vendorin/src/wasm-loader.js

Vendor ES modules locally from esm.sh CDN - no more node_modules!

import { createRequire } from 'node:module';
import * as fs from 'node:fs/promises';
import { fileURLToPath } from 'node:url';
import { join, dirname } from 'node:path';

import {
  default as init,
  initializeTreeSitter,
  setupParser,
  findNodes,
} from 'ast-grep-wasm';

const { readFile } = fs;

// Create require function for loading CommonJS modules in ESM
const require = createRequire(import.meta.url);

// Mock global require to debug what's being required
if (true) {
  // console.log('🔍 Setting up global require mock for debugging...');
  global.require = function (id) {
    // console.log(`📦 REQUIRE CALL: "${id}"`);
    try {
      if (id === 'fs/promises') {
        // console.log(`✅ REQUIRE REPLACE: "${id}"`);
        return fs;
      }
      const result = require(id);
      // console.log(`✅ REQUIRE SUCCESS: "${id}"`);
      return result;
    } catch (error) {
      // console.log(`❌ REQUIRE FAILED: "${id}" - ${error.message}`);
      throw error;
    }
  };

  // Copy require properties
  Object.setPrototypeOf(global.require, require);
  Object.assign(global.require, require);
}

let isInitialized = false;

/**
 * Resolve WASM file path using Node.js module resolution
 */
function resolveWasmPath(packageName, wasmFile) {
  try {
    // Use require.resolve to find the package
    const packagePath = require.resolve(packageName + '/package.json');
    const packageDir = dirname(packagePath);
    return join(packageDir, wasmFile);
  } catch (error) {
    throw new Error(`Could not resolve WASM file for ${packageName}: ${error.message}`);
  }
}

/**
 * Initialize ast-grep WASM module
 */
export async function initializeAstGrep() {
  if (isInitialized) return;

  try {
    // Resolve WASM files using Node.js module resolution
    const wasmPath = resolveWasmPath('ast-grep-wasm', 'ast_grep_wasm_bg.wasm');
    const jsParserPath = resolveWasmPath('tree-sitter-javascript', 'tree-sitter-javascript.wasm');

    // Read WASM file as buffer and initialize the module
    const wasmBuffer = await readFile(wasmPath);
    await init({ module_or_path: wasmBuffer });

    // Initialize TreeSitter
    await initializeTreeSitter();

    // Setup JavaScript parser
    await setupParser('javascript', jsParserPath);

    isInitialized = true;
    // console.log('✅ ast-grep WASM initialized successfully');
  } catch (error) {
    console.error('❌ Failed to initialize ast-grep WASM:', error);
    throw error;
  }
}

/**
 * Parse JavaScript source code and return root node
 */
export async function transform(source, config) {
  await initializeAstGrep();
  return findNodes(source, [config]);
}