feat(i18n): add internationalization support FR/EN (#45)

DGouron · claude · DGouron · commit c41f4fe56364 · 2026-02-14T14:01:38.000+01:00
Add language configuration per project with system prompt injection
to force Claude reviews in the configured language. Dashboard includes
a language toggle matching the existing model selector pattern.

Co-Authored-By: Claude Opus 4.6 &lt;noreply@anthropic.com&gt;
diff --git a/src/config/projectConfig.ts b/src/config/projectConfig.ts
@@ -1,6 +1,7 @@
 import { readFileSync, existsSync } from 'node:fs';
 import { join } from 'node:path';
-import type { AgentDefinition } from '../entities/progress/agentDefinition.type.js';
+import type { AgentDefinition } from '@/entities/progress/agentDefinition.type.js';
+import type { Language } from '@/entities/language/language.schema.js';
 
 /**
  * Project-specific review configuration
@@ -12,6 +13,7 @@ export interface ProjectConfig {
   defaultModel: 'sonnet' | 'opus';
   reviewSkill: string;
   reviewFollowupSkill: string;
+  language: Language;
   agents?: AgentDefinition[];
   followupAgents?: AgentDefinition[];
 }
@@ -88,6 +90,7 @@ export function loadProjectConfig(localPath: string): ProjectConfig | undefined
     defaultModel: parsed.defaultModel === 'opus' ? 'opus' : 'sonnet',
     reviewSkill: String(parsed.reviewSkill),
     reviewFollowupSkill: String(parsed.reviewFollowupSkill),
+    language: parsed.language === 'fr' ? 'fr' : 'en',
     agents: parsed.agents as AgentDefinition[] | undefined,
     followupAgents: parsed.followupAgents as AgentDefinition[] | undefined,
   };
@@ -105,6 +108,18 @@ export function getProjectAgents(localPath: string): AgentDefinition[] | undefin
   }
 }
 
+/**
+ * Get language from project config, defaulting to 'en'
+ */
+export function getProjectLanguage(localPath: string): Language {
+  try {
+    const config = loadProjectConfig(localPath);
+    return config?.language ?? 'en';
+  } catch {
+    return 'en';
+  }
+}
+
 /**
  * Get followup agents from project config or undefined for defaults
  */
diff --git a/src/entities/language/language.schema.ts b/src/entities/language/language.schema.ts
@@ -0,0 +1,5 @@
+import { z } from 'zod';
+
+export const languageSchema = z.enum(['en', 'fr']);
+
+export type Language = z.infer<typeof languageSchema>;
diff --git a/src/frameworks/claude/claudeInvoker.ts b/src/frameworks/claude/claudeInvoker.ts
@@ -3,17 +3,18 @@ import { writeFileSync, mkdirSync, existsSync, unlinkSync, readFileSync } from '
 import { join, dirname } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import type { Logger } from 'pino';
-import type { ReviewJob } from '../queue/pQueueAdapter.js';
-import type { ReviewProgress, ProgressEvent } from '../../entities/progress/progress.type.js';
-import { ProgressParser } from './progressParser.js';
-import { logInfo, logWarn, logError } from '../logging/logBuffer.js';
-import { getModel } from '../settings/runtimeSettings.js';
-import { getProjectAgents, getFollowupAgents } from '../../config/projectConfig.js';
-import { addReviewStats } from '../../services/statsService.js';
-import { FileSystemReviewRequestTrackingGateway } from '../../interface-adapters/gateways/fileSystem/reviewRequestTracking.fileSystem.js';
-import { ProjectStatsCalculator } from '../../interface-adapters/presenters/projectStats.calculator.js';
-import { resolveClaudePath } from '../../shared/services/claudePathResolver.js';
-import { getJobContextFilePath } from '../../shared/services/mcpJobContext.js';
+import type { ReviewJob } from '@/frameworks/queue/pQueueAdapter.js';
+import type { ReviewProgress, ProgressEvent } from '@/entities/progress/progress.type.js';
+import { ProgressParser } from '@/frameworks/claude/progressParser.js';
+import { logInfo, logWarn, logError } from '@/frameworks/logging/logBuffer.js';
+import { getModel } from '@/frameworks/settings/runtimeSettings.js';
+import { getProjectAgents, getFollowupAgents } from '@/config/projectConfig.js';
+import { addReviewStats } from '@/services/statsService.js';
+import { FileSystemReviewRequestTrackingGateway } from '@/interface-adapters/gateways/fileSystem/reviewRequestTracking.fileSystem.js';
+import { ProjectStatsCalculator } from '@/interface-adapters/presenters/projectStats.calculator.js';
+import { resolveClaudePath } from '@/shared/services/claudePathResolver.js';
+import { getJobContextFilePath } from '@/shared/services/mcpJobContext.js';
+import { buildLanguageDirective } from '@/frameworks/claude/languageDirective.js';
 
 const currentDir = dirname(fileURLToPath(import.meta.url));
 
