check descriptor before private field access (#12910)

* fix: check descriptor before private field access

* add test cases

packages/babel-helpers/src/helpers.js

@@ -1336,6 +1336,9 @@ helpers.classPrivateFieldSet = helper("7.0.0-beta.0")`
 
 helpers.classPrivateFieldDestructureSet = helper("7.4.4")`
   export default function _classPrivateFieldDestructureSet(receiver, privateMap) {
+    if (privateMap === undefined) {
+      throw new TypeError("attempted to set private static field before its declaration");
+    }
     if (!privateMap.has(receiver)) {
       throw new TypeError("attempted to set private field on non-instance");
     }
@@ -1367,6 +1370,9 @@ helpers.classStaticPrivateFieldSpecGet = helper("7.0.2")`
     if (receiver !== classConstructor) {
       throw new TypeError("Private static access of wrong provenance");
     }
+    if (descriptor === undefined) {
+      throw new TypeError("attempted to get private static field before its declaration");
+    }
     if (descriptor.get) {
       return descriptor.get.call(receiver);
     }
@@ -1379,6 +1385,9 @@ helpers.classStaticPrivateFieldSpecSet = helper("7.0.2")`
     if (receiver !== classConstructor) {
       throw new TypeError("Private static access of wrong provenance");
     }
+    if (descriptor === undefined) {
+      throw new TypeError("attempted to set private static field before its declaration");
+    }
     if (descriptor.set) {
       descriptor.set.call(receiver, value);
     } else {

packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/access-before-declaration/exec.js

@@ -0,0 +1,29 @@
+expect(() => {
+  class C {
+    static #_ = new C;
+    static #p;
+    constructor() {
+      C.#p;
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static #p;
+    constructor() {
+      C.#p = 0;
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static #p;
+    constructor() {
+      for (C.#p of [0]);
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);

packages/babel-plugin-proposal-class-properties/test/fixtures/private/access-before-declaration/exec.js

@@ -0,0 +1,29 @@
+expect(() => {
+  class C {
+    static #_ = new C;
+    static #p;
+    constructor() {
+      C.#p;
+    }
+  }
+}).toThrow(/attempted to get private static field before its declaration/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static #p;
+    constructor() {
+      C.#p = 0;
+    }
+  }
+}).toThrow(/attempted to set private static field before its declaration/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static #p;
+    constructor() {
+      for (C.#p of [0]);
+    }
+  }
+}).toThrow(/attempted to set private static field before its declaration/);

packages/babel-plugin-proposal-private-methods/test/fixtures/static-accessors-loose/access-before-declaration/exec.js

@@ -0,0 +1,29 @@
+expect(() => {
+  class C {
+    static #_ = new C;
+    static get #p() { return C };
+    constructor() {
+      C.#p;
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static set #p(v) {};
+    constructor() {
+      C.#p = 0;
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static set #p(v) {};
+    constructor() {
+      for (C.#p of [0]);
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);

packages/babel-plugin-proposal-private-methods/test/fixtures/static-accessors-privateFieldsAsProperties/access-before-declaration/exec.js

@@ -0,0 +1,29 @@
+expect(() => {
+  class C {
+    static #_ = new C;
+    static get #p() { return C };
+    constructor() {
+      C.#p;
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static set #p(v) {};
+    constructor() {
+      C.#p = 0;
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static set #p(v) {};
+    constructor() {
+      for (C.#p of [0]);
+    }
+  }
+}).toThrow(/attempted to use private field on non-instance/);

packages/babel-plugin-proposal-private-methods/test/fixtures/static-accessors/access-before-declaration/exec.js

@@ -0,0 +1,29 @@
+expect(() => {
+  class C {
+    static #_ = new C;
+    static get #p() { return C };
+    constructor() {
+      C.#p;
+    }
+  }
+}).toThrow(/attempted to get private static field before its declaration/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static set #p(v) {};
+    constructor() {
+      C.#p = 0;
+    }
+  }
+}).toThrow(/attempted to set private static field before its declaration/);
+
+expect(() => {
+  class C {
+    static #_ = new C;
+    static set #p(v) {};
+    constructor() {
+      for (C.#p of [0]);
+    }
+  }
+}).toThrow(/attempted to set private static field before its declaration/);