolve("source"));
+        Path targetFolder = Files.createDirectory(tempDir.resolve("target"));
+        Path sqliteFile = Files.createFile(tempDir.resolve("db.sqlite"));
+        Path promptTemplateFile = Files.createFile(tempDir.resolve("prompt.txt"));
+
+        StartConfiguration config = new StartConfiguration(
+                sourceFolder,
+                targetFolder,
+                sqliteFile,
+                URI.create("https://api.example.com"),
+                "gpt-4",
+                30,
+                3,
+                100,
+                50000,
+                promptTemplateFile,
+                null,
+                null,
+                "INFO",
+                "test-api-key"
+        );
+
+        // Mock: all checks pass (return null)
+        StartConfigurationValidator.SourceFolderChecker mockChecker = path -> null;
+
+        StartConfigurationValidator validatorWithMock = new StartConfigurationValidator(mockChecker);
+
+        assertDoesNotThrow(() -> validatorWithMock.validate(config),
+                "Validation should succeed when source folder checker returns null");
+    }
 }