Private class methods stage 3 (#8654)

* Add private method syntax support

* Add private method spec support

* Add private method loose support

* Throw error if static private method is used

* Add more isStatic & isMethod checks

* Remove `writable:false` from private method inits

`writable` is false by default.

* Add private method func obj equality check

* Throw if private accessor is used

* Add check for fields === private method loose mode

* Throw buildCodeFrameErrors instead of Errors

* Move obj destructuring inside for loop

* Remove "computed" from ClassPrivateMethod type def

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/assignment/exec.js

@@ -0,0 +1,11 @@
+class Foo {
+    constructor() {
+      this.publicField = this.#privateMethod();
+    }
+
+    #privateMethod() {
+      return 42;
+    }
+  }
+
+  expect((new Foo).publicField).toEqual(42);

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/assignment/input.js

@@ -0,0 +1,9 @@
+class Foo {
+  constructor() {
+    this.publicField = this.#privateMethod();
+  }
+
+  #privateMethod() {
+    return 42;
+  }
+}

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/assignment/output.js

@@ -0,0 +1,15 @@
+var Foo = function Foo() {
+  "use strict";
+
+  babelHelpers.classCallCheck(this, Foo);
+  Object.defineProperty(this, _privateMethod, {
+    value: _privateMethod2
+  });
+  this.publicField = babelHelpers.classPrivateFieldLooseBase(this, _privateMethod)[_privateMethod]();
+};
+
+var _privateMethod = babelHelpers.classPrivateFieldLooseKey("privateMethod");
+
+var _privateMethod2 = function _privateMethod2() {
+  return 42;
+};

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/context/exec.js

@@ -0,0 +1,41 @@
+class Foo {
+    constructor(status) {
+      this.status = status;
+      expect(() => this.#getStatus = null).toThrow(TypeError);
+    }
+
+    #getStatus() {
+      return this.status;
+    }
+
+    getCurrentStatus() {
+      return this.#getStatus();
+    }
+
+    setCurrentStatus(newStatus) {
+      this.status = newStatus;
+    }
+
+    getFakeStatus(fakeStatus) {
+      const getStatus = this.#getStatus;
+      return function () {
+        return getStatus.call({ status: fakeStatus });
+      };
+    }
+
+    getFakeStatusFunc() {
+      return {
+        status: 'fake-status',
+        getFakeStatus: this.#getStatus,
+      };
+    }
+  }
+
+  const f = new Foo('inactive');
+  expect(f.getCurrentStatus()).toBe('inactive');
+
+  f.setCurrentStatus('new-status');
+  expect(f.getCurrentStatus()).toBe('new-status');
+
+  expect(f.getFakeStatus('fake')()).toBe('fake');
+  expect(f.getFakeStatusFunc().getFakeStatus()).toBe('fake-status');

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/context/input.js

@@ -0,0 +1,31 @@
+class Foo {
+  constructor(status) {
+    this.status = status;
+  }
+
+  #getStatus() {
+    return this.status;
+  }
+
+  getCurrentStatus() {
+    return this.#getStatus();
+  }
+
+  setCurrentStatus(newStatus) {
+    this.status = newStatus;
+  }
+
+  getFakeStatus(fakeStatus) {
+    const fakeGetStatus = this.#getStatus;
+    return function() {
+      return fakeGetStatus.call({ status: fakeStatus });
+    };
+  }
+
+  getFakeStatusFunc() {
+    return {
+      status: 'fake-status',
+      getFakeStatus: this.#getStatus,
+    };
+  }
+}

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/context/output.js

@@ -0,0 +1,51 @@
+var Foo =
+/*#__PURE__*/
+function () {
+  "use strict";
+
+  function Foo(status) {
+    babelHelpers.classCallCheck(this, Foo);
+    Object.defineProperty(this, _getStatus, {
+      value: _getStatus2
+    });
+    this.status = status;
+  }
+
+  babelHelpers.createClass(Foo, [{
+    key: "getCurrentStatus",
+    value: function getCurrentStatus() {
+      return babelHelpers.classPrivateFieldLooseBase(this, _getStatus)[_getStatus]();
+    }
+  }, {
+    key: "setCurrentStatus",
+    value: function setCurrentStatus(newStatus) {
+      this.status = newStatus;
+    }
+  }, {
+    key: "getFakeStatus",
+    value: function getFakeStatus(fakeStatus) {
+      var fakeGetStatus = babelHelpers.classPrivateFieldLooseBase(this, _getStatus)[_getStatus];
+
+      return function () {
+        return fakeGetStatus.call({
+          status: fakeStatus
+        });
+      };
+    }
+  }, {
+    key: "getFakeStatusFunc",
+    value: function getFakeStatusFunc() {
+      return {
+        status: 'fake-status',
+        getFakeStatus: babelHelpers.classPrivateFieldLooseBase(this, _getStatus)[_getStatus]
+      };
+    }
+  }]);
+  return Foo;
+}();
+
+var _getStatus = babelHelpers.classPrivateFieldLooseKey("getStatus");
+
+var _getStatus2 = function _getStatus2() {
+  return this.status;
+};

