fix #596: toString for transform input

lib/browser.ts

@@ -82,12 +82,14 @@ export const startService: typeof types.startService = options => {
         new Promise<types.BuildResult>((resolve, reject) =>
           service.buildOrServe(null, options, false, (err, res) =>
             err ? reject(err) : resolve(res as types.BuildResult))),
-      transform: (input, options) =>
-        new Promise((resolve, reject) =>
+      transform: (input, options) => {
+        input += '';
+        return new Promise((resolve, reject) =>
           service.transform(input, options || {}, false, {
             readFile(_, callback) { callback(new Error('Internal error'), null); },
             writeFile(_, callback) { callback(null); },
-          }, (err, res) => err ? reject(err) : resolve(res!))),
+          }, (err, res) => err ? reject(err) : resolve(res!)))
+      },
       serve() {
         throw new Error(`The "serve" API only works in node`)
       },

lib/common.ts

@@ -728,7 +728,7 @@ export function createChannel(streamIn: StreamIn): StreamOut {
               command: 'transform',
               flags,
               inputFS: inputPath !== null,
-              input: inputPath !== null ? inputPath : input + '',
+              input: inputPath !== null ? inputPath : input,
             };
             sendRequest<protocol.TransformRequest, protocol.TransformResponse>(request, (error, response) => {
               if (error) return callback(new Error(error), null);
@@ -774,7 +774,7 @@ export function createChannel(streamIn: StreamIn): StreamOut {
             });
           }
         };
-        if (typeof input === 'string' && input.length > 1024 * 1024) {
+        if (input.length > 1024 * 1024) {
           let next = start;
           start = () => fs.writeFile(input, next);
         }

lib/node.ts

@@ -100,6 +100,7 @@ export let serve: typeof types.serve = (serveOptions, buildOptions) => {
 };
 
 export let transform: typeof types.transform = (input, options) => {
+  input += '';
   return startService().then(service => {
     let promise = service.transform(input, options);
     promise.then(service.stop, service.stop);
@@ -124,6 +125,8 @@ export let buildSync: typeof types.buildSync = (options: types.BuildOptions): an
 };
 
 export let transformSync: typeof types.transformSync = (input, options) => {
+  input += '';
+
   // Try using a long-lived worker thread to avoid repeated start-up overhead
   if (worker_threads) {
     if (!workerThreadService) workerThreadService = startWorkerThreadService(worker_threads);
@@ -195,8 +198,9 @@ export let startService: typeof types.startService = options => {
         service.buildOrServe(serveOptions, buildOptions, isTTY(), (err, res) =>
           err ? reject(err) : resolve(res as types.ServeResult)))
     },
-    transform: (input, options) =>
-      new Promise((resolve, reject) =>
+    transform: (input, options) => {
+      input += '';
+      return new Promise((resolve, reject) =>
         service.transform(input, options || {}, isTTY(), {
           readFile(tempFile, callback) {
             try {
@@ -220,7 +224,8 @@ export let startService: typeof types.startService = options => {
               callback(null);
             }
           },
-        }, (err, res) => err ? reject(err) : resolve(res!))),
+        }, (err, res) => err ? reject(err) : resolve(res!)));
+    },
     stop() { child.kill(); },
   });
 };

scripts/js-api-tests.js

@@ -1383,6 +1383,21 @@ async function futureSyntax(service, js, targetBelow, targetAbove) {
 }
 
 let transformTests = {
+  async transformWithNonString({ esbuild, service }) {
+    for (let toTest of [esbuild, service]) {
+      try {
+        // Do not "await" here. The error should be thrown outside of the promise.
+        toTest.transform({ toString() { throw new Error('toString() error') } })
+        throw new Error('Expected an error to be thrown');
+      } catch (e) {
+        assert.strictEqual(e.message, 'toString() error')
+      }
+
+      var { code } = await toTest.transform(Buffer.from(`1+2`))
+      assert.strictEqual(code, `1 + 2;\n`)
+    }
+  },
+
   async version({ esbuild }) {
     const version = fs.readFileSync(path.join(repoDir, 'version.txt'), 'utf8').trim()
     assert.strictEqual(esbuild.version, version);
@@ -2156,6 +2171,18 @@ let syncTests = {
     assert.strictEqual(map, '')
   },
 
+  async transformSyncWithNonString({ esbuild }) {
+    try {
+      esbuild.transformSync({ toString() { throw new Error('toString() error') } })
+      throw new Error('Expected an error to be thrown');
+    } catch (e) {
+      assert.strictEqual(e.message, 'toString() error')
+    }
+
+    var { code } = await esbuild.transformSync(Buffer.from(`1+2`))
+    assert.strictEqual(code, `1 + 2;\n`)
+  },
+
   async transformSync100x({ esbuild }) {
     for (let i = 0; i < 100; i++) {
       const { code } = esbuild.transformSync(`console.log(1+${i})`, {})