fix(config): improve startup validation and config error reporting

src/config/config.test.ts

@@ -368,6 +368,29 @@ test('falls back for invalid logging.level and reports warning', () => {
   assert.ok(warnings.some((warning) => warning.path === 'logging.level'));
 });
 
+test('warns and ignores unknown top-level config keys', () => {
+  const dir = makeTempDir();
+  fs.writeFileSync(
+    path.join(dir, 'config.jsonc'),
+    `{
+      "websocket": {
+        "port": 7788
+      },
+      "unknownFeatureFlag": {
+        "enabled": true
+      }
+    }`,
+    'utf-8',
+  );
+
+  const service = new ConfigService(dir);
+  const config = service.getConfig();
+  const warnings = service.getWarnings();
+
+  assert.equal(config.websocket.port, 7788);
+  assert.ok(warnings.some((warning) => warning.path === 'unknownFeatureFlag'));
+});
+
 test('parses invisible overlay config and new global shortcuts', () => {
   const dir = makeTempDir();
   fs.writeFileSync(
@@ -634,6 +657,147 @@ test('supports legacy ankiConnect.behavior N+1 settings as fallback', () => {
   );
 });
 
+test('warns when ankiConnect.openRouter is used and migrates to ai', () => {
+  const dir = makeTempDir();
+  fs.writeFileSync(
+    path.join(dir, 'config.jsonc'),
+    `{
+      "ankiConnect": {
+        "openRouter": {
+          "model": "openrouter/test-model"
+        }
+      }
+    }`,
+    'utf-8',
+  );
+
+  const service = new ConfigService(dir);
+  const config = service.getConfig();
+  const warnings = service.getWarnings();
+
+  assert.equal((config.ankiConnect.ai as Record<string, unknown>).model, 'openrouter/test-model');
+  assert.ok(
+    warnings.some(
+      (warning) =>
+        warning.path === 'ankiConnect.openRouter' && warning.message.includes('ankiConnect.ai'),
+    ),
+  );
+});
+
+test('falls back and warns when legacy ankiConnect migration values are invalid', () => {
+  const dir = makeTempDir();
+  fs.writeFileSync(
+    path.join(dir, 'config.jsonc'),
+    `{
+      "ankiConnect": {
+        "audioField": 123,
+        "generateAudio": "yes",
+        "imageType": "gif",
+        "imageQuality": -1,
+        "mediaInsertMode": "middle",
+        "notificationType": "toast"
+      }
+    }`,
+    'utf-8',
+  );
+
+  const service = new ConfigService(dir);
+  const config = service.getConfig();
+  const warnings = service.getWarnings();
+
+  assert.equal(config.ankiConnect.fields.audio, DEFAULT_CONFIG.ankiConnect.fields.audio);
+  assert.equal(
+    config.ankiConnect.media.generateAudio,
+    DEFAULT_CONFIG.ankiConnect.media.generateAudio,
+  );
+  assert.equal(config.ankiConnect.media.imageType, DEFAULT_CONFIG.ankiConnect.media.imageType);
+  assert.equal(
+    config.ankiConnect.media.imageQuality,
+    DEFAULT_CONFIG.ankiConnect.media.imageQuality,
+  );
+  assert.equal(
+    config.ankiConnect.behavior.mediaInsertMode,
+    DEFAULT_CONFIG.ankiConnect.behavior.mediaInsertMode,
+  );
+  assert.equal(
+    config.ankiConnect.behavior.notificationType,
+    DEFAULT_CONFIG.ankiConnect.behavior.notificationType,
+  );
+
+  assert.ok(warnings.some((warning) => warning.path === 'ankiConnect.audioField'));
+  assert.ok(warnings.some((warning) => warning.path === 'ankiConnect.generateAudio'));
+  assert.ok(warnings.some((warning) => warning.path === 'ankiConnect.imageType'));
+  assert.ok(warnings.some((warning) => warning.path === 'ankiConnect.imageQuality'));
+  assert.ok(warnings.some((warning) => warning.path === 'ankiConnect.mediaInsertMode'));
+  assert.ok(warnings.some((warning) => warning.path === 'ankiConnect.notificationType'));
+});
+
+test('maps valid legacy ankiConnect values to equivalent modern config', () => {
+  const dir = makeTempDir();
+  fs.writeFileSync(
+    path.join(dir, 'config.jsonc'),
+    `{
+      "ankiConnect": {
+        "audioField": "AudioLegacy",
+        "imageField": "ImageLegacy",
+        "generateAudio": false,
+        "imageType": "avif",
+        "imageFormat": "webp",
+        "imageQuality": 88,
+        "mediaInsertMode": "prepend",
+        "notificationType": "both",
+        "autoUpdateNewCards": false
+      }
+    }`,
+    'utf-8',
+  );
+
+  const service = new ConfigService(dir);
+  const config = service.getConfig();
+
+  assert.equal(config.ankiConnect.fields.audio, 'AudioLegacy');
+  assert.equal(config.ankiConnect.fields.image, 'ImageLegacy');
+  assert.equal(config.ankiConnect.media.generateAudio, false);
+  assert.equal(config.ankiConnect.media.imageType, 'avif');
+  assert.equal(config.ankiConnect.media.imageFormat, 'webp');
+  assert.equal(config.ankiConnect.media.imageQuality, 88);
+  assert.equal(config.ankiConnect.behavior.mediaInsertMode, 'prepend');
+  assert.equal(config.ankiConnect.behavior.notificationType, 'both');
+  assert.equal(config.ankiConnect.behavior.autoUpdateNewCards, false);
+});
+
+test('ignores deprecated isLapis sentence-card field overrides', () => {
+  const dir = makeTempDir();
+  fs.writeFileSync(
+    path.join(dir, 'config.jsonc'),
+    `{
+      "ankiConnect": {
+        "isLapis": {
+          "enabled": true,
+          "sentenceCardModel": "Japanese sentences",
+          "sentenceCardSentenceField": "CustomSentence",
+          "sentenceCardAudioField": "CustomAudio"
+        }
+      }
+    }`,
+    'utf-8',
+  );
+
+  const service = new ConfigService(dir);
+  const config = service.getConfig();
+  const warnings = service.getWarnings();
+
+  const lapisConfig = config.ankiConnect.isLapis as Record<string, unknown>;
+  assert.equal(lapisConfig.sentenceCardSentenceField, undefined);
+  assert.equal(lapisConfig.sentenceCardAudioField, undefined);
+  assert.ok(
+    warnings.some((warning) => warning.path === 'ankiConnect.isLapis.sentenceCardSentenceField'),
+  );
+  assert.ok(
+    warnings.some((warning) => warning.path === 'ankiConnect.isLapis.sentenceCardAudioField'),
+  );
+});
+
 test('accepts valid ankiConnect n+1 deck list', () => {
   const dir = makeTempDir();
   fs.writeFileSync(