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/exfiltrated/exec.js

@@ -0,0 +1,15 @@
+let exfiltrated;
+class Foo {
+    #privateMethod() {}
+
+    constructor() {
+        if (exfiltrated === undefined) {
+            exfiltrated = this.#privateMethod;
+        }
+        expect(exfiltrated).toStrictEqual(this.#privateMethod);
+    }
+}
+
+new Foo();
+// check for private method function object equality
+new Foo();

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/exfiltrated/input.js

@@ -0,0 +1,10 @@
+let exfiltrated;
+class Foo {
+    #privateMethod() {}
+
+    constructor() {
+        if (exfiltrated === undefined) {
+            exfiltrated = this.#privateMethod;
+        }
+    }
+}

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/exfiltrated/output.js

@@ -0,0 +1,18 @@
+var exfiltrated;
+
+var Foo = function Foo() {
+  "use strict";
+
+  babelHelpers.classCallCheck(this, Foo);
+  Object.defineProperty(this, _privateMethod, {
+    value: _privateMethod2
+  });
+
+  if (exfiltrated === undefined) {
+    exfiltrated = babelHelpers.classPrivateFieldLooseBase(this, _privateMethod)[_privateMethod];
+  }
+};
+
+var _privateMethod = babelHelpers.classPrivateFieldLooseKey("privateMethod");
+
+var _privateMethod2 = function _privateMethod2() {};

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method-loose/options.json

@@ -0,0 +1,15 @@
+{
+  "plugins": [
+    [
+      "external-helpers",
+      {
+        "helperVersion": "7.1.6"
+      }
+    ],
+    ["proposal-private-methods", { "loose": true }],
+    ["proposal-class-properties", { "loose": true }],
+    "transform-classes",
+    "transform-block-scoping",
+    "syntax-class-properties"
+  ]
+}

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/assignment/exec.js

@@ -0,0 +1,11 @@
+class Foo {
+    constructor() {
+      this.publicField = this.#privateMethod();
+    }
+  
+    #privateMethod() {
+      return 42;
+    }
+  }
+  
+  expect((new Foo).publicField).toEqual(42);

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/assignment/input.js

@@ -0,0 +1,9 @@
+class Foo {
+  constructor() {
+    this.publicField = this.#privateMethod();
+  }
+
+  #privateMethod() {
+    return 42;
+  }
+}

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/assignment/output.js

@@ -0,0 +1,15 @@
+var Foo = function Foo() {
+  "use strict";
+
+  babelHelpers.classCallCheck(this, Foo);
+
+  _privateMethod.add(this);
+
+  this.publicField = babelHelpers.classPrivateMethodGet(this, _privateMethod, _privateMethod2).call(this);
+};
+
+var _privateMethod = new WeakSet();
+
+var _privateMethod2 = function _privateMethod2() {
+  return 42;
+};

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/context/exec.js

@@ -0,0 +1,41 @@
+class Foo {
+    constructor(status) {
+      this.status = status;
+      expect(() => this.#getStatus = null).toThrow(TypeError);
+    }
+
+    #getStatus() {
+      return this.status;
+    }
+
+    getCurrentStatus() {
+      return this.#getStatus();
+    }
+
+    setCurrentStatus(newStatus) {
+      this.status = newStatus;
+    }
+
+    getFakeStatus(fakeStatus) {
+      const getStatus = this.#getStatus;
+      return function () {
+        return getStatus.call({ status: fakeStatus });
+      };
+    }
+
+    getFakeStatusFunc() {
+      return {
+        status: 'fake-status',
+        getFakeStatus: this.#getStatus,
+      };
+    }
+  }
+
+  const f = new Foo('inactive');
+  expect(f.getCurrentStatus()).toBe('inactive');
+
+  f.setCurrentStatus('new-status');
+  expect(f.getCurrentStatus()).toBe('new-status');
+
+  expect(f.getFakeStatus('fake')()).toBe('fake');
+  expect(f.getFakeStatusFunc().getFakeStatus()).toBe('fake-status');

