convert to URL for import

lib/createJestRunner.ts

@@ -1,3 +1,5 @@
+import * as path from 'path';
+import * as url from 'url';
 import type { TestResult } from '@jest/test-result';
 import type {
  CallbackTestRunnerInterface,
@@ -36,6 +38,15 @@ export default function createRunner<
  runPath: string,
  { getExtraOptions }: CreateRunnerOptions<ExtraOptions> = {},
 ) {
+ if (!runPath.startsWith('file')) {
+ if (!path.isAbsolute(runPath)) {
+ throw new Error(`Path must be absolute - got ${runPath}`);
+ }
+
+ // eslint-disable-next-line no-param-reassign
+ runPath = url.pathToFileURL(runPath).href;
+ }
+
  return class BaseTestRunner implements CallbackTestRunnerInterface {
  #globalConfig: Config.GlobalConfig;
 
@@ -121,7 +132,7 @@ export default function createRunner<
  onFailure: OnTestFailure,
  options: TestRunnerOptions,
  ): Promise<void> {
- const worker = new Worker(runPath, {
+ const worker = new Worker(url.fileURLToPath(runPath), {
  exposedMethods: ['default'],
  numWorkers: this.#globalConfig.maxWorkers,
  forkOptions: { stdio: 'inherit' },