Fixed computed keys for class expression (#10029)

* test case for insertBefore for jsx

* fix unshiftContainer and insertBefore

* use path.scope.push

* add test making sure computedKeys var declaration at the right block

* add comment

* nit [skip ci]

packages/babel-helper-create-class-features-plugin/src/misc.js

@@ -98,10 +98,16 @@ export function extractComputedKeys(ref, path, computedPaths, file) {
       const ident = path.scope.generateUidIdentifierBasedOnNode(
         computedNode.key,
       );
+      // Declaring in the same block scope
+      // Ref: https://github.com/babel/babel/pull/10029/files#diff-fbbdd83e7a9c998721c1484529c2ce92
+      path.scope.push({
+        id: ident,
+        kind: "let",
+      });
       declarations.push(
-        t.variableDeclaration("var", [
-          t.variableDeclarator(ident, computedNode.key),
-        ]),
+        t.expressionStatement(
+          t.assignmentExpression("=", t.cloneNode(ident), computedNode.key),
+        ),
       );
       computedNode.key = t.cloneNode(ident);
     }

packages/babel-plugin-proposal-class-properties/test/fixtures/nested-class/super-call-in-key/output.js

@@ -16,11 +16,12 @@ function (_Hello) {
   babelHelpers.inherits(Outer, _Hello);
 
   function Outer() {
+    let _this2;
+
     var _this;
 
     babelHelpers.classCallCheck(this, Outer);
-
-    var _this2 = _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Outer).call(this));
+    _this2 = _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Outer).call(this));
 
     let Inner = function Inner() {
       babelHelpers.classCallCheck(this, Inner);

packages/babel-plugin-proposal-class-properties/test/fixtures/nested-class/super-property-in-key/output.js

@@ -22,12 +22,13 @@ function (_Hello) {
   babelHelpers.inherits(Outer, _Hello);
 
   function Outer() {
+    let _babelHelpers$get$cal;
+
     var _this;
 
     babelHelpers.classCallCheck(this, Outer);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Outer).call(this));
-
-    var _babelHelpers$get$cal = babelHelpers.get(babelHelpers.getPrototypeOf(Outer.prototype), "toString", babelHelpers.assertThisInitialized(_this)).call(babelHelpers.assertThisInitialized(_this));
+    _babelHelpers$get$cal = babelHelpers.get(babelHelpers.getPrototypeOf(Outer.prototype), "toString", babelHelpers.assertThisInitialized(_this)).call(babelHelpers.assertThisInitialized(_this));
 
     let Inner = function Inner() {
       babelHelpers.classCallCheck(this, Inner);

packages/babel-plugin-proposal-class-properties/test/fixtures/public-loose/computed/output.js

@@ -1,24 +1,19 @@
+var _one, _ref, _undefined, _computed, _computed2, _ref2, _ref3, _baz, _ref4;
+
 var foo = "foo";
 
 var bar = () => {};
 
 var four = 4;
-
-var _one = one();
-
-var _ref = 2 * four + seven;
-
-var _undefined = undefined;
-
-var _computed = computed();
-
-var _computed2 = computed();
-
-var _ref2 = "test" + one;
-
-var _ref3 = /regex/;
-var _baz = baz;
-var _ref4 = `template${expression}`;
+_one = one();
+_ref = 2 * four + seven;
+_undefined = undefined;
+_computed = computed();
+_computed2 = computed();
+_ref2 = "test" + one;
+_ref3 = /regex/;
+_baz = baz;
+_ref4 = `template${expression}`;
 
 var MyClass =
 /*#__PURE__*/

packages/babel-plugin-proposal-class-properties/test/fixtures/public-loose/instance-computed/output.js

@@ -1,5 +1,7 @@
 function test(x) {
-  var _x = x;
+  var _x;
+
+  _x = x;
 
   var F = function F() {
     "use strict";

packages/babel-plugin-proposal-class-properties/test/fixtures/public/computed-without-block/exec.js

@@ -0,0 +1,5 @@
+const createClass = (k) => class { [k()] = 2 };
+
+const clazz = createClass(() => 'foo');
+const instance = new clazz();
+expect(instance.foo).toBe(2);

packages/babel-plugin-proposal-class-properties/test/fixtures/public/computed-without-block/input.js

@@ -0,0 +1 @@
+const createClass = (k) => class { [k()] = 2 };

packages/babel-plugin-proposal-class-properties/test/fixtures/public/computed-without-block/output.js

