feat(config): Add TypeScript/JavaScript config file support with defineConfig helper

README.md

@@ -995,12 +995,84 @@ When running as an MCP server, Repomix provides the following tools:
 
 ## ⚙️ Configuration
 
-Create a `repomix.config.json` file in your project root for custom configurations.
+Repomix supports multiple configuration file formats for flexibility and ease of use.
+
+### Configuration File Formats
+
+Repomix will automatically search for configuration files in the following priority order:
+
+1. **TypeScript** (`repomix.config.ts`, `repomix.config.mts`, `repomix.config.cts`)
+2. **JavaScript/ES Module** (`repomix.config.js`, `repomix.config.mjs`, `repomix.config.cjs`)
+3. **JSON** (`repomix.config.json5`, `repomix.config.jsonc`, `repomix.config.json`)
+
+#### JSON Configuration
+
+Create a `repomix.config.json` file in your project root:
 
 ```bash
 repomix --init
 ```
 
+This will create a `repomix.config.json` file with default settings.
+
+#### TypeScript Configuration
+
+TypeScript configuration files provide the best developer experience with full type checking and IDE support.
+
+**Installation:**
+
+To use TypeScript or JavaScript configuration with `defineConfig`, you need to install Repomix as a dev dependency:
+
+```bash
+npm install -D repomix
+```
+
+**Example:**
+
+```typescript
+// repomix.config.ts
+import { defineConfig } from 'repomix';
+
+export default defineConfig({
+  output: {
+    filePath: 'output.xml',
+    style: 'xml',
+    removeComments: true,
+  },
+  ignore: {
+    customPatterns: ['**/node_modules/**', '**/dist/**'],
+  },
+});
+```
+
+**Benefits:**
+- ✅ Full TypeScript type checking in your IDE
+- ✅ Excellent IDE autocomplete and IntelliSense
+- ✅ Use dynamic values (timestamps, environment variables, etc.)
+
+**Dynamic Values Example:**
+
+```typescript
+// repomix.config.ts
+import { defineConfig } from 'repomix';
+
+// Generate timestamp-based filename
+const timestamp = new Date().toISOString().slice(0, 19).replace(/[:.]/g, '-');
+
+export default defineConfig({
+  output: {
+    filePath: `output-${timestamp}.xml`,
+    style: 'xml',
+  },
+});
+```
+
+#### JavaScript Configuration
+
+JavaScript configuration files work the same as TypeScript, supporting `defineConfig` and dynamic values.
+
+### Configuration Options
+
 Here's an explanation of the configuration options:
 
 | Option                           | Description                                                                                                                  | Default                |
@@ -1041,10 +1113,29 @@ The configuration file supports [JSON5](https://json5.org/) syntax, which allows
 - Unquoted property names
 - More relaxed string syntax
 