@@ -204,6 +205,8 @@ Use \`POST_INLINE_COMMENT\` to post comments directly on specific lines in the d
 - Producing a "plan" instead of executing → Review will be empty
 - Using text markers like [PROGRESS:xxx] → Dashboard won't update
 - Waiting for user approval → Review will hang forever
+
+${buildLanguageDirective(job.language ?? 'en')}
 `.trim();
 }
 
diff --git a/src/frameworks/claude/languageDirective.ts b/src/frameworks/claude/languageDirective.ts
@@ -0,0 +1,11 @@
+import type { Language } from '@/entities/language/language.schema.js';
+
+const LANGUAGE_LABELS: Record<Language, string> = {
+  en: 'English',
+  fr: 'French',
+};
+
+export function buildLanguageDirective(language: Language): string {
+  const label = LANGUAGE_LABELS[language];
+  return `## MANDATORY OUTPUT LANGUAGE\n\nCRITICAL: WRITE YOUR ENTIRE REVIEW IN ${label.toUpperCase()}. Every comment, analysis, recommendation, and report section MUST be written in ${label}. This is NON-NEGOTIABLE.`;
+}
diff --git a/src/frameworks/queue/pQueueAdapter.ts b/src/frameworks/queue/pQueueAdapter.ts
@@ -1,7 +1,8 @@
 import PQueue from 'p-queue';
 import type { Logger } from 'pino';
-import { loadConfig } from '../config/configLoader.js';
-import type { ReviewProgress, ProgressEvent } from '../../entities/progress/progress.type.js';
+import { loadConfig } from '@/frameworks/config/configLoader.js';
+import type { ReviewProgress, ProgressEvent } from '@/entities/progress/progress.type.js';
+import type { Language } from '@/entities/language/language.schema.js';
 
 export interface ReviewJob {
   id: string; // Unique identifier: platform:project:mrNumber
@@ -15,6 +16,8 @@ export interface ReviewJob {
   targetBranch: string;
   // Job type: review or followup
   jobType?: 'review' | 'followup';
+  // Output language for the review
+  language?: Language;
   // Optional MR metadata
   title?: string;
   description?: string;
diff --git a/src/frameworks/settings/runtimeSettings.ts b/src/frameworks/settings/runtimeSettings.ts
@@ -2,14 +2,18 @@
  * Runtime settings that can be changed without restart
  */
 
+import type { Language } from '@/entities/language/language.schema.js';
+
 export type ClaudeModel = 'sonnet' | 'opus';
 
 interface RuntimeSettings {
   model: ClaudeModel;
+  language: Language;
 }
 
 const settings: RuntimeSettings = {
-  model: 'opus', // Default to opus as requested
+  model: 'opus',
+  language: 'en',
 };
 
 export function getModel(): ClaudeModel {
@@ -23,6 +27,14 @@ export function setModel(model: ClaudeModel): void {
   settings.model = model;
 }
 
+export function getDefaultLanguage(): Language {
+  return settings.language;
+}
+
+export function setDefaultLanguage(language: Language): void {
+  settings.language = language;
+}
+
 export function getSettings(): RuntimeSettings {
   return { ...settings };
 }
diff --git a/src/interface-adapters/controllers/http/settings.routes.ts b/src/interface-adapters/controllers/http/settings.routes.ts
@@ -1,5 +1,6 @@
 import type { FastifyPluginAsync } from 'fastify';
-import { getModel, setModel, getSettings, type ClaudeModel } from '../../../frameworks/settings/runtimeSettings.js';
+import { getModel, setModel, getDefaultLanguage, setDefaultLanguage, getSettings, type ClaudeModel } from '@/frameworks/settings/runtimeSettings.js';
+import { languageSchema } from '@/entities/language/language.schema.js';
 
