Fix generated code order when using TypeScript, ES6 and decorators

packages/core/integration-tests/test/integration/typescript-es6-decorators/.parcelrc

@@ -0,0 +1,6 @@
+{
+  "extends": "@parcel/config-default",
+  "transformers": {
+    "*.{ts,tsx}": ["@parcel/transformer-typescript-tsc"]
+  }
+}

packages/core/integration-tests/test/integration/typescript-es6-decorators/index.ts

@@ -0,0 +1,3 @@
+import {ClassOne} from './one';
+
+module.exports = ClassOne.name

packages/core/integration-tests/test/integration/typescript-es6-decorators/one.ts

@@ -0,0 +1,9 @@
+import {ClassTwo} from './two';
+
+function decorator() {
+}
+
+export class ClassOne {
+  @decorator(ClassTwo)
+  two?: ClassTwo;
+}

packages/core/integration-tests/test/integration/typescript-es6-decorators/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "target": "es6"
+  }
+}

packages/core/integration-tests/test/integration/typescript-es6-decorators/two.ts

@@ -0,0 +1,9 @@
+import {ClassOne} from './one';
+
+function decorator() {
+}
+
+export class ClassTwo {
+  @decorator(ClassOne)
+  one?: ClassOne;
+}

packages/core/integration-tests/test/typescript-tsc.js

@@ -56,4 +56,19 @@ describe('typescript tsc', function () {
     let output = await run(b);
     assert.equal(new output.Foo().run(), 'bar');
   });
+
+  it('should support decorators when the target is es6', async () => {
+    const b = await bundle(
+      path.join(__dirname, '/integration/typescript-es6-decorators/index.ts'),
+      {
+        config: path.join(
+          __dirname,
+          '/integration/typescript-es6-decorators/.parcelrc',
+        ),
+      },
+    );
+
+    const output = await run(b);
+    assert.strictEqual(output, 'ClassOne');
+  });
 });

packages/transformers/js/core/src/modules.rs

@@ -22,6 +22,7 @@ pub fn esm2cjs(node: Module, versions: Option<Versions>) -> (Module, bool) {
     interops: HashSet::new(),
     requires: vec![],
     exports: vec![],
+    export_alls: vec![],
     needs_helpers: false,
     in_export_decl: false,
     in_function_scope: false,
@@ -44,6 +45,7 @@ struct ESMFold {
   requires: Vec<ModuleItem>,
   // List of exports to add.
   exports: Vec<ModuleItem>,
+  export_alls: Vec<ModuleItem>,
   needs_helpers: bool,
   in_export_decl: bool,
   in_function_scope: bool,
@@ -398,7 +400,7 @@ impl Fold for ESMFold {
                 ],
                 export.span,
               );
-              self.requires.push(export);
+              self.export_alls.push(export);
             }
             ModuleDecl::ExportDefaultExpr(export) => {
               needs_interop_flag = true;
@@ -527,7 +529,8 @@ impl Fold for ESMFold {
 
     let mut node = node;
     items.splice(0..0, self.requires.clone());
-    items.splice(0..0, self.exports.clone());
+    items.extend_from_slice(&self.exports.clone());
+    items.extend_from_slice(&self.export_alls.clone());
 
     if self.needs_helpers {
       items.insert(