test(typescript): code in src sub-directory

packages/typescript/test/fixtures/src-dir/src/index.ts

@@ -0,0 +1,69 @@
+type FormDataMap = Map<string, string[]>;
+
+class ReadOnlyFormData {
+  map: FormDataMap;
+
+  constructor(map: FormDataMap) {
+    this.map = map;
+  }
+
+  get(key: string) {
+    return this.map.get(key)?.[0];
+  }
+
+  getAll(key: string) {
+    return this.map.get(key);
+  }
+
+  has(key: string) {
+    return this.map.has(key);
+  }
+
+  *[Symbol.iterator]() {
+    for (const [key, value] of this.map) {
+      for (let i = 0; i < value.length; i += 1) {
+        yield [key, value[i]];
+      }
+    }
+  }
+
+  *entries() {
+    for (const [key, value] of this.map) {
+      for (let i = 0; i < value.length; i += 1) {
+        yield [key, value[i]];
+      }
+    }
+  }
+
+  *keys() {
+    for (const [key, value] of this.map) {
+      for (let i = 0; i < value.length; i += 1) {
+        yield key;
+      }
+    }
+  }
+
+  *values() {
+    for (const [, value] of this.map) {
+      for (let i = 0; i < value.length; i += 1) {
+        yield value;
+      }
+    }
+  }
+}
+
+export default function() {
+  const map: FormDataMap = new Map();
+
+  return {
+    append(key: string, value: string) {
+      if (map.has(key)) {
+        (map.get(key) as string[]).push(value);
+      } else {
+        map.set(key, [value]);
+      }
+    },
+
+    data: new ReadOnlyFormData(map)
+  };
+}

packages/typescript/test/fixtures/src-dir/tsconfig.json

@@ -0,0 +1,24 @@
+{
+  "compilerOptions": {
+    "lib": ["es2020"],
+    "outDir": "dist",
+    "target": "es2020",
+
+    "skipLibCheck": true,
+    "declaration": true,
+
+    "noEmitOnError": true,
+    "noErrorTruncation": true,
+
+    "module": "esnext",
+    "moduleResolution": "node",
+    "resolveJsonModule": true,
+    "allowSyntheticDefaultImports": true,
+
+    "strict": true,
+    "noImplicitThis": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true
+  },
+  "exclude": ["node_modules"]
+}

packages/typescript/test/test.js

@@ -1181,6 +1181,34 @@ test.serial('picks up on newly included typescript files in watch mode', async (
   t.true(usage, 'should contain usage');
 });
 
+// TODO: upgrade TypeScript when there is a release containing the fix for this issue
+// https://github.com/microsoft/TypeScript/pull/41811. Then enable this test
+// More details at https://github.com/rollup/plugins/issues/287. This fails with the message:
+// Unexpected token (Note that you need plugins to import files that are not JavaScript)
+test.serial.skip('works when code is in src directory', async (t) => {
+  const bundle = await rollup({
+    input: 'fixtures/src-dir/src/index.ts',
+    output: [
+      {
+        dir: 'fixtures/src-dir/dist',
+        format: 'esm'
+      }
+    ],
+    plugins: [
+      typescript({
+        tsconfig: 'fixtures/src-dir/tsconfig.json'
+      })
+    ],
+    onwarn
+  });
+  const output = await getCode(bundle, { format: 'esm', dir: 'fixtures/src-dir/dist' }, true);
+
+  t.deepEqual(
+    output.map((out) => out.fileName),
+    ['index.js', 'types/index.d.ts', 'types/index.d.ts.map']
+  );
+});
+
 function waitForWatcherEvent(watcher, eventCode) {
   return new Promise((resolve, reject) => {
     watcher.on('event', function handleEvent(event) {