 export const settingsRoutes: FastifyPluginAsync = async (fastify) => {
   fastify.get('/api/settings', async () => {
@@ -23,4 +24,17 @@ export const settingsRoutes: FastifyPluginAsync = async (fastify) => {
     setModel(model);
     return { success: true, model: getModel() };
   });
+
+  fastify.post('/api/settings/language', async (request, reply) => {
+    const { language } = request.body as { language?: string };
+
+    const parsed = languageSchema.safeParse(language);
+    if (!parsed.success) {
+      reply.code(400);
+      return { success: false, error: 'Invalid language. Use: en, fr' };
+    }
+
+    setDefaultLanguage(parsed.data);
+    return { success: true, language: getDefaultLanguage() };
+  });
 };
diff --git a/src/interface-adapters/controllers/webhook/github.controller.ts b/src/interface-adapters/controllers/webhook/github.controller.ts
@@ -23,7 +23,7 @@ import { ReviewContextFileSystemGateway } from '../../gateways/reviewContext.fil
 import { GitHubThreadFetchGateway, defaultGitHubExecutor } from '../../gateways/threadFetch.github.gateway.js';
 import { GitHubDiffMetadataFetchGateway } from '../../gateways/diffMetadataFetch.github.gateway.js';
 import { startWatchingReviewContext, stopWatchingReviewContext } from '../../../main/websocket.js';
-import { getProjectAgents } from '../../../config/projectConfig.js';
+import { getProjectAgents, getProjectLanguage } from '@/config/projectConfig.js';
 import { DEFAULT_AGENTS } from '../../../entities/progress/agentDefinition.type.js';
 
 export async function handleGitHubWebhook(
@@ -185,6 +185,7 @@ export async function handleGitHubWebhook(
     sourceBranch: filterResult.sourceBranch,
     targetBranch: filterResult.targetBranch,
     jobType: 'review',
+    language: getProjectLanguage(repoConfig.localPath),
     title: prTitle,
     description: event.pull_request?.body,
     assignedBy,
diff --git a/src/interface-adapters/controllers/webhook/gitlab.controller.ts b/src/interface-adapters/controllers/webhook/gitlab.controller.ts
@@ -19,7 +19,7 @@ import { RecordPushUseCase } from '../../../usecases/tracking/recordPush.usecase
 import { TransitionStateUseCase } from '../../../usecases/tracking/transitionState.usecase.js';
 import { CheckFollowupNeededUseCase } from '../../../usecases/tracking/checkFollowupNeeded.usecase.js';
 import { SyncThreadsUseCase } from '../../../usecases/tracking/syncThreads.usecase.js';
-import { loadProjectConfig, getProjectAgents, getFollowupAgents } from '../../../config/projectConfig.js';
+import { loadProjectConfig, getProjectAgents, getFollowupAgents, getProjectLanguage } from '@/config/projectConfig.js';
 import { DEFAULT_AGENTS, DEFAULT_FOLLOWUP_AGENTS } from '../../../entities/progress/agentDefinition.type.js';
 import { parseReviewOutput } from '../../../services/statsService.js';
 import { parseThreadActions } from '../../../services/threadActionsParser.js';
@@ -434,6 +434,7 @@ export async function handleGitLabWebhook(
     sourceBranch: filterResult.sourceBranch,
     targetBranch: filterResult.targetBranch,
     jobType: 'review',
+    language: getProjectLanguage(repoConfig.localPath),
     // MR metadata for dashboard
     title: mrTitle,
     description: event.object_attributes?.description,
diff --git a/src/interface-adapters/views/dashboard/index.html b/src/interface-adapters/views/dashboard/index.html
@@ -62,6 +62,15 @@ <h1>Reviewflow</h1>
           </select>
         </div>
       </div>
+      <div class="card">
+        <div class="card-label">Langue</div>
+        <div class="card-model">
+          <select id="language-select" class="model-select" onchange="changeLanguage(this.value)">
+            <option value="en">English</option>
+            <option value="fr">Français</option>
+          </select>
+        </div>
+      </div>
     </div>
 
     <div class="project-loader">
@@ -1240,6 +1249,35 @@ <h1>Reviewflow</h1>
       }
     }
 
+    async function loadLanguageSetting() {
+      try {
+        const response = await fetch(`${API_URL}/api/settings`);
+        const data = await response.json();
+        const select = document.getElementById('language-select');
+        if (select && data.language) {
+          select.value = data.language;
+        }
+      } catch (error) {
+        console.error('Error loading language setting:', error);
+      }
+    }
+
+    async function changeLanguage(language) {
+      try {
+        const response = await fetch(`${API_URL}/api/settings/language`, {
+          method: 'POST',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({ language })
+        });
+        const data = await response.json();
+        if (data.success) {
+          console.log('Language changed to:', language);
+        }
+      } catch (error) {
+        console.error('Error changing language:', error);
+      }
+    }
+
     // Project config loader with persistence
     const STORAGE_KEY_PROJECTS = 'review-flow-projects';
     const STORAGE_KEY_CURRENT = 'review-flow-current-project';
@@ -1511,6 +1549,7 @@ <h1>Reviewflow</h1>
     fetchStatus();
     checkClaudeStatus();
     loadModelSetting();
+    loadLanguageSetting();
     initProjectLoader(); // Will check git CLI and load reviews/stats after loading project config
 