src/config/service.ts

@@ -212,6 +212,12 @@ export class ConfigService {
     };
 
     const src = isObject(raw) ? raw : {};
+    const knownTopLevelKeys = new Set(Object.keys(resolved));
+    for (const key of Object.keys(src)) {
+      if (!knownTopLevelKeys.has(key)) {
+        warn(key, src[key], undefined, 'Unknown top-level config key; ignored.');
+      }
+    }
 
     if (isObject(src.texthooker)) {
       const openBrowser = asBoolean(src.texthooker.openBrowser);
@@ -849,14 +855,57 @@ export class ConfigService {
     if (isObject(src.ankiConnect)) {
       const ac = src.ankiConnect;
       const behavior = isObject(ac.behavior) ? (ac.behavior as Record<string, unknown>) : {};
+      const fields = isObject(ac.fields) ? (ac.fields as Record<string, unknown>) : {};
+      const media = isObject(ac.media) ? (ac.media as Record<string, unknown>) : {};
+      const metadata = isObject(ac.metadata) ? (ac.metadata as Record<string, unknown>) : {};
       const aiSource = isObject(ac.ai) ? ac.ai : isObject(ac.openRouter) ? ac.openRouter : {};
+      const legacyKeys = new Set([
+        'audioField',
+        'imageField',
+        'sentenceField',
+        'miscInfoField',
+        'miscInfoPattern',
+        'generateAudio',
+        'generateImage',
+        'imageType',
+        'imageFormat',
+        'imageQuality',
+        'imageMaxWidth',
+        'imageMaxHeight',
+        'animatedFps',
+        'animatedMaxWidth',
+        'animatedMaxHeight',
+        'animatedCrf',
+        'audioPadding',
+        'fallbackDuration',
+        'maxMediaDuration',
+        'overwriteAudio',
+        'overwriteImage',
+        'mediaInsertMode',
+        'highlightWord',
+        'notificationType',
+        'autoUpdateNewCards',
+      ]);
+
+      if (ac.openRouter !== undefined) {
+        warn(
+          'ankiConnect.openRouter',
+          ac.openRouter,
+          resolved.ankiConnect.ai,
+          'Deprecated key; use ankiConnect.ai instead.',
+        );
+      }
+
       const { nPlusOne: _nPlusOneConfigFromAnkiConnect, ...ankiConnectWithoutNPlusOne } =
         ac as Record<string, unknown>;
+      const ankiConnectWithoutLegacy = Object.fromEntries(
+        Object.entries(ankiConnectWithoutNPlusOne).filter(([key]) => !legacyKeys.has(key)),
+      );
 
       resolved.ankiConnect = {
         ...resolved.ankiConnect,
-        ...(isObject(ankiConnectWithoutNPlusOne)
-          ? (ankiConnectWithoutNPlusOne as Partial<ResolvedConfig['ankiConnect']>)
+        ...(isObject(ankiConnectWithoutLegacy)
+          ? (ankiConnectWithoutLegacy as Partial<ResolvedConfig['ankiConnect']>)
           : {}),
         fields: {
           ...resolved.ankiConnect.fields,
@@ -884,7 +933,6 @@ export class ConfigService {
         },
         isLapis: {
           ...resolved.ankiConnect.isLapis,
-          ...(isObject(ac.isLapis) ? (ac.isLapis as ResolvedConfig['ankiConnect']['isLapis']) : {}),
         },
         isKiku: {
           ...resolved.ankiConnect.isKiku,
@@ -892,6 +940,52 @@ export class ConfigService {
         },
       };
 
