Method loadEsmModule

packages/jest-runtime/src/internals/EsmLoader.ts:962–1084

(
    modulePath: string,
    query = '',
  )

  }

  private async loadEsmModule(
    modulePath: string,
    query = '',
  ): Promise<ESModule> {
    // Two gates here. `supportsSyncEvaluate` is a Node-version check: the
    // sync core relies on `SyntheticModule` starting `'linked'` and on
    // `evaluate()` completing sync, both of which need v22.21+ / v24.8+.
    // `canResolveSync` is a configured-resolver check: with an async-only
    // user resolver `findNodeModule` silently falls back to the default
    // resolver and would silently miss user mappings.
    if (supportsSyncEvaluate && this.resolution.canResolveSync()) {
      const synced = this.tryLoadGraphSync(modulePath, query, 'sync-preferred');
      if (synced) return synced;
    }

    const cacheKey = modulePath + query;
    const registry = this.registries.getActiveEsmRegistry();

    if (this.transformCache.hasMutex(cacheKey)) {
      await this.transformCache.awaitMutex(cacheKey);
    }

    if (!registry.has(cacheKey)) {
      const context = this.getContext();

      let transformResolve: () => void;
      let transformReject: (error?: unknown) => void;

      this.transformCache.setMutex(
        cacheKey,
        new Promise((resolve, reject) => {
          transformResolve = resolve;
          transformReject = reject;
        }),
      );

      invariant(
        transformResolve! && transformReject!,
        'Promise initialization should be sync - please report this bug to Jest!',
      );

      try {
        if (isWasm(modulePath)) {
          const wasm = this.importWasmModule(
            this.fileCache.readFileBuffer(modulePath),
            modulePath,
            context,
          );
          registry.set(cacheKey, wasm);
          transformResolve();
          return wasm;
        }

        if (this.resolution.isCoreModule(modulePath)) {
          const core = evaluateSyntheticModule(
            buildCoreSyntheticModule(modulePath, context, (name, prefix) =>
              this.coreModule.require(name, prefix),
            ),