Fix 5768 (#5811)

* Fix destructured exports

- adds a failing test based on description in #5768
- handles ObjectPattern and ArrayPattern

* use export assignment template

packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js

@@ -75,23 +75,53 @@ export default function () {
       if (node[REASSIGN_REMAP_SKIP]) return;
 
       const left = path.get("left");
-      if (!left.isIdentifier()) return;
+      if (left.isIdentifier()) {
+        const name = left.node.name;
+        const exports = this.exports[name];
+        if (!exports) return;
 
-      const name = left.node.name;
-      const exports = this.exports[name];
-      if (!exports) return;
+        // redeclared in this scope
+        if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
 
-      // redeclared in this scope
-      if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
+        node[REASSIGN_REMAP_SKIP] = true;
 
-      node[REASSIGN_REMAP_SKIP] = true;
+        for (const reid of exports) {
+          node = buildExportsAssignment(reid, node).expression;
+        }
 
-      for (const reid of exports) {
-        node = buildExportsAssignment(reid, node).expression;
+        path.replaceWith(node);
+        this.requeueInParent(path);
       }
+      else if (left.isObjectPattern()) {
+        for (const property of left.node.properties) {
+          const name = property.value.name;
 
-      path.replaceWith(node);
-      this.requeueInParent(path);
+          const exports = this.exports[name];
+          if (!exports) continue;
+
+          // redeclared in this scope
+          if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
+
+          node[REASSIGN_REMAP_SKIP] = true;
+
+          path.insertAfter(buildExportsAssignment(t.identifier(name), t.identifier(name)));
+        }
+      }
+      else if (left.isArrayPattern()) {
+        for (const element of left.node.elements) {
+          const name = element.name;
+
+          const exports = this.exports[name];
+          if (!exports) continue;
+
+          // redeclared in this scope
+          if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
+
+          node[REASSIGN_REMAP_SKIP] = true;
+
+          path.insertAfter(buildExportsAssignment(t.identifier(name), t.identifier(name)));
+        }
+      }
     },
 
     UpdateExpression(path) {

packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-destructured/actual.js

@@ -0,0 +1,14 @@
+export let x = 0;
+export let y = 0;
+
+export function f1 () {
+  ({x} = { x: 1 });
+}
+
+export function f2 () {
+  ({x, y} = { x: 2, y: 3 });
+}
+
+export function f3 () {
+  [x, y, z] = [3, 4, 5]
+}

packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-destructured/expected.js

@@ -0,0 +1,27 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.f1 = f1;
+exports.f2 = f2;
+exports.f3 = f3;
+let x = exports.x = 0;
+let y = exports.y = 0;
+
+function f1() {
+  ({ x } = { x: 1 });
+  exports.x = x;
+}
+
+function f2() {
+  ({ x, y } = { x: 2, y: 3 });
+  exports.y = y;
+  exports.x = x;
+}
+
+function f3() {
+  [x, y, z] = [3, 4, 5];
+  exports.y = y;
+  exports.x = x;
+}