     // Initialize Lucide icons
diff --git a/src/tests/factories/reviewJob.factory.ts b/src/tests/factories/reviewJob.factory.ts
@@ -1,4 +1,4 @@
-import type { ReviewJob } from '../../frameworks/queue/pQueueAdapter.js'
+import type { ReviewJob } from '@/frameworks/queue/pQueueAdapter.js'
 
 export class ReviewJobFactory {
   static create(overrides?: Partial<ReviewJob>): ReviewJob {
@@ -13,6 +13,7 @@ export class ReviewJobFactory {
       sourceBranch: 'feature/test',
       targetBranch: 'main',
       jobType: 'review',
+      language: 'en',
       ...overrides,
     }
   }
diff --git a/src/tests/units/config/projectConfig.test.ts b/src/tests/units/config/projectConfig.test.ts
@@ -0,0 +1,92 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import * as fs from 'node:fs';
+import { loadProjectConfig, getProjectLanguage } from '@/config/projectConfig.js';
+
+vi.mock('node:fs');
+
+describe('loadProjectConfig', () => {
+  beforeEach(() => {
+    vi.resetAllMocks();
+  });
+
+  it('should default language to "en" when not specified', () => {
+    vi.mocked(fs.existsSync).mockReturnValue(true);
+    vi.mocked(fs.readFileSync).mockReturnValue(
+      JSON.stringify({
+        github: true,
+        gitlab: false,
+        defaultModel: 'sonnet',
+        reviewSkill: 'review-front',
+        reviewFollowupSkill: 'review-followup',
+      }),
+    );
+
+    const config = loadProjectConfig('/fake/path');
+
+    expect(config?.language).toBe('en');
+  });
+
+  it('should use "fr" when explicitly specified in config', () => {
+    vi.mocked(fs.existsSync).mockReturnValue(true);
+    vi.mocked(fs.readFileSync).mockReturnValue(
+      JSON.stringify({
+        github: true,
+        gitlab: false,
+        defaultModel: 'sonnet',
+        reviewSkill: 'review-front',
+        reviewFollowupSkill: 'review-followup',
+        language: 'fr',
+      }),
+    );
+
+    const config = loadProjectConfig('/fake/path');
+
+    expect(config?.language).toBe('fr');
+  });
+
+  it('should fall back to "en" for an invalid language value', () => {
+    vi.mocked(fs.existsSync).mockReturnValue(true);
+    vi.mocked(fs.readFileSync).mockReturnValue(
+      JSON.stringify({
+        github: true,
+        gitlab: false,
+        defaultModel: 'sonnet',
+        reviewSkill: 'review-front',
+        reviewFollowupSkill: 'review-followup',
+        language: 'de',
+      }),
+    );
+
+    const config = loadProjectConfig('/fake/path');
+
+    expect(config?.language).toBe('en');
+  });
+});
+
+describe('getProjectLanguage', () => {
+  beforeEach(() => {
+    vi.resetAllMocks();
+  });
+
+  it('should return language from project config', () => {
+    vi.mocked(fs.existsSync).mockReturnValue(true);
+    vi.mocked(fs.readFileSync).mockReturnValue(
+      JSON.stringify({
+        github: true,
+        gitlab: false,
+        defaultModel: 'sonnet',
+        reviewSkill: 'review-front',
+        reviewFollowupSkill: 'review-followup',
+        language: 'fr',
+      }),
+    );
+
+    expect(getProjectLanguage('/fake/path')).toBe('fr');
+  });
+
+  it('should default to "en" when config does not exist', () => {
+    vi.mocked(fs.existsSync).mockReturnValue(false);
+
+    expect(getProjectLanguage('/nonexistent')).toBe('en');
+  });
+});
diff --git a/src/tests/units/entities/language/language.schema.test.ts b/src/tests/units/entities/language/language.schema.test.ts
diff --git a/src/tests/units/frameworks/claude/languageDirective.test.ts b/src/tests/units/frameworks/claude/languageDirective.test.ts
diff --git a/src/tests/units/frameworks/settings/runtimeSettings.test.ts b/src/tests/units/frameworks/settings/runtimeSettings.test.ts
diff --git a/src/tests/units/interface-adapters/controllers/webhook/gitlab.controller.test.ts b/src/tests/units/interface-adapters/controllers/webhook/gitlab.controller.test.ts
diff --git a/src/usecases/triggerReview.usecase.ts b/src/usecases/triggerReview.usecase.ts