+      if (isObject(ac.isLapis)) {
+        const lapisEnabled = asBoolean(ac.isLapis.enabled);
+        if (lapisEnabled !== undefined) {
+          resolved.ankiConnect.isLapis.enabled = lapisEnabled;
+        } else if (ac.isLapis.enabled !== undefined) {
+          warn(
+            'ankiConnect.isLapis.enabled',
+            ac.isLapis.enabled,
+            resolved.ankiConnect.isLapis.enabled,
+            'Expected boolean.',
+          );
+        }
+
+        const sentenceCardModel = asString(ac.isLapis.sentenceCardModel);
+        if (sentenceCardModel !== undefined) {
+          resolved.ankiConnect.isLapis.sentenceCardModel = sentenceCardModel;
+        } else if (ac.isLapis.sentenceCardModel !== undefined) {
+          warn(
+            'ankiConnect.isLapis.sentenceCardModel',
+            ac.isLapis.sentenceCardModel,
+            resolved.ankiConnect.isLapis.sentenceCardModel,
+            'Expected string.',
+          );
+        }
+
+        if (ac.isLapis.sentenceCardSentenceField !== undefined) {
+          warn(
+            'ankiConnect.isLapis.sentenceCardSentenceField',
+            ac.isLapis.sentenceCardSentenceField,
+            'Sentence',
+            'Deprecated key; sentence-card sentence field is fixed to Sentence.',
+          );
+        }
+
+        if (ac.isLapis.sentenceCardAudioField !== undefined) {
+          warn(
+            'ankiConnect.isLapis.sentenceCardAudioField',
+            ac.isLapis.sentenceCardAudioField,
+            'SentenceAudio',
+            'Deprecated key; sentence-card audio field is fixed to SentenceAudio.',
+          );
+        }
+      } else if (ac.isLapis !== undefined) {
+        warn('ankiConnect.isLapis', ac.isLapis, resolved.ankiConnect.isLapis, 'Expected object.');
+      }
+
       if (Array.isArray(ac.tags)) {
         const normalizedTags = ac.tags
           .filter((entry): entry is string => typeof entry === 'string')
@@ -919,89 +1013,344 @@ export class ConfigService {
       }
 
       const legacy = ac as Record<string, unknown>;
-      const mapLegacy = (key: string, apply: (value: unknown) => void): void => {
-        if (legacy[key] !== undefined) apply(legacy[key]);
+      const hasOwn = (obj: Record<string, unknown>, key: string): boolean =>
+        Object.prototype.hasOwnProperty.call(obj, key);
+      const asIntegerInRange = (value: unknown, min: number, max: number): number | undefined => {
+        const parsed = asNumber(value);
+        if (parsed === undefined || !Number.isInteger(parsed) || parsed < min || parsed > max) {
+          return undefined;
+        }
+        return parsed;
+      };
+      const asPositiveInteger = (value: unknown): number | undefined => {
+        const parsed = asNumber(value);
+        if (parsed === undefined || !Number.isInteger(parsed) || parsed <= 0) {
+          return undefined;
+        }
+        return parsed;
+      };
+      const asPositiveNumber = (value: unknown): number | undefined => {
+        const parsed = asNumber(value);
+        if (parsed === undefined || parsed <= 0) {
+          return undefined;
+        }
+        return parsed;
+      };
+      const asNonNegativeNumber = (value: unknown): number | undefined => {
+        const parsed = asNumber(value);
+        if (parsed === undefined || parsed < 0) {
+          return undefined;
+        }
+        return parsed;
+      };
+      const asImageType = (value: unknown): 'static' | 'avif' | undefined => {
+        return value === 'static' || value === 'avif' ? value : undefined;
+      };
+      const asImageFormat = (value: unknown): 'jpg' | 'png' | 'webp' | undefined => {
+        return value === 'jpg' || value === 'png' || value === 'webp' ? value : undefined;
+      };
+      const asMediaInsertMode = (value: unknown): 'append' | 'prepend' | undefined => {
+        return value === 'append' || value === 'prepend' ? value : undefined;
+      };
+      const asNotificationType = (
+        value: unknown,
+      ): 'osd' | 'system' | 'both' | 'none' | undefined => {
+        return value === 'osd' || value === 'system' || value === 'both' || value === 'none'
+          ? value
+          : undefined;
+      };
+      const mapLegacy = <T>(
+        key: string,
+        parse: (value: unknown) => T | undefined,
+        apply: (value: T) => void,
+        fallback: unknown,
+        message: string,
+      ): void => {
+        const value = legacy[key];
+        if (value === undefined) return;
+        const parsed = parse(value);
+        if (parsed === undefined) {
+          warn(`ankiConnect.${key}`, value, fallback, message);
+          return;
+        }
+        apply(parsed);
       };
 
