fix: do not copy extra translations to the build

Author: AleksandrSl

cmp/compiler/README.md

@@ -28,75 +28,81 @@ pnpm add @lingo.dev/compiler
 yarn add @lingo.dev/compiler
 ```
 
-## Quick Start
+## Structure
 
-## Usage with Turbopack (Next.js 16+)
+The compiler is organized into several key modules:
 
-### 1. Configure Next.js
+### Core Directories
 
-[//]: # ( TODO (AleksandrSl 12/12/2025):
+#### `src/plugin/` - Build-time transformation
 
-### 2. (Optional) Use directive mode
+- **`transform/`** - Babel AST transformation logic for JSX text extraction
+- **`unplugin.ts`** - Universal plugin implementation (Vite, Webpack, Rollup, esbuild)
+- **`next.ts`** - Next.js-specific plugin with Turbopack and webpack support
+- **`build-translator.ts`** - Batch translation generation at build time
+- **`locale-code-generator.ts`** - Generates locale resolver modules
 
-If you set `useDirective: true`, add the directive to files you want to translate:
+#### `src/metadata/` - Translation metadata management
 
-```tsx
-"use i18n";
+- **`manager.ts`** - CRUD operations for `.lingo/metadata.json`
+- Thread-safe metadata file operations with locking
+- Manages translation entries with hash-based identifiers
 
-export function MyComponent() {
-  return <div>This text will be translated</div>;
-}
-```
+#### `src/translators/` - Translation provider abstraction
 
-### 3. Write components normally
-
-```tsx
-// src/components/Welcome.tsx
-export function Welcome() {
-  return (
-    <div>
-      <h1>Welcome to our site</h1>
-      <p>This text will be automatically translated</p>
-    </div>
-  );
-}
-```
+- **`lcp/`** - Lingo.dev Engine integration
+- **`pseudotranslator/`** - Development-mode fake translator
+- **`pluralization/`** - Automatic ICU MessageFormat detection
+- **`translator-factory.ts`** - Provider selection and initialization
 
-### 4. Build and see transformations
+#### `src/translation-server/` - Development server
 
-After build, the code will be transformed to:
+- **`translation-server.ts`** - HTTP server for on-demand translations
+- **`cli.ts`** - Standalone CLI for translation generation
+- WebSocket support for real-time dev widget updates
+- Port management (60000-60099 range)
 
-```tsx
-import { useTranslation } from "@lingo.dev/runtime";
+#### `src/react/` - Runtime translation hooks
 
-export function Welcome() {
-  const t = useTranslation();
-  return (
-    <div>
-      <h1>{t("a1b2c3d4e5f6")}</h1>
-      <p>{t("f6e5d4c3b2a1")}</p>
-    </div>
-  );
-}
-```
+- **`client/`** - Client-side Context-based hooks
+- **`server/`** - Server component cache-based hooks (isomorphic)
+- **`server-only/`** - Async server-only API (`getServerTranslations`)
+- **`shared/`** - Shared utilities (RichText rendering, Context)
+- **`next/`** - Next.js-specific middleware and locale switcher
+
+#### `src/utils/` - Shared utilities
+
+- **`hash.ts`** - Stable hash generation for translation keys
+- **`config-factory.ts`** - Configuration defaults and merging
+- **`logger.ts`** - Structured logging utilities
+- **`path-helpers.ts`** - File path resolution
+
+#### `src/widget/` - Development widget
+
+- In-browser translation editor overlay for development mode
+
+### Support Directories
+
+#### `tests/` - End-to-end testing
 
-## How It Works
+- **`e2e/`** - Playwright tests for full build workflows
+- **`fixtures/`** - Test applications (Vite, Next.js)
+- **`helpers/`** - Test utilities and assertions
 
-[//]: # ( TODO (AleksandrSl 12/12/2025):
+#### `benchmarks/` - Performance benchmarks
 
-## Limitations (Current Version)
+- Translation speed benchmarks
+- Metadata I/O performance tests
 
-- Requires manual runtime setup (TranslationProvider, etc.)
+#### `old-docs/` - Legacy documentation
 
-## Supported Bundlers
+- Historical design documents and notes
 
-| Bundler | Status          | Import Path                   |
-| ------- | --------------- | ----------------------------- |
-| Vite    | ✅ Full Support | `@lingo.dev/compiler/vite`    |
-| Webpack | ✅ Full Support | `@lingo.dev/compiler/webpack` |
-| Next.js | ✅ Full Support | `@lingo.dev/compiler/next`    |
+### Entry Points
 
-All bundler plugins share the same configuration API.
+- **`src/index.ts`** - Main package exports (plugins, types)