@@ -0,0 +1,18 @@
+var createClass = k => {
+  var _temp;
+
+  var _k;
+
+  return _temp = (_k = k(),
+  /*#__PURE__*/
+  function () {
+    "use strict";
+
+    function _class2() {
+      babelHelpers.classCallCheck(this, _class2);
+      babelHelpers.defineProperty(this, _k, 2);
+    }
+
+    return _class2;
+  }()), _temp;
+};

packages/babel-plugin-proposal-class-properties/test/fixtures/public/computed/output.js

@@ -1,24 +1,19 @@
+var _one, _ref, _undefined, _computed, _computed2, _ref2, _ref3, _baz, _ref4;
+
 var foo = "foo";
 
 var bar = () => {};
 
 var four = 4;
-
-var _one = one();
-
-var _ref = 2 * four + seven;
-
-var _undefined = undefined;
-
-var _computed = computed();
-
-var _computed2 = computed();
-
-var _ref2 = "test" + one;
-
-var _ref3 = /regex/;
-var _baz = baz;
-var _ref4 = `template${expression}`;
+_one = one();
+_ref = 2 * four + seven;
+_undefined = undefined;
+_computed = computed();
+_computed2 = computed();
+_ref2 = "test" + one;
+_ref3 = /regex/;
+_baz = baz;
+_ref4 = `template${expression}`;
 
 var MyClass =
 /*#__PURE__*/

packages/babel-plugin-proposal-class-properties/test/fixtures/public/instance-computed/output.js

@@ -1,5 +1,7 @@
 function test(x) {
-  var _x = x;
+  var _x;
+
+  _x = x;
 
   var F = function F() {
     "use strict";

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/7371/output.js

@@ -75,9 +75,11 @@ new ComputedMethod(); // ensure ComputedKey Field is still transformed
 
 class ComputedField extends Obj {
   constructor() {
+    let _ref;
+
     var _temp3;
 
-    var _ref = (_temp3 = super(), babelHelpers.defineProperty(this, "field", 1), _temp3);
+    _ref = (_temp3 = super(), babelHelpers.defineProperty(this, "field", 1), _temp3);
 
     class B extends Obj {
       constructor() {

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/8882/exec.js

@@ -0,0 +1,23 @@
+const classes = [];
+for (let i = 0; i <= 10; ++i) {
+  classes.push(
+    class A {
+      [i] = `computed field ${i}`;
+      static foo = `static field ${i}`;
+      #bar = `private field ${i}`;
+      getBar() {
+        return this.#bar;
+      }
+    }
+  );
+}
+
+for(let i=0; i<= 10; ++i) {
+  const clazz = classes[i];
+  expect(clazz.foo).toBe('static field ' + i);
+
+  const instance = new clazz();
+  expect(Object.getOwnPropertyNames(instance)).toEqual([String(i)])
+  expect(instance[i]).toBe('computed field ' + i);
+  expect(instance.getBar()).toBe('private field ' + i);
+}

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/8882/input.js

@@ -0,0 +1,13 @@
+const classes = [];
+for (let i = 0; i <= 10; ++i) {
+  classes.push(
+    class A {
+      [i] = `computed field ${i}`;
+      static foo = `static field ${i}`;
+      #bar = `private field ${i}`;
+      getBar() {
+        return this.#bar;
+      }
+    }
+  );
+}

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/8882/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["external-helpers", "proposal-class-properties"]
+}

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/8882/output.js

@@ -0,0 +1,23 @@
+const classes = [];
+
+for (let i = 0; i <= 10; ++i) {
+  var _class, _temp, _bar;
+
+  let _i;
+
+  classes.push((_temp = (_i = i, _class = class A {
+    constructor() {
+      babelHelpers.defineProperty(this, _i, `computed field ${i}`);
+
+      _bar.set(this, {
+        writable: true,
+        value: `private field ${i}`
+      });
+    }
+
+    getBar() {
+      return babelHelpers.classPrivateFieldGet(this, _bar);
+    }
+
+  }), _bar = new WeakMap(), babelHelpers.defineProperty(_class, "foo", `static field ${i}`), _temp));
+}

packages/babel-plugin-proposal-class-properties/test/fixtures/static-property-tdz/decorator-interop/output.js