-      mapLegacy('audioField', (value) => {
-        resolved.ankiConnect.fields.audio = value as string;
-      });
-      mapLegacy('imageField', (value) => {
-        resolved.ankiConnect.fields.image = value as string;
-      });
-      mapLegacy('sentenceField', (value) => {
-        resolved.ankiConnect.fields.sentence = value as string;
-      });
-      mapLegacy('miscInfoField', (value) => {
-        resolved.ankiConnect.fields.miscInfo = value as string;
-      });
-      mapLegacy('miscInfoPattern', (value) => {
-        resolved.ankiConnect.metadata.pattern = value as string;
-      });
-      mapLegacy('generateAudio', (value) => {
-        resolved.ankiConnect.media.generateAudio = value as boolean;
-      });
-      mapLegacy('generateImage', (value) => {
-        resolved.ankiConnect.media.generateImage = value as boolean;
-      });
-      mapLegacy('imageType', (value) => {
-        resolved.ankiConnect.media.imageType = value as 'static' | 'avif';
-      });
-      mapLegacy('imageFormat', (value) => {
-        resolved.ankiConnect.media.imageFormat = value as 'jpg' | 'png' | 'webp';
-      });
-      mapLegacy('imageQuality', (value) => {
-        resolved.ankiConnect.media.imageQuality = value as number;
-      });
-      mapLegacy('imageMaxWidth', (value) => {
-        resolved.ankiConnect.media.imageMaxWidth = value as number;
-      });
-      mapLegacy('imageMaxHeight', (value) => {
-        resolved.ankiConnect.media.imageMaxHeight = value as number;
-      });
-      mapLegacy('animatedFps', (value) => {
-        resolved.ankiConnect.media.animatedFps = value as number;
-      });
-      mapLegacy('animatedMaxWidth', (value) => {
-        resolved.ankiConnect.media.animatedMaxWidth = value as number;
-      });
-      mapLegacy('animatedMaxHeight', (value) => {
-        resolved.ankiConnect.media.animatedMaxHeight = value as number;
-      });
-      mapLegacy('animatedCrf', (value) => {
-        resolved.ankiConnect.media.animatedCrf = value as number;
-      });
-      mapLegacy('audioPadding', (value) => {
-        resolved.ankiConnect.media.audioPadding = value as number;
-      });
-      mapLegacy('fallbackDuration', (value) => {
-        resolved.ankiConnect.media.fallbackDuration = value as number;
-      });
-      mapLegacy('maxMediaDuration', (value) => {
-        resolved.ankiConnect.media.maxMediaDuration = value as number;
-      });
-      mapLegacy('overwriteAudio', (value) => {
-        resolved.ankiConnect.behavior.overwriteAudio = value as boolean;
-      });
-      mapLegacy('overwriteImage', (value) => {
-        resolved.ankiConnect.behavior.overwriteImage = value as boolean;
-      });
-      mapLegacy('mediaInsertMode', (value) => {
-        resolved.ankiConnect.behavior.mediaInsertMode = value as 'append' | 'prepend';
-      });
-      mapLegacy('highlightWord', (value) => {
-        resolved.ankiConnect.behavior.highlightWord = value as boolean;
-      });
-      mapLegacy('notificationType', (value) => {
-        resolved.ankiConnect.behavior.notificationType = value as
-          | 'osd'
-          | 'system'
-          | 'both'
-          | 'none';
-      });
-      mapLegacy('autoUpdateNewCards', (value) => {
-        resolved.ankiConnect.behavior.autoUpdateNewCards = value as boolean;
-      });
+      if (!hasOwn(fields, 'audio')) {
+        mapLegacy(
+          'audioField',
+          asString,
+          (value) => {
+            resolved.ankiConnect.fields.audio = value;
+          },
+          resolved.ankiConnect.fields.audio,
+          'Expected string.',
+        );
+      }
+      if (!hasOwn(fields, 'image')) {
+        mapLegacy(
+          'imageField',
+          asString,
+          (value) => {
+            resolved.ankiConnect.fields.image = value;
+          },
+          resolved.ankiConnect.fields.image,
+          'Expected string.',
+        );
+      }
