fix: refactor _importCoreModule so required core module is consistent (…

…#15517)

CHANGELOG.md

@@ -83,6 +83,7 @@
 - `[@jest/expect-utils]` Fix not addressing to Sets and Maps as objects without keys ([#14873](https://github.com/jestjs/jest/pull/14873))
 - `[jest-leak-detector]` Make leak-detector more aggressive when running GC ([#14526](https://github.com/jestjs/jest/pull/14526))
 - `[jest-runtime]` Properly handle re-exported native modules in ESM via CJS ([#14589](https://github.com/jestjs/jest/pull/14589))
+- `[jest-runtime]` Refactor `_importCoreModel` so required core module is consistent if modified while loading ([#15077](https://github.com/jestjs/jest/issues/15077))
 - `[jest-schemas, jest-types]` [**BREAKING**] Fix type of `testFailureExitCode` config option([#15232](https://github.com/jestjs/jest/pull/15232))
 - `[jest-util]` Make sure `isInteractive` works in a browser ([#14552](https://github.com/jestjs/jest/pull/14552))
 - `[pretty-format]` [**BREAKING**] Print `ArrayBuffer` and `DataView` correctly ([#14290](https://github.com/jestjs/jest/pull/14290))

packages/jest-runtime/src/index.ts

@@ -1782,13 +1782,15 @@ export default class Runtime {
 
   private _importCoreModule(moduleName: string, context: VMContext) {
     const required = this._requireCoreModule(moduleName, true);
+    const allExports = Object.entries(required);
+    const exportNames = allExports.map(([key]) => key);
 
     const module = new SyntheticModule(
-      ['default', ...Object.keys(required)],
+      ['default', ...exportNames],
       function () {
         // @ts-expect-error: TS doesn't know what `this` is
         this.setExport('default', required);
-        for (const [key, value] of Object.entries(required)) {
+        for (const [key, value] of allExports) {
           // @ts-expect-error: TS doesn't know what `this` is
           this.setExport(key, value);
         }