fix: add computed property support for object Ref (#10863)

* fix: add computed property support for object Ref

* Apply suggestions from code review

Co-Authored-By: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

* Update output.js

packages/babel-plugin-proposal-object-rest-spread/src/index.js

@@ -102,12 +102,12 @@ export default declare((api, opts) => {
 
   // replaces impure computed keys with new identifiers
   // and returns variable declarators of these new identifiers
-  function replaceImpureComputedKeys(path) {
+  function replaceImpureComputedKeys(properties, scope) {
     const impureComputedPropertyDeclarators = [];
-    for (const propPath of path.get("properties")) {
+    for (const propPath of properties) {
       const key = propPath.get("key");
       if (propPath.node.computed && !key.isPure()) {
-        const name = path.scope.generateUidBasedOnNode(key.node);
+        const name = scope.generateUidBasedOnNode(key.node);
         const declarator = t.variableDeclarator(t.identifier(name), key.node);
         impureComputedPropertyDeclarators.push(declarator);
         key.replaceWith(t.identifier(name));
@@ -139,7 +139,10 @@ export default declare((api, opts) => {
     const restElement = t.cloneNode(last.node);
     last.remove();
 
-    const impureComputedPropertyDeclarators = replaceImpureComputedKeys(path);
+    const impureComputedPropertyDeclarators = replaceImpureComputedKeys(
+      path.get("properties"),
+      path.scope,
+    );
     const { keys, allLiteral } = extractNormalizedKeys(path);
 
     if (keys.length === 0) {
@@ -265,18 +268,21 @@ export default declare((api, opts) => {
 
           path.findParent(path => {
             if (path.isObjectProperty()) {
-              refPropertyPath.unshift(path.node.key.name);
+              refPropertyPath.unshift(path);
             } else if (path.isVariableDeclarator()) {
               kind = path.parentPath.node.kind;
               return true;
             }
           });
 
-          if (refPropertyPath.length) {
+          const impureObjRefComputedDeclarators = replaceImpureComputedKeys(
-            refPropertyPath.forEach(prop => {
+            refPropertyPath,
-              ref = t.memberExpression(ref, t.identifier(prop));
+            path.scope,
-            });
+          );
-          }
+          refPropertyPath.forEach(prop => {
+            const { node } = prop;
+            ref = t.memberExpression(ref, t.cloneNode(node.key), node.computed);
+          });
 
           const objectPatternPath = path.findParent(path =>
             path.isObjectPattern(),
@@ -296,6 +302,8 @@ export default declare((api, opts) => {
 
           insertionPath.insertBefore(impureComputedPropertyDeclarators);
 
+          insertionPath.insertBefore(impureObjRefComputedDeclarators);
+
           insertionPath.insertAfter(
             t.variableDeclarator(argument, callExpression),
           );

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-rest/object-ref-computed-exec/exec.js

@@ -0,0 +1,20 @@
+var key, x, y, z;
+// impure
+key = 1;
+var { [key++]: { y, ...x } } = { 1: { a: 1, y: 1 } };
+expect(x).toEqual({ a: 1 });
+expect(key).toBe(2);
+expect(y).toBe(1);
+
+// takes care of the order
+
+key = 1;
+var {
+  [++key]: { y, ...rest_y },
+  [++key]: { z, ...rest_z }
+} = {2: { y: 2, z: 3 }, 3: { y: 2, z: 3 } };
+expect(y).toBe(2);
+expect(rest_y).toEqual({z: 3});
+expect(z).toBe(3);
+expect(rest_z).toEqual({ y: 2 });
+expect(key).toBe(3);

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-rest/object-ref-computed/input.js

@@ -0,0 +1,20 @@
+var key, x, y, z;
+// impure
+key = 1;
+var { [key++]: { y, ...x } } = { 1: { a: 1, y: 1 } };
+expect(x).toEqual({ a: 1 });
+expect(key).toBe(2);
+expect(y).toBe(1);
+
+// takes care of the order
+
+key = 1;
+var {
+  [++key]: { y, ...rest_y },
+  [++key]: { z, ...rest_z }
+} = {2: { y: 2, z: 3 }, 3: { y: 2, z: 3 } };
+expect(y).toBe(2);
+expect(rest_y).toEqual({z: 3});
+expect(z).toBe(3);
+expect(rest_z).toEqual({ y: 2 });
+expect(key).toBe(3);

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-rest/object-ref-computed/output.js

@@ -0,0 +1,62 @@
+var key, x, y, z; // impure
+
+key = 1;
+
+var _ref = key++,
+    {
+  [_ref]: {
+    y
+  }
+} = {
+  1: {
+    a: 1,
+    y: 1
+  }
+},
+    x = babelHelpers.objectWithoutProperties({
+  1: {
+    a: 1,
+    y: 1
+  }
+}[_ref], ["y"]);
+
+expect(x).toEqual({
+  a: 1
+});
+expect(key).toBe(2);
+expect(y).toBe(1); // takes care of the order
+
+key = 1;
+
+var _$ = {
+  2: {
+    y: 2,
+    z: 3
+  },
+  3: {
+    y: 2,
+    z: 3
+  }
+},
+    _ref2 = ++key,
+    _ref3 = ++key,
+    {
+  [_ref3]: {
+    y
+  },
+  [_ref2]: {
+    z
+  }
+} = _$,
+    rest_y = babelHelpers.objectWithoutProperties(_$[_ref3], ["y"]),
+    rest_z = babelHelpers.objectWithoutProperties(_$[_ref2], ["z"]);
+
+expect(y).toBe(2);
+expect(rest_y).toEqual({
+  z: 3
+});
+expect(z).toBe(3);
+expect(rest_z).toEqual({
+  y: 2
+});
+expect(key).toBe(3);