+      if (!hasOwn(fields, 'sentence')) {
+        mapLegacy(
+          'sentenceField',
+          asString,
+          (value) => {
+            resolved.ankiConnect.fields.sentence = value;
+          },
+          resolved.ankiConnect.fields.sentence,
+          'Expected string.',
+        );
+      }
+      if (!hasOwn(fields, 'miscInfo')) {
+        mapLegacy(
+          'miscInfoField',
+          asString,
+          (value) => {
+            resolved.ankiConnect.fields.miscInfo = value;
+          },
+          resolved.ankiConnect.fields.miscInfo,
+          'Expected string.',
+        );
+      }
+      if (!hasOwn(metadata, 'pattern')) {
+        mapLegacy(
+          'miscInfoPattern',
+          asString,
+          (value) => {
+            resolved.ankiConnect.metadata.pattern = value;
+          },
+          resolved.ankiConnect.metadata.pattern,
+          'Expected string.',
+        );
+      }
+      if (!hasOwn(media, 'generateAudio')) {
+        mapLegacy(
+          'generateAudio',
+          asBoolean,
+          (value) => {
+            resolved.ankiConnect.media.generateAudio = value;
+          },
+          resolved.ankiConnect.media.generateAudio,
+          'Expected boolean.',
+        );
+      }
+      if (!hasOwn(media, 'generateImage')) {
+        mapLegacy(
+          'generateImage',
+          asBoolean,
+          (value) => {
+            resolved.ankiConnect.media.generateImage = value;
+          },
+          resolved.ankiConnect.media.generateImage,
+          'Expected boolean.',
+        );
+      }
+      if (!hasOwn(media, 'imageType')) {
+        mapLegacy(
+          'imageType',
+          asImageType,
+          (value) => {
+            resolved.ankiConnect.media.imageType = value;
+          },
+          resolved.ankiConnect.media.imageType,
+          "Expected 'static' or 'avif'.",
+        );
+      }
+      if (!hasOwn(media, 'imageFormat')) {
+        mapLegacy(
+          'imageFormat',
+          asImageFormat,
+          (value) => {
+            resolved.ankiConnect.media.imageFormat = value;
+          },
+          resolved.ankiConnect.media.imageFormat,
+          "Expected 'jpg', 'png', or 'webp'.",
+        );
+      }
+      if (!hasOwn(media, 'imageQuality')) {
+        mapLegacy(
+          'imageQuality',
+          (value) => asIntegerInRange(value, 1, 100),
+          (value) => {
+            resolved.ankiConnect.media.imageQuality = value;
+          },
+          resolved.ankiConnect.media.imageQuality,
+          'Expected integer between 1 and 100.',
+        );
+      }
+      if (!hasOwn(media, 'imageMaxWidth')) {
+        mapLegacy(
+          'imageMaxWidth',
+          asPositiveInteger,
+          (value) => {
+            resolved.ankiConnect.media.imageMaxWidth = value;
+          },
+          resolved.ankiConnect.media.imageMaxWidth,
+          'Expected positive integer.',
+        );
+      }
+      if (!hasOwn(media, 'imageMaxHeight')) {
+        mapLegacy(
+          'imageMaxHeight',
+          asPositiveInteger,
+          (value) => {
+            resolved.ankiConnect.media.imageMaxHeight = value;
+          },
+          resolved.ankiConnect.media.imageMaxHeight,
+          'Expected positive integer.',
+        );
+      }
+      if (!hasOwn(media, 'animatedFps')) {
+        mapLegacy(
+          'animatedFps',
+          (value) => asIntegerInRange(value, 1, 60),
+          (value) => {
+            resolved.ankiConnect.media.animatedFps = value;
+          },
+          resolved.ankiConnect.media.animatedFps,
+          'Expected integer between 1 and 60.',
+        );
+      }
+      if (!hasOwn(media, 'animatedMaxWidth')) {
+        mapLegacy(
+          'animatedMaxWidth',
+          asPositiveInteger,
+          (value) => {
+            resolved.ankiConnect.media.animatedMaxWidth = value;
+          },
+          resolved.ankiConnect.media.animatedMaxWidth,
