Add test

packages/core/integration-tests/package.json

@@ -54,6 +54,7 @@
     "sugarss": "^3.0.3",
     "tailwindcss": "^3.0.2",
     "tempy": "^0.3.0",
+    "wasm-sourcemap": "^1.0.0",
     "ws": "^7.0.0"
   }
 }

packages/core/integration-tests/test/integration/wasm-sourcemap-transformer/.parcelrc

@@ -0,0 +1,6 @@
+{
+  "extends": "@parcel/config-default",
+  "transformers": {
+    "*.wasm": ["parcel-transformer-test"]
+  }
+}

packages/core/integration-tests/test/integration/wasm-sourcemap-transformer/index.js

@@ -0,0 +1 @@
+console.log(new URL("index.wasm", import.meta.url))

packages/core/integration-tests/test/plugin.js

@@ -15,6 +15,8 @@ import {
   overlayFS,
   run,
 } from '@parcel/test-utils';
+import * as wasmmap from 'wasm-sourcemap';
+import {relativePath} from '@parcel/utils';
 
 describe('plugin', function () {
   it("continue transformer pipeline on type change that doesn't change the pipeline", async function () {
@@ -310,4 +312,21 @@ parcel-transformer-b`,
     await assertAsset('const replaced = 1;');
     await assertAsset('const replaced = 2;');
   });
+
+  it('should output sourcemaps when packaging Wasm', async () => {
+    let b = await bundle(
+      path.join(__dirname, '/integration/wasm-sourcemap-transformer/index.js'),
+    );
+    let wasmPath = nullthrows(
+      b.getBundles().find(b => b.type === 'wasm'),
+    ).filePath;
+    let mapPath = wasmPath + '.map';
+    assert(await fs.exists(mapPath));
+
+    let wasm = await fs.readFile(wasmPath);
+    assert.equal(
+      wasmmap.GetSourceMapURL(wasm),
+      relativePath(distDir, mapPath, false),
+    );
+  });
 });

yarn.lock

@@ -14120,6 +14120,11 @@ w3c-xmlserializer@^3.0.0:
   dependencies:
     xml-name-validator "^4.0.0"
 
+wasm-sourcemap@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/wasm-sourcemap/-/wasm-sourcemap-1.0.0.tgz#c9aa3a2105eb2f15b838687b5aebeac4e0c9a07c"
+  integrity sha512-IiOoUHnsI6bVVbs8Q+JO6cj7KtxwGiiS5nJGDbZXfj6srbIDzjjbZk9WMAusvynTzzlPlMgJhb/4SGz92ZgXsA==
+
 wcwidth@^1.0.0, wcwidth@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/wcwidth/-/wcwidth-1.0.1.tgz#f0b0dcf915bc5ff1528afadb2c0e17b532da2fe8"