build(web): relocate source files in WASM sourcemap

Author: amaanq

lib/binding_web/script/build.js

@@ -1,24 +1,67 @@
 import esbuild from 'esbuild';
 import fs from 'fs/promises';
+import path from 'path';
 
 const format = process.env.CJS ? 'cjs' : 'esm';
 const debug = process.argv.includes('--debug');
 const outfile = `${debug ? 'debug/' : ''}tree-sitter.${format === 'esm' ? 'js' : 'cjs'}`;
 
-await esbuild.build({
-  entryPoints: ['src/index.ts'],
-  bundle: true,
-  platform: 'node',
-  format,
-  outfile,
-  sourcemap: true,
-  sourcesContent: true,
-  keepNames: true,
-  external: ['fs/*', 'fs/promises'],
-  resolveExtensions: ['.ts', '.js', format === 'esm' ? '.mjs' : '.cjs'],
-});
-
-// Copy the generated WASM files to the appropriate spot, as esbuild doesn't "bundle" WASM files
-const outputWasmName = `${debug ? 'debug/' : ''}tree-sitter.wasm`;
-await fs.copyFile(`lib/tree-sitter.wasm`, outputWasmName);
-await fs.copyFile(`lib/tree-sitter.wasm.map`, `${outputWasmName}.map`);
+// Copy source files to lib directory - we'll map the wasm's sourecmap to these files.
+async function copySourceFiles() {
+  const sourceDir = '../src';
+  const files = await fs.readdir(sourceDir);
+
+  for (const file of files) {
+    if (file.endsWith('.c') || file.endsWith('.h')) {
+      await fs.copyFile(
+        path.join(sourceDir, file),
+        path.join('lib', file)
+      );
+    }
+  }
+}
+
+async function processWasmSourceMap(inputPath, outputPath) {
+  const mapContent = await fs.readFile(inputPath, 'utf8');
+  const sourceMap = JSON.parse(mapContent);
+
+  // Filter out emscripten files and normalize paths
+  sourceMap.sources = sourceMap.sources
+    .filter(source => {
+      // Keep only tree-sitter source files
+      return source.includes('../../src/') || source === 'tree-sitter.c';
+    })
+    .map(source => {
+      if (source.includes('../../src/')) {
+        return source.replace('../../src/', 'lib/');
+      }
+      return source;
+    });
+
+  await fs.writeFile(outputPath, JSON.stringify(sourceMap, null, 2));
+}
+
+
+async function build() {
+  await esbuild.build({
+    entryPoints: ['src/index.ts'],
+    bundle: true,
+    platform: 'node',
+    format,
+    outfile,
+    sourcemap: true,
+    sourcesContent: true,
+    keepNames: true,
+    external: ['fs/*', 'fs/promises'],
+    resolveExtensions: ['.ts', '.js', format === 'esm' ? '.mjs' : '.cjs'],
+  });
+
+  // Copy the WASM files to the appropriate spot, as esbuild doesn't "bundle" WASM files
+  const outputWasmName = `${debug ? 'debug/' : ''}tree-sitter.wasm`;
+  await fs.copyFile('lib/tree-sitter.wasm', outputWasmName);
+
+  await copySourceFiles();
+  await processWasmSourceMap('lib/tree-sitter.wasm.map', `${outputWasmName}.map`);
+}
+
+build().catch(console.error);