+          'Expected positive integer.',
+        );
+      }
+      if (!hasOwn(media, 'animatedMaxHeight')) {
+        mapLegacy(
+          'animatedMaxHeight',
+          asPositiveInteger,
+          (value) => {
+            resolved.ankiConnect.media.animatedMaxHeight = value;
+          },
+          resolved.ankiConnect.media.animatedMaxHeight,
+          'Expected positive integer.',
+        );
+      }
+      if (!hasOwn(media, 'animatedCrf')) {
+        mapLegacy(
+          'animatedCrf',
+          (value) => asIntegerInRange(value, 0, 63),
+          (value) => {
+            resolved.ankiConnect.media.animatedCrf = value;
+          },
+          resolved.ankiConnect.media.animatedCrf,
+          'Expected integer between 0 and 63.',
+        );
+      }
+      if (!hasOwn(media, 'audioPadding')) {
+        mapLegacy(
+          'audioPadding',
+          asNonNegativeNumber,
+          (value) => {
+            resolved.ankiConnect.media.audioPadding = value;
+          },
+          resolved.ankiConnect.media.audioPadding,
+          'Expected non-negative number.',
+        );
+      }
+      if (!hasOwn(media, 'fallbackDuration')) {
+        mapLegacy(
+          'fallbackDuration',
+          asPositiveNumber,
+          (value) => {
+            resolved.ankiConnect.media.fallbackDuration = value;
+          },
+          resolved.ankiConnect.media.fallbackDuration,
+          'Expected positive number.',
+        );
+      }
+      if (!hasOwn(media, 'maxMediaDuration')) {
+        mapLegacy(
+          'maxMediaDuration',
+          asNonNegativeNumber,
+          (value) => {
+            resolved.ankiConnect.media.maxMediaDuration = value;
+          },
+          resolved.ankiConnect.media.maxMediaDuration,
+          'Expected non-negative number.',
+        );
+      }
+      if (!hasOwn(behavior, 'overwriteAudio')) {
+        mapLegacy(
+          'overwriteAudio',
+          asBoolean,
+          (value) => {
+            resolved.ankiConnect.behavior.overwriteAudio = value;
+          },
+          resolved.ankiConnect.behavior.overwriteAudio,
+          'Expected boolean.',
+        );
+      }
+      if (!hasOwn(behavior, 'overwriteImage')) {
+        mapLegacy(
+          'overwriteImage',
+          asBoolean,
+          (value) => {
+            resolved.ankiConnect.behavior.overwriteImage = value;
+          },
+          resolved.ankiConnect.behavior.overwriteImage,
+          'Expected boolean.',
+        );
+      }
+      if (!hasOwn(behavior, 'mediaInsertMode')) {
+        mapLegacy(
+          'mediaInsertMode',
+          asMediaInsertMode,
+          (value) => {
+            resolved.ankiConnect.behavior.mediaInsertMode = value;
+          },
+          resolved.ankiConnect.behavior.mediaInsertMode,
+          "Expected 'append' or 'prepend'.",
+        );
+      }
+      if (!hasOwn(behavior, 'highlightWord')) {
+        mapLegacy(
+          'highlightWord',
+          asBoolean,
+          (value) => {
+            resolved.ankiConnect.behavior.highlightWord = value;
+          },
+          resolved.ankiConnect.behavior.highlightWord,
+          'Expected boolean.',
+        );
+      }
+      if (!hasOwn(behavior, 'notificationType')) {
+        mapLegacy(
+          'notificationType',
+          asNotificationType,
+          (value) => {
+            resolved.ankiConnect.behavior.notificationType = value;
+          },
+          resolved.ankiConnect.behavior.notificationType,
+          "Expected 'osd', 'system', 'both', or 'none'.",
+        );
+      }
+      if (!hasOwn(behavior, 'autoUpdateNewCards')) {
+        mapLegacy(
+          'autoUpdateNewCards',
+          asBoolean,
+          (value) => {
+            resolved.ankiConnect.behavior.autoUpdateNewCards = value;
+          },
+          resolved.ankiConnect.behavior.autoUpdateNewCards,
+          'Expected boolean.',
+        );
+      }
 