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/context/input.js

@@ -0,0 +1,31 @@
+class Foo {
+  constructor(status) {
+    this.status = status;
+  }
+
+  #getStatus() {
+    return this.status;
+  }
+
+  getCurrentStatus() {
+    return this.#getStatus();
+  }
+
+  setCurrentStatus(newStatus) {
+    this.status = newStatus;
+  }
+
+  getFakeStatus(fakeStatus) {
+    const fakeGetStatus = this.#getStatus;
+    return function() {
+      return fakeGetStatus.call({ status: fakeStatus });
+    };
+  }
+
+  getFakeStatusFunc() {
+    return {
+      status: 'fake-status',
+      getFakeStatus: this.#getStatus,
+    };
+  }
+}

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/context/output.js

@@ -0,0 +1,50 @@
+var Foo =
+/*#__PURE__*/
+function () {
+  "use strict";
+
+  function Foo(status) {
+    babelHelpers.classCallCheck(this, Foo);
+
+    _getStatus.add(this);
+
+    this.status = status;
+  }
+
+  babelHelpers.createClass(Foo, [{
+    key: "getCurrentStatus",
+    value: function getCurrentStatus() {
+      return babelHelpers.classPrivateMethodGet(this, _getStatus, _getStatus2).call(this);
+    }
+  }, {
+    key: "setCurrentStatus",
+    value: function setCurrentStatus(newStatus) {
+      this.status = newStatus;
+    }
+  }, {
+    key: "getFakeStatus",
+    value: function getFakeStatus(fakeStatus) {
+      var fakeGetStatus = babelHelpers.classPrivateMethodGet(this, _getStatus, _getStatus2);
+      return function () {
+        return fakeGetStatus.call({
+          status: fakeStatus
+        });
+      };
+    }
+  }, {
+    key: "getFakeStatusFunc",
+    value: function getFakeStatusFunc() {
+      return {
+        status: 'fake-status',
+        getFakeStatus: babelHelpers.classPrivateMethodGet(this, _getStatus, _getStatus2)
+      };
+    }
+  }]);
+  return Foo;
+}();
+
+var _getStatus = new WeakSet();
+
+var _getStatus2 = function _getStatus2() {
+  return this.status;
+};

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/exfiltrated/exec.js

@@ -0,0 +1,15 @@
+let exfiltrated;
+class Foo {
+    #privateMethod() {}
+
+    constructor() {
+        if (exfiltrated === undefined) {
+            exfiltrated = this.#privateMethod;
+        }
+        expect(exfiltrated).toStrictEqual(this.#privateMethod);
+    }
+}
+
+new Foo();
+// check for private method function object equality
+new Foo();

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/exfiltrated/input.js

@@ -0,0 +1,10 @@
+let exfiltrated;
+class Foo {
+    #privateMethod() {}
+
+    constructor() {
+        if (exfiltrated === undefined) {
+            exfiltrated = this.#privateMethod;
+        }
+    }
+}

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/exfiltrated/output.js

@@ -0,0 +1,17 @@
+var exfiltrated;
+
+var Foo = function Foo() {
+  "use strict";
+
+  babelHelpers.classCallCheck(this, Foo);
+
+  _privateMethod.add(this);
+
+  if (exfiltrated === undefined) {
+    exfiltrated = babelHelpers.classPrivateMethodGet(this, _privateMethod, _privateMethod2);
+  }
+};
+
+var _privateMethod = new WeakSet();
+
+var _privateMethod2 = function _privateMethod2() {};

packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/options.json

@@ -0,0 +1,15 @@
+{
+  "plugins": [
+    [
+      "external-helpers",
+      {
+        "helperVersion": "7.1.6"
+      }
+    ],
+    "proposal-private-methods",
+    "proposal-class-properties",
+    "transform-classes",
+    "transform-block-scoping",
+    "syntax-class-properties"
+  ]
+}

packages/babel-plugin-proposal-private-methods/test/index.js

@@ -0,0 +1,3 @@
+import runner from "@babel/helper-plugin-test-runner";
+
+runner(__dirname);