From 7abdd241612b0f2608ae21000a980d15f8cb878b Mon Sep 17 00:00:00 2001
From: Tiger Oakes <contact@tigeroakes.com>
Date: Mon, 2 Mar 2020 11:18:27 -0800
Subject: [PATCH] test(typescript): Add preserveModules test

---
 .../test/fixtures/preserve-modules/main.ts          |  7 +++++++
 .../test/fixtures/preserve-modules/tsconfig.json    | 11 +++++++++++
 packages/typescript/test/test.js                    | 13 +++++++++++++
 3 files changed, 31 insertions(+)
 create mode 100644 packages/typescript/test/fixtures/preserve-modules/main.ts
 create mode 100644 packages/typescript/test/fixtures/preserve-modules/tsconfig.json

diff --git a/packages/typescript/test/fixtures/preserve-modules/main.ts b/packages/typescript/test/fixtures/preserve-modules/main.ts
new file mode 100644
index 000000000..281b086d4
--- /dev/null
+++ b/packages/typescript/test/fixtures/preserve-modules/main.ts
@@ -0,0 +1,7 @@
+/* eslint-disable */
+const b = () => {
+  const a = { a: 1, b: 2 };
+  console.log({ ...a });
+};
+
+export { b };
diff --git a/packages/typescript/test/fixtures/preserve-modules/tsconfig.json b/packages/typescript/test/fixtures/preserve-modules/tsconfig.json
new file mode 100644
index 000000000..7a570de4e
--- /dev/null
+++ b/packages/typescript/test/fixtures/preserve-modules/tsconfig.json
@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "allowSyntheticDefaultImports": true,
+    "downlevelIteration": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "module": "esnext",
+    "strict": true,
+    "target": "es5"
+  }
+}
diff --git a/packages/typescript/test/test.js b/packages/typescript/test/test.js
index 0da0b48c1..b8f63dd85 100644
--- a/packages/typescript/test/test.js
+++ b/packages/typescript/test/test.js
@@ -589,6 +589,19 @@ test('should throw on bad options', async (t) => {
   ]);
 });
 
+test('creates _tslib.js file when preserveModules is used', async (t) => {
+  const bundle = await rollup({
+    input: 'fixtures/preserve-modules/main.ts',
+    plugins: [typescript({ tsconfig: 'fixtures/preserve-modules/tsconfig.json' })],
+    preserveModules: true,
+    onwarn
+  });
+
+  const files = await getCode(bundle, { format: 'es' }, true);
+  t.true(files[0].fileName.includes('main.js'), files[0].fileName);
+  t.true(files[1].fileName.includes('tslib.es6.js'), files[1].fileName);
+});
+
 test('should handle re-exporting types', async (t) => {
   const bundle = await rollup({
     input: 'fixtures/reexport-type/main.ts',