       const nPlusOneConfig = isObject(ac.nPlusOne) ? (ac.nPlusOne as Record<string, unknown>) : {};
 

src/core/services/app-ready.test.ts

@@ -149,3 +149,92 @@ test('runAppReadyRuntime does not await background warmups', async () => {
   assert.ok(releaseWarmup);
   releaseWarmup();
 });
+
+test('runAppReadyRuntime exits before service init when critical anki mappings are invalid', async () => {
+  const capturedErrors: string[][] = [];
+  const { deps, calls } = makeDeps({
+    getResolvedConfig: () => ({
+      websocket: { enabled: 'auto' },
+      secondarySub: {},
+      ankiConnect: {
+        enabled: true,
+        fields: {
+          audio: 'ExpressionAudio',
+          image: 'Picture',
+          sentence: '   ',
+          miscInfo: 'MiscInfo',
+          translation: '',
+        },
+      },
+    }),
+    onCriticalConfigErrors: (errors) => {
+      capturedErrors.push(errors);
+    },
+  });
+
+  await runAppReadyRuntime(deps);
+
+  assert.equal(capturedErrors.length, 1);
+  assert.deepEqual(capturedErrors[0], [
+    'ankiConnect.fields.sentence must be a non-empty string when ankiConnect is enabled.',
+    'ankiConnect.fields.translation must be a non-empty string when ankiConnect is enabled.',
+  ]);
+  assert.ok(calls.includes('reloadConfig'));
+  assert.equal(calls.includes('createMpvClient'), false);
+  assert.equal(calls.includes('initRuntimeOptionsManager'), false);
+  assert.equal(calls.includes('startBackgroundWarmups'), false);
+});
+
+test('runAppReadyRuntime aggregates multiple critical anki mapping errors', async () => {
+  const capturedErrors: string[][] = [];
+  const { deps, calls } = makeDeps({
+    getResolvedConfig: () => ({
+      websocket: { enabled: 'auto' },
+      secondarySub: {},
+      ankiConnect: {
+        enabled: true,
+        fields: {
+          audio: ' ',
+          image: '',
+          sentence: '\t',
+          miscInfo: '   ',
+          translation: '',
+        },
+      },
+    }),
+    onCriticalConfigErrors: (errors) => {
+      capturedErrors.push(errors);
+    },
+  });
+
+  await runAppReadyRuntime(deps);
+
+  assert.equal(capturedErrors.length, 1);
+  assert.equal(capturedErrors[0].length, 5);
+  assert.ok(
+    capturedErrors[0].includes(
+      'ankiConnect.fields.audio must be a non-empty string when ankiConnect is enabled.',
+    ),
+  );
+  assert.ok(
+    capturedErrors[0].includes(
+      'ankiConnect.fields.image must be a non-empty string when ankiConnect is enabled.',
+    ),
+  );
+  assert.ok(
+    capturedErrors[0].includes(
+      'ankiConnect.fields.sentence must be a non-empty string when ankiConnect is enabled.',
+    ),
+  );
+  assert.ok(
+    capturedErrors[0].includes(
+      'ankiConnect.fields.miscInfo must be a non-empty string when ankiConnect is enabled.',
+    ),
+  );
+  assert.ok(
+    capturedErrors[0].includes(
+      'ankiConnect.fields.translation must be a non-empty string when ankiConnect is enabled.',
+    ),
+  );
+  assert.equal(calls.includes('loadSubtitlePosition'), false);
+});

src/core/services/startup.ts

@@ -76,6 +76,16 @@ interface AppReadyConfigLike {
   secondarySub?: {
     defaultMode?: SecondarySubMode;
   };
+  ankiConnect?: {
+    enabled?: boolean;
+    fields?: {
+      audio?: string;
+      image?: string;
+      sentence?: string;
+      miscInfo?: string;
+      translation?: string;
+    };
+  };
   websocket?: {
     enabled?: boolean | 'auto';
     port?: number;
@@ -113,9 +123,38 @@ export interface AppReadyRuntimeDeps {
   initializeOverlayRuntime: () => void;
   handleInitialArgs: () => void;
   logDebug?: (message: string) => void;
+  onCriticalConfigErrors?: (errors: string[]) => void;
   now?: () => number;
 }
 
+const REQUIRED_ANKI_FIELD_MAPPING_KEYS = [
+  'audio',
+  'image',
+  'sentence',
+  'miscInfo',
+  'translation',
+] as const;
+
+function getStartupCriticalConfigErrors(config: AppReadyConfigLike): string[] {
+  if (!config.ankiConnect?.enabled) {
+    return [];
+  }
+
+  const errors: string[] = [];
+  const fields = config.ankiConnect.fields ?? {};
+
+  for (const key of REQUIRED_ANKI_FIELD_MAPPING_KEYS) {
+    const value = fields[key];
+    if (typeof value !== 'string' || value.trim().length === 0) {
+      errors.push(
+        `ankiConnect.fields.${key} must be a non-empty string when ankiConnect is enabled.`,
+      );
+    }
+  }
+
+  return errors;
+}
+
 export function getInitialInvisibleOverlayVisibility(
   config: RuntimeConfigLike,
   platform: NodeJS.Platform,
@@ -151,16 +190,25 @@ export async function runAppReadyRuntime(deps: AppReadyRuntimeDeps): Promise<voi
   const startupStartedAtMs = now();
   deps.logDebug?.('App-ready critical path started.');
 
-  deps.loadSubtitlePosition();
-  deps.resolveKeybindings();
-  deps.createMpvClient();
-
   deps.reloadConfig();
   const config = deps.getResolvedConfig();
+  const criticalConfigErrors = getStartupCriticalConfigErrors(config);
+  if (criticalConfigErrors.length > 0) {
+    deps.onCriticalConfigErrors?.(criticalConfigErrors);
+    deps.logDebug?.(
+      `App-ready critical path aborted after config validation in ${now() - startupStartedAtMs}ms.`,
+    );
+    return;
+  }
+
   deps.setLogLevel(config.logging?.level ?? 'info', 'config');
   for (const warning of deps.getConfigWarnings()) {
     deps.logConfigWarning(warning);
   }
+
+  deps.loadSubtitlePosition();
+  deps.resolveKeybindings();
+  deps.createMpvClient();
   deps.initRuntimeOptionsManager();
   deps.setSecondarySubMode(config.secondarySub?.defaultMode ?? deps.defaultSecondarySubMode);
 

src/main.ts

@@ -26,6 +26,7 @@ import {
   Menu,
   Tray,
   nativeImage,
+  dialog,
 } from 'electron';
 
 protocol.registerSchemesAsPrivileged([
@@ -61,6 +62,7 @@ import type {
   MpvSubtitleRenderMetrics,
   ResolvedConfig,
   ConfigHotReloadPayload,
+  ConfigValidationWarning,
 } from './types';
 import { SubtitleTimingTracker } from './subtitle-timing-tracker';
 import { AnkiIntegration } from './anki-integration';
@@ -334,6 +336,40 @@ const appLogger = {
   },
 };
 