+### Schema Validation
+
+You can enable schema validation for your configuration file by adding the `$schema` property:
+
+```json
+{
+  "$schema": "https://repomix.com/schemas/latest/schema.json",
+  "output": {
+    "filePath": "repomix-output.xml",
+    "style": "xml"
+  }
+}
+```
+
+This provides auto-completion and validation in editors that support JSON schema.
+
+### Example Configuration
+
 Example configuration:
 
 ```json5
 {
+  "$schema": "https://repomix.com/schemas/latest/schema.json",
   "input": {
     "maxFileSize": 50000000
   },

package.json

@@ -91,6 +91,7 @@
     "handlebars": "^4.7.8",
     "iconv-lite": "^0.7.0",
     "istextorbinary": "^9.5.0",
+    "jiti": "^2.6.1",
     "jschardet": "^3.1.4",
     "json5": "^2.2.3",
     "log-update": "^7.0.1",

repomix.config.ts

@@ -0,0 +1,60 @@
+// Note: Normally you would import from 'repomix', but since this is the repomix project itself,
+// we import directly from the source index file.
+// For your projects, use: import { defineConfig } from 'repomix';
+import { defineConfig } from './src/index.js';
+
+export default defineConfig({
+  input: {
+    maxFileSize: 50000000,
+  },
+  output: {
+    filePath: 'repomix-output.xml',
+    style: 'xml',
+    parsableStyle: false,
+    compress: false,
+    headerText: `This repository contains the source code for the Repomix tool.
+Repomix is designed to pack repository contents into a single file,
+making it easier for AI systems to analyze and process the codebase.
+
+Key Features:
+- Configurable ignore patterns
+- Custom header text support
+- Efficient file processing and packing
+
+Please refer to the README.md file for more detailed information on usage and configuration.
+`,
+    instructionFilePath: 'repomix-instruction.md',
+    fileSummary: true,
+    directoryStructure: true,
+    files: true,
+    removeComments: false,
+    removeEmptyLines: false,
+    topFilesLength: 5,
+    showLineNumbers: false,
+    includeEmptyDirectories: true,
+    truncateBase64: true,
+    // Display token count tree for files/directories with 50000+ tokens
+    // Can be boolean (true/false) or number (minimum token threshold)
+    tokenCountTree: 50000,
+    git: {
+      sortByChanges: true,
+      sortByChangesMaxCommits: 100,
+      includeDiffs: true,
+      includeLogs: true,
+      includeLogsCount: 50,
+    },
+  },
+  include: [],
+  ignore: {
+    useGitignore: true,
+    useDefaultPatterns: true,
+    // ignore is specified in .repomixignore
+    customPatterns: [],
+  },
+  security: {
+    enableSecurityCheck: true,
+  },
+  tokenCount: {
+    encoding: 'o200k_base',
+  },
+});

src/config/configLoad.ts

@@ -1,5 +1,7 @@
 import * as fs from 'node:fs/promises';
 import path from 'node:path';
+import { pathToFileURL } from 'node:url';
+import { createJiti } from 'jiti';
 import JSON5 from 'json5';
 import pc from 'picocolors';
 import { RepomixError, rethrowValidationErrorIfZodError } from '../shared/errorHandle.js';
@@ -15,7 +17,17 @@ import {
 } from './configSchema.js';
 import { getGlobalDirectory } from './globalDirectory.js';
 
-const defaultConfigPaths = ['repomix.config.json5', 'repomix.config.jsonc', 'repomix.config.json'];
+const defaultConfigPaths = [
+  'repomix.config.ts',
+  'repomix.config.mts',
+  'repomix.config.cts',
+  'repomix.config.js',
+  'repomix.config.mjs',
+  'repomix.config.cjs',
+  'repomix.config.json5',
+  'repomix.config.jsonc',
+  'repomix.config.json',
+];
 
 const getGlobalConfigPaths = () => {
   const globalDir = getGlobalDirectory();
@@ -83,15 +95,51 @@ export const loadFileConfig = async (rootDir: string, argConfigPath: string | nu
   return {};
 };
 
+const getFileExtension = (filePath: string): string => {
+  const match = filePath.match(/\.(ts|mts|cts|js|mjs|cjs|json5|jsonc|json)$/);
+  return match ? match[1] : '';
+};
+
 const loadAndValidateConfig = async (filePath: string): Promise<RepomixConfigFile> => {
   try {
-    const fileContent = await fs.readFile(filePath, 'utf-8');
-    const config = JSON5.parse(fileContent);
+    let config: unknown;
+    const ext = getFileExtension(filePath);
+
+    switch (ext) {
+      case 'ts':
+      case 'mts':
+      case 'cts':
+      case 'js':
+      case 'mjs':
+      case 'cjs': {
+        // Use jiti for TypeScript and JavaScript files
+        // This provides consistent behavior and avoids Node.js module cache issues
+        const jiti = createJiti(import.meta.url, {
+          moduleCache: false, // Disable cache to ensure fresh config loads
+          interopDefault: true, // Automatically use default export
+        });
+        config = await jiti.import(pathToFileURL(filePath).href);
+        break;
+      }
+
+      case 'json5':
+      case 'jsonc':
+      case 'json': {
+        // Use JSON5 for JSON/JSON5/JSONC files
+        const fileContent = await fs.readFile(filePath, 'utf-8');
+        config = JSON5.parse(fileContent);
+        break;
+      }
+
+      default:
+        throw new RepomixError(`Unsupported config file format: ${filePath}`);
+    }
+
     return repomixConfigFileSchema.parse(config);
   } catch (error) {
     rethrowValidationErrorIfZodError(error, 'Invalid config schema');
     if (error instanceof SyntaxError) {
-      throw new RepomixError(`Invalid JSON5 in config file ${filePath}: ${error.message}`);
+      throw new RepomixError(`Invalid syntax in config file ${filePath}: ${error.message}`);
     }
     if (error instanceof Error) {
       throw new RepomixError(`Error loading config from ${filePath}: ${error.message}`);

src/config/configSchema.ts

@@ -165,3 +165,6 @@ export type RepomixConfigCli = z.infer<typeof repomixConfigCliSchema>;
 export type RepomixConfigMerged = z.infer<typeof repomixConfigMergedSchema>;
 
 export const defaultConfig = repomixConfigDefaultSchema.parse({});
+
+// Helper function for type-safe config definition
+export const defineConfig = (config: RepomixConfigFile): RepomixConfigFile => config;