fix: Deleting super property should throw

packages/babel-helper-replace-supers/package.json

@@ -20,6 +20,12 @@
     "@babel/traverse": "workspace:^",
     "@babel/types": "workspace:^"
   },
+  "peerDependencies": {
+    "@babel/core": "^7.0.0-0"
+  },
+  "devDependencies": {
+    "@babel/core": "workspace:^"
+  },
   "engines": {
     "node": ">=6.9.0"
   },

packages/babel-helper-replace-supers/src/index.ts

@@ -1,9 +1,11 @@
-import type { NodePath, Scope } from "@babel/traverse";
-import traverse from "@babel/traverse";
+import { template } from "@babel/core";
+import type { File } from "@babel/core";
+import environmentVisitor from "@babel/helper-environment-visitor";
 import memberExpressionToFunctions from "@babel/helper-member-expression-to-functions";
 import type { HandlerState } from "@babel/helper-member-expression-to-functions";
 import optimiseCall from "@babel/helper-optimise-call-expression";
-import environmentVisitor from "@babel/helper-environment-visitor";
+import traverse from "@babel/traverse";
+import type { NodePath, Scope } from "@babel/traverse";
 import {
   assignmentExpression,
   booleanLiteral,
@@ -16,7 +18,6 @@ import {
   thisExpression,
 } from "@babel/types";
 import type * as t from "@babel/types";
-import type { File } from "@babel/core";
 
 // TODO (Babel 8): Don't export this.
 export {
@@ -64,6 +65,26 @@ const visitor = traverse.visitors.merge<
     Super(path, state) {
       const { node, parentPath } = path;
       if (!parentPath.isMemberExpression({ object: node })) return;
+      if (parentPath.parentPath.isUnaryExpression({ operator: "delete" })) {
+        const deletePath = parentPath.parentPath;
+        if (parentPath.node.computed) {
+          deletePath.replaceWith(
+            sequenceExpression([
+              callExpression(this.file.addHelper("toPropertyKey"), [
+                cloneNode(parentPath.node.property as t.Expression),
+              ]),
+              template.expression.ast`
+                function () { throw new ReferenceError("'delete super[expr]' is invalid"); }()
+              `,
+            ]),
+          );
+        } else {
+          deletePath.replaceWith(template.expression.ast`
+            function () { throw new ReferenceError("'delete super.prop' is invalid"); }()
+          `);
+        }
+        return;
+      }
       state.handle(parentPath);
     },
   },

packages/babel-plugin-transform-classes/test/fixtures/regression/15169/exec.js

@@ -0,0 +1,3 @@
+expect(() => {
+  class x { static y = delete super[0]; }
+}).toThrow(ReferenceError);

packages/babel-plugin-transform-classes/test/fixtures/regression/15169/input.js

@@ -0,0 +1 @@
+class x { static y = delete super[0]; }

packages/babel-plugin-transform-classes/test/fixtures/regression/15169/output.js

@@ -0,0 +1,8 @@
+var x = /*#__PURE__*/babelHelpers.createClass(function x() {
+  "use strict";
+
+  babelHelpers.classCallCheck(this, x);
+});
+babelHelpers.defineProperty(x, "y", (babelHelpers.toPropertyKey(0), function () {
+  throw new ReferenceError("'delete super[expr]' is invalid");
+}()));

packages/babel-plugin-transform-classes/test/fixtures/spec/delete-super-property-to-property-key/exec.js

@@ -0,0 +1,23 @@
+// [Symbol.toPrimitive] must be called if exist
+var counter = 0;
+expect(() => {
+  (new class {
+    f() {
+      delete super[{
+        [Symbol.toPrimitive]: function() { ++counter; return 0; },
+      }];
+    }
+  }).f();
+}).toThrow(ReferenceError);
+expect(counter).toBe(1);
+
+// [Symbol.toPrimitive] must return a primitive value
+expect(() => {
+  (new class {
+    f() {
+      delete super[{
+        [Symbol.toPrimitive]: function() { return {}; },
+      }];
+    }
+  }).f();
+}).toThrow(TypeError);

packages/babel-plugin-transform-classes/test/fixtures/spec/delete-super-property-to-property-key/input.js

@@ -0,0 +1,18 @@
+// [Symbol.toPrimitive] must be called if exist
+var counter = 0;
+(new class {
+  f() {
+    delete super[{
+      [Symbol.toPrimitive]: function() { ++counter; return 0; },
+    }];
+  }
+}).f();
+
+// [Symbol.toPrimitive] must return a primitive value
+(new class {
+  f() {
+    delete super[{
+      [Symbol.toPrimitive]: function() { return {}; },
+    }];
+  }
+}).f();

packages/babel-plugin-transform-classes/test/fixtures/spec/delete-super-property-to-property-key/output.js