+function formatConfigValue(value: unknown): string {
+  if (value === undefined) {
+    return 'undefined';
+  }
+
+  try {
+    return JSON.stringify(value);
+  } catch {
+    return String(value);
+  }
+}
+
+function buildConfigWarningSummary(
+  configPath: string,
+  warnings: ConfigValidationWarning[],
+): string {
+  const lines = [
+    `[config] Validation found ${warnings.length} issue(s). File: ${configPath}`,
+    ...warnings.map(
+      (warning, index) =>
+        `[config] ${index + 1}. ${warning.path}: ${warning.message} actual=${formatConfigValue(warning.value)} fallback=${formatConfigValue(warning.fallback)}`,
+    ),
+  ];
+  return lines.join('\n');
+}
+
+function failStartupFromConfig(title: string, details: string): never {
+  logger.error(details);
+  dialog.showErrorBox(title, details);
+  process.exitCode = 1;
+  app.quit();
+  throw new Error(details);
+}
+
 function getDefaultSocketPath(): string {
   if (process.platform === 'win32') {
     return '\\\\.\\pipe\\subminer-socket';
@@ -2187,8 +2223,22 @@ const startupState = runStartupBootstrapRuntime(
           appState.mpvClient = createMpvClientRuntimeService();
         },
         reloadConfig: () => {
-          configService.reloadConfig();
-          appLogger.logInfo(`Using config file: ${configService.getConfigPath()}`);
+          const result = configService.reloadConfigStrict();
+          if (!result.ok) {
+            failStartupFromConfig(
+              'SubMiner config parse error',
+              `Failed to parse config file at:\n${result.path}\n\nError: ${result.error}\n\nFix the config file and restart SubMiner.`,
+            );
+          }
+
+          appLogger.logInfo(`Using config file: ${result.path}`);
+          if (result.warnings.length > 0) {
+            appLogger.logWarning(buildConfigWarningSummary(result.path, result.warnings));
+            showDesktopNotification('SubMiner', {
+              body: `${result.warnings.length} config validation issue(s) detected. Defaults were applied where possible. File: ${result.path}`,
+            });
+          }
+
           configHotReloadRuntime.start();
           void refreshAnilistClientSecretState({ force: true });
         },
@@ -2285,6 +2335,17 @@ const startupState = runStartupBootstrapRuntime(
           appState.backgroundMode ? false : shouldAutoInitializeOverlayRuntimeFromConfig(),
         initializeOverlayRuntime: () => initializeOverlayRuntime(),
         handleInitialArgs: () => handleInitialArgs(),
+        onCriticalConfigErrors: (errors: string[]) => {
+          const configPath = configService.getConfigPath();
+          const details = [
+            `Critical config validation failed. File: ${configPath}`,
+            '',
+            ...errors.map((error, index) => `${index + 1}. ${error}`),
+            '',
+            'Fix the config file and restart SubMiner.',
+          ].join('\n');
+          failStartupFromConfig('SubMiner config validation error', details);
+        },
         logDebug: (message: string) => {
           logger.debug(message);
         },

src/main/app-lifecycle.ts

@@ -45,6 +45,7 @@ export interface AppReadyRuntimeDepsFactoryInput {
   shouldAutoInitializeOverlayRuntimeFromConfig: AppReadyRuntimeDeps['shouldAutoInitializeOverlayRuntimeFromConfig'];
   initializeOverlayRuntime: AppReadyRuntimeDeps['initializeOverlayRuntime'];
   handleInitialArgs: AppReadyRuntimeDeps['handleInitialArgs'];
+  onCriticalConfigErrors?: AppReadyRuntimeDeps['onCriticalConfigErrors'];
   logDebug?: AppReadyRuntimeDeps['logDebug'];
   now?: AppReadyRuntimeDeps['now'];
 }
@@ -99,6 +100,7 @@ export function createAppReadyRuntimeDeps(
       params.shouldAutoInitializeOverlayRuntimeFromConfig,
     initializeOverlayRuntime: params.initializeOverlayRuntime,
     handleInitialArgs: params.handleInitialArgs,
+    onCriticalConfigErrors: params.onCriticalConfigErrors,
     logDebug: params.logDebug,
     now: params.now,
   };