Use async

jest.config.ts

@@ -1,49 +1,51 @@
 import fs from 'node:fs';
 import path from 'node:path';
 
-import { JestConfigWithTsJest } from 'ts-jest';
-
-// Fix some bad package.json files that don't play well with ts-jest
-[
-  // https://github.com/g-plane/cue/issues/1
-  '@gplane/cue',
-].forEach((moduleName) => {
-  const modulePath = path.join('node_modules', moduleName);
-  const packagePath = path.join(modulePath, 'package.json');
-  const packageJson = JSON.parse(fs.readFileSync(packagePath).toString());
-
-  packageJson.main = packageJson.main ?? packageJson.exports['.'].import;
-  delete packageJson.exports;
-
-  fs.writeFileSync(packagePath, JSON.stringify(packageJson, undefined, 2));
-});
-
-const jestConfig: JestConfigWithTsJest = {
-  preset: 'ts-jest',
-  testEnvironment: 'node',
-
-  setupFilesAfterEnv: ['jest-extended/all'],
-
-  // Most tests are I/O-bound, increase the test timeout globally
-  testTimeout: 20_000,
-
-  // BEGIN https://kulshekhar.github.io/ts-jest/docs/guides/esm-support
-  extensionsToTreatAsEsm: ['.ts'],
-  transform: {
-    '^.+\\.tsx?$': ['ts-jest', { useESM: true }],
-  },
-  moduleNameMapper: {
-    '^(\\.{1,2}/.*)\\.js$': '$1',
-    // END https://kulshekhar.github.io/ts-jest/docs/guides/esm-support
-  },
-
-  // Don't run any compiled versions of the tests, if they exist
-  modulePathIgnorePatterns: ['<rootDir>/dist/'],
-  // Don't report coverage on the test directory
-  coveragePathIgnorePatterns: ['<rootDir>/test/'],
-
-  // Report coverage on all source files, because it won't by default...
-  collectCoverageFrom: ['<rootDir>/src/**/*.{js,cjs,mjs,ts}'],
+import type { Config } from 'jest';
+
+export default async (): Promise<Config> => {
+  // Fix some bad package.json files that don't play well with ts-jest
+  await Promise.all(
+    [
+      // https://github.com/g-plane/cue/issues/1
+      '@gplane/cue',
+    ].map(async (moduleName) => {
+      const modulePath = path.join('node_modules', moduleName);
+      const packagePath = path.join(modulePath, 'package.json');
+      const packageJson = JSON.parse((await fs.promises.readFile(packagePath)).toString());
+
+      packageJson.main = packageJson.main ?? packageJson.exports['.'].import;
+      delete packageJson.exports;
+
+      await fs.promises.writeFile(packagePath, JSON.stringify(packageJson, undefined, 2));
+    }),
+  );
+
+  return {
+    preset: 'ts-jest',
+    testEnvironment: 'node',
+
+    setupFilesAfterEnv: ['jest-extended/all'],
+
+    // Most tests are I/O-bound, increase the test timeout globally
+    testTimeout: 20_000,
+
+    // BEGIN https://kulshekhar.github.io/ts-jest/docs/guides/esm-support
+    extensionsToTreatAsEsm: ['.ts'],
+    transform: {
+      '^.+\\.tsx?$': ['ts-jest', { useESM: true }],
+    },
+    moduleNameMapper: {
+      '^(\\.{1,2}/.*)\\.js$': '$1',
+      // END https://kulshekhar.github.io/ts-jest/docs/guides/esm-support
+    },
+
+    // Don't run any compiled versions of the tests, if they exist
+    modulePathIgnorePatterns: ['<rootDir>/dist/'],
+    // Don't report coverage on the test directory
+    coveragePathIgnorePatterns: ['<rootDir>/test/'],
+
+    // Report coverage on all source files, because it won't by default...
+    collectCoverageFrom: ['<rootDir>/src/**/*.{js,cjs,mjs,ts}'],
+  };
 };
-
-export default jestConfig;