+- **`src/types.ts`** - Core TypeScript types
+- **`src/dev-config.ts`** - Development configuration utilities
 
 ## Contributing
 

cmp/compiler/src/plugin/build-translator.ts

@@ -89,7 +89,7 @@ export async function processBuildTranslations(
     logger.info("✅ Cache validation passed");
 
     if (publicOutputPath) {
-      await copyStaticFiles(config, publicOutputPath);
+      await copyStaticFiles(config, publicOutputPath, metadata);
     }
 
     return {
@@ -161,7 +161,7 @@ export async function processBuildTranslations(
 
     // Copy cache to public directory if requested
     if (publicOutputPath) {
-      await copyStaticFiles(config, publicOutputPath);
+      await copyStaticFiles(config, publicOutputPath, metadata);
     }
 
     logger.info("✅ Translation generation completed successfully");
@@ -269,11 +269,15 @@ function buildCacheStats(
 async function copyStaticFiles(
   config: LingoConfig,
   publicOutputPath: string,
+  metadata: MetadataSchema,
 ): Promise<void> {
   logger.info(`📦 Generating static translation files in ${publicOutputPath}`);
 
   await fs.mkdir(publicOutputPath, { recursive: true });
 
+  const usedHashes = new Set(Object.keys(metadata.entries));
+  logger.info(`📊 Filtering translations to ${usedHashes.size} used hash(es)`);
+
   // Include source locale if pluralization is enabled
   const needsSourceLocale = config.pluralization?.enabled !== false;
   const allLocales = needsSourceLocale
@@ -285,10 +289,42 @@ async function copyStaticFiles(
     const publicFilePath = path.join(publicOutputPath, `${locale}.json`);
 
     try {
-      await fs.copyFile(cacheFilePath, publicFilePath);
-      logger.info(`✓ Generated ${locale}.json`);
+      const cacheContent = await fs.readFile(cacheFilePath, "utf-8");
+      const cache = JSON.parse(cacheContent);
+
+      const filteredEntries: Record<string, string> = {};
+      let includedCount = 0;
+      let skippedCount = 0;
+
+      for (const [hash, translation] of Object.entries(
+        cache.entries as Record<string, string>,
+      )) {
+        if (usedHashes.has(hash)) {
+          filteredEntries[hash] = translation;
+          includedCount++;
+        } else {
+          skippedCount++;
+        }
+      }
+
+      // Write filtered translations
+      const outputData = {
+        locale,
+        entries: filteredEntries,
+        version: cache.version,
+      };
+
+      await fs.writeFile(
+        publicFilePath,
+        JSON.stringify(outputData, null, 2),
+        "utf-8",
+      );
+
+      logger.info(
+        `✓ Generated ${locale}.json (${includedCount} translations, ${skippedCount} unused skipped)`,
+      );
     } catch (error) {
-      logger.error(`❌ Failed to copy ${locale}.json:`, error);
+      logger.error(`❌ Failed to generate ${locale}.json:`, error);
       process.exit(1);
     }
   }

cmp/compiler/src/plugin/transform/index.ts

@@ -12,23 +12,9 @@ export interface TransformResult {
   transformed: boolean;
 }
 
-/**
- * Options for the Babel transformation
- */
 export interface BabelTransformOptions {
-  /**
-   * Source code to transform
-   */
   code: string;
-
-  /**
-   * File path being transformed
-   */
   filePath: string;
-
-  /**
-   * Loader configuration
-   */
   config: LingoConfig;
 }
 
@@ -86,27 +72,3 @@ export function transformComponent({
     };
   }
 }
-
-/**
- * Check if a file should be transformed
- */
-export function shouldTransformFile(
-  filePath: string,
-  config: LingoConfig,
-): boolean {
-  // Only transform .tsx and .jsx files
-  if (!filePath.match(/\.(tsx|jsx)$/)) {
-    return false;
-  }
-
-  // Check skip patterns
-  if (config.skipPatterns) {
-    for (const pattern of config.skipPatterns) {
-      if (pattern.test(filePath)) {
-        return false;
-      }
-    }
-  }
-
-  return true;
-}

cmp/compiler/src/types.ts

@@ -28,7 +28,7 @@ export interface CookieConfig {
 export type LocalePersistenceConfig = { type: "cookie"; cookieName?: string };
 
 /**
- * Field that we require users to fill in in the config. The rest could be taken from defaults.
+ * Field that we require users to fill in the config. The rest could be taken from defaults.
  */
 export type LingoConfigRequiredFields = "sourceLocale" | "targetLocales";