@@ -1,4 +1,6 @@
-var _class, _descriptor, _Symbol$search, _temp;
+let _Symbol$search;
+
+var _class, _descriptor, _temp;
 
 function _initializerDefineProperty(target, property, descriptor, context) { if (!descriptor) return; Object.defineProperty(target, property, { enumerable: descriptor.enumerable, configurable: descriptor.configurable, writable: descriptor.writable, value: descriptor.initializer ? descriptor.initializer.call(context) : void 0 }); }
 

packages/babel-plugin-proposal-class-properties/test/fixtures/static-property-tdz/edgest-case/output.js

@@ -1,10 +1,12 @@
+let _x$x;
+
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
 
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 
 function _classNameTDZError(name) { throw new Error("Class \"" + name + "\" cannot be referenced in computed property keys."); }
 
-var _x$x = {
+_x$x = {
   x: (_classNameTDZError("A"), A) || 0
 }.x;
 

packages/babel-plugin-proposal-class-properties/test/fixtures/static-property-tdz/general/output.js

@@ -1,10 +1,12 @@
+let _ref;
+
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
 
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 
 function _classNameTDZError(name) { throw new Error("Class \"" + name + "\" cannot be referenced in computed property keys."); }
 
-var _ref = (_classNameTDZError("C"), C) + 3;
+_ref = (_classNameTDZError("C"), C) + 3;
 
 let C = function C() {
   "use strict";

packages/babel-plugin-proposal-class-properties/test/fixtures/static-property-tdz/loose/output.js

@@ -1,6 +1,8 @@
+let _ref;
+
 function _classNameTDZError(name) { throw new Error("Class \"" + name + "\" cannot be referenced in computed property keys."); }
 
-var _ref = (_classNameTDZError("C"), C) + 3;
+_ref = (_classNameTDZError("C"), C) + 3;
 
 class C {}
 

packages/babel-traverse/src/path/modification.js

@@ -24,9 +24,7 @@ export function insertBefore(nodes) {
   ) {
     return parentPath.insertBefore(nodes);
   } else if (
-    (this.isNodeType("Expression") &&
-      this.listKey !== "params" &&
-      this.listKey !== "arguments") ||
+    (this.isNodeType("Expression") && !this.isJSXElement()) ||
     (parentPath.isForStatement() && this.key === "init")
   ) {
     if (this.node) nodes.push(this.node);
@@ -220,7 +218,7 @@ export function unshiftContainer(listKey, nodes) {
     key: 0,
   });
 
-  return path.insertBefore(nodes);
+  return path._containerInsertBefore(nodes);
 }
 
 export function pushContainer(listKey, nodes) {

packages/babel-traverse/test/modification.js

@@ -36,6 +36,19 @@ describe("modification", function() {
 
       expect(generateCode(rootPath)).toBe("function test(a) {\n  b;\n}");
     });
+
+    it("properly handles more than one arguments", function() {
+      const code = "foo(a, b);";
+      const ast = parse(code);
+      traverse(ast, {
+        CallExpression: function(path) {
+          path.pushContainer("arguments", t.identifier("d"));
+          expect(generateCode(path)).toBe("foo(a, b, d);");
+          path.pushContainer("arguments", t.stringLiteral("s"));
+          expect(generateCode(path)).toBe(`foo(a, b, d, "s");`);
+        },
+      });
+    });
   });
   describe("unshiftContainer", function() {
     it("unshifts identifier into params", function() {
@@ -116,6 +129,32 @@ describe("modification", function() {
       );
     });
 
+    it("returns inserted path with nested JSXElement", function() {
+      const ast = parse("<div><span>foo</span></div>", {
+        plugins: ["jsx"],
+      });
+      let path;
+      traverse(ast, {
+        Program: function(_path) {
+          path = _path.get("body.0");
+        },
+        JSXElement: function(path) {
+          const tagName = path.node.openingElement.name.name;
+          if (tagName !== "span") return;
+          path.insertBefore(
+            t.JSXElement(
+              t.JSXOpeningElement(t.JSXIdentifier("div"), [], false),
+              t.JSXClosingElement(t.JSXIdentifier("div")),
+              [],
+            ),
+          );
+        },
+      });
+      expect(generateCode(path)).toBe(
+        "<div><div></div><span>foo</span></div>;",
+      );
+    });
+
     describe("when the parent is an export declaration inserts the node before", function() {
       it("the ExportNamedDeclaration", function() {
         const bodyPath = getPath("export function a() {}", {