hack a "fix"

Author: SimenB

packages/babel-plugin-jest-hoist/src/__tests__/__snapshots__/hoistPlugin.test.ts.snap

@@ -1,5 +1,42 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`babel-plugin-jest-hoist automatic react runtime: automatic react runtime 1`] = `
+
+jest.mock('./App', () => () => <div>Hello world</div>);
+
+      ↓ ↓ ↓ ↓ ↓ ↓
+
+_getJestObj().mock("./App", () => () =>
+  /*#__PURE__*/ _jsxDEV(
+    "div",
+    {
+      children: "Hello world"
+    },
+    void 0,
+    false,
+    {
+      fileName: _jsxFileName,
+      lineNumber: 1,
+      columnNumber: 32
+    },
+    this
+  )
+);
+
+import { jsxDEV as _jsxDEV } from "react/jsx-dev-runtime";
+var _jsxFileName = "";
+
+function _getJestObj() {
+  const { jest } = require("@jest/globals");
+
+  _getJestObj = () => jest;
+
+  return jest;
+}
+
+
+`;
+
 exports[`babel-plugin-jest-hoist top level mocking: top level mocking 1`] = `
 
 require('x');

packages/babel-plugin-jest-hoist/src/__tests__/hoistPlugin.test.ts

@@ -23,7 +23,7 @@ pluginTester({
         ],
       },
       code: `
-        jest.mock('./App', () => () => <div>Hello world</div>, {virtual: true});
+        jest.mock('./App', () => () => <div>Hello world</div>);
       `,
       snapshot: true,
     },

packages/babel-plugin-jest-hoist/src/index.ts

@@ -120,41 +120,45 @@ FUNCTIONS.mock = args => {
     moduleFactory.traverse(IDVisitor, {ids});
     for (const id of ids) {
       const {name} = id.node;
-      let found = false;
       let scope = id.scope;
 
       while (scope !== parentScope) {
         if (scope.bindings[name]) {
-          found = true;
-          break;
+          return true;
         }
 
         scope = scope.parent;
       }
 
-      if (!found) {
-        const isAllowedIdentifier =
-          (scope.hasGlobal(name) && ALLOWED_IDENTIFIERS.has(name)) ||
-          /^mock/i.test(name) ||
-          // Allow istanbul's coverage variable to pass.
-          /^(?:__)?cov/.test(name);
-
-        if (!isAllowedIdentifier) {
-          throw id.buildCodeFrameError(
-            'The module factory of `jest.mock()` is not allowed to ' +
-              'reference any out-of-scope variables.\n' +
-              'Invalid variable access: ' +
-              name +
-              '\n' +
-              'Allowed objects: ' +
-              Array.from(ALLOWED_IDENTIFIERS).join(', ') +
-              '.\n' +
-              'Note: This is a precaution to guard against uninitialized mock ' +
-              'variables. If it is ensured that the mock is required lazily, ' +
-              'variable names prefixed with `mock` (case insensitive) are permitted.\n',
-            ReferenceError,
-          );
-        }
+      const binding = scope.bindings[name];
+
+      // @ts-expect-error `init` does not exist
+      if (binding?.constant && scope.isPure(binding.path.node.init, true)) {
+        // how to hoist???
+        return true;
+      }
+
+      const isAllowedIdentifier =
+        (scope.hasGlobal(name) && ALLOWED_IDENTIFIERS.has(name)) ||
+        /^mock/i.test(name) ||
+        // Allow istanbul's coverage variable to pass.
+        /^(?:__)?cov/.test(name);
+
+      if (!isAllowedIdentifier) {
+        throw id.buildCodeFrameError(
+          'The module factory of `jest.mock()` is not allowed to ' +
+            'reference any out-of-scope variables.\n' +
+            'Invalid variable access: ' +
+            name +
+            '\n' +
+            'Allowed objects: ' +
+            Array.from(ALLOWED_IDENTIFIERS).join(', ') +
+            '.\n' +
+            'Note: This is a precaution to guard against uninitialized mock ' +
+            'variables. If it is ensured that the mock is required lazily, ' +
+            'variable names prefixed with `mock` (case insensitive) are permitted.\n',
+          ReferenceError,
+        );
       }
     }