@@ -0,0 +1,45 @@
+// [Symbol.toPrimitive] must be called if exist
+var counter = 0;
+new ( /*#__PURE__*/function () {
+  "use strict";
+
+  function _class() {
+    babelHelpers.classCallCheck(this, _class);
+  }
+  babelHelpers.createClass(_class, [{
+    key: "f",
+    value: function f() {
+      babelHelpers.toPropertyKey({
+        [Symbol.toPrimitive]: function () {
+          ++counter;
+          return 0;
+        }
+      }), function () {
+        throw new ReferenceError("'delete super[expr]' is invalid");
+      }();
+    }
+  }]);
+  return _class;
+}())().f();
+
+// [Symbol.toPrimitive] must return a primitive value
+new ( /*#__PURE__*/function () {
+  "use strict";
+
+  function _class2() {
+    babelHelpers.classCallCheck(this, _class2);
+  }
+  babelHelpers.createClass(_class2, [{
+    key: "f",
+    value: function f() {
+      babelHelpers.toPropertyKey({
+        [Symbol.toPrimitive]: function () {
+          return {};
+        }
+      }), function () {
+        throw new ReferenceError("'delete super[expr]' is invalid");
+      }();
+    }
+  }]);
+  return _class2;
+}())().f();

packages/babel-plugin-transform-classes/test/fixtures/spec/delete-super-property/exec.js

@@ -0,0 +1,27 @@
+expect(() => {
+  (new class {
+    f() { delete super.x; }
+  }).f();
+}).toThrow(ReferenceError);
+
+expect(() => {
+  (new class {
+    f() { delete super[0]; }
+  }).f();
+}).toThrow(ReferenceError);
+
+// [expr] should be evaluated
+var counter = 0;
+expect(() => {
+  (new class {
+    f() { delete super[++counter]; }
+  }).f();
+}).toThrow(ReferenceError);
+expect(counter).toBe(1);
+
+// TypeError before ReferenceError
+expect(() => {
+  (new class {
+    f() { delete super[0()]; }
+  }).f();
+}).toThrow(TypeError);

packages/babel-plugin-transform-classes/test/fixtures/spec/delete-super-property/input.js

@@ -0,0 +1,18 @@
+(new class {
+  f() { delete super.x; }
+}).f();
+
+(new class {
+  f() { delete super[0]; }
+}).f();
+
+// [expr] should be evaluated
+var counter = 0;
+(new class {
+  f() { delete super[++counter]; }
+}).f();
+
+// TypeError before ReferenceError
+(new class {
+  f() { delete super[0()]; }
+}).f();

packages/babel-plugin-transform-classes/test/fixtures/spec/delete-super-property/output.js

@@ -0,0 +1,69 @@
+new ( /*#__PURE__*/function () {
+  "use strict";
+
+  function _class() {
+    babelHelpers.classCallCheck(this, _class);
+  }
+  babelHelpers.createClass(_class, [{
+    key: "f",
+    value: function f() {
+      (function () {
+        throw new ReferenceError("'delete super.prop' is invalid");
+      })();
+    }
+  }]);
+  return _class;
+}())().f();
+new ( /*#__PURE__*/function () {
+  "use strict";
+
+  function _class2() {
+    babelHelpers.classCallCheck(this, _class2);
+  }
+  babelHelpers.createClass(_class2, [{
+    key: "f",
+    value: function f() {
+      babelHelpers.toPropertyKey(0), function () {
+        throw new ReferenceError("'delete super[expr]' is invalid");
+      }();
+    }
+  }]);
+  return _class2;
+}())().f();
+
+// [expr] should be evaluated
+var counter = 0;
+new ( /*#__PURE__*/function () {
+  "use strict";
+
+  function _class3() {
+    babelHelpers.classCallCheck(this, _class3);
+  }
+  babelHelpers.createClass(_class3, [{
+    key: "f",
+    value: function f() {
+      babelHelpers.toPropertyKey(++counter), function () {
+        throw new ReferenceError("'delete super[expr]' is invalid");
+      }();
+    }
+  }]);
+  return _class3;
+}())().f();
+
+// TypeError before ReferenceError
+new ( /*#__PURE__*/function () {
+  "use strict";
+
+  function _class4() {
+    babelHelpers.classCallCheck(this, _class4);
+  }
+  babelHelpers.createClass(_class4, [{
+    key: "f",
+    value: function f() {
+      babelHelpers.toPropertyKey(0()), function () {
+        throw new ReferenceError("'delete super[expr]' is invalid");
+      }();
+    }
+  }]);
+  return _class4;
+}())().f();

yarn.lock

@@ -879,11 +879,14 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@babel/helper-replace-supers@workspace:packages/babel-helper-replace-supers"
   dependencies:
+    "@babel/core": "workspace:^"
     "@babel/helper-environment-visitor": "workspace:^"
     "@babel/helper-member-expression-to-functions": "workspace:^"
     "@babel/helper-optimise-call-expression": "workspace:^"
     "@babel/traverse": "workspace:^"
     "@babel/types": "workspace:^"
+  peerDependencies:
+    "@babel/core": ^7.0.0-0
   languageName: unknown
   linkType: soft