message: core: fix app config tests on windows
diff: */
  import { defaultConfigLoader } from './createApp';
  -import { AppConfig } from '@backstage/config';
  +
  +(process as any).env = { NODE_ENV: 'test' };
  +const anyEnv = process.env as any;
  describe('defaultConfigLoader', () => {
  afterEach(() => {
  - delete process.env.APP_CONFIG;
  + delete anyEnv.APP_CONFIG;
  });
  it('loads static config', async () => {
  - Object.defineProperty(process.env, 'APP_CONFIG', {
  - configurable: true,
  - value: [
  + anyEnv.APP_CONFIG = [
  { data: { my: 'config' }, context: 'a' },
  { data: { my: 'override-config' }, context: 'b' },
  - ] as AppConfig[],
  - });
  + ];
  +
  const configs = await defaultConfigLoader();
  expect(configs).toEqual([
  { data: { my: 'config' }, context: 'a' },
  @@ -38,13 +38,11 @@ describe('defaultConfigLoader', () => {
  });
  it('loads runtime config', async () => {
  - Object.defineProperty(process.env, 'APP_CONFIG', {
  - configurable: true,
  - value: [
  + anyEnv.APP_CONFIG = [
  { data: { my: 'override-config' }, context: 'a' },
  { data: { my: 'config' }, context: 'b' },
  - ] as AppConfig[],
  - });
  + ];
  +
  const configs = await (defaultConfigLoader as any)(
  '{"my":"runtime-config"}',
  );
  @@ -62,20 +60,14 @@ describe('defaultConfigLoader', () => {
  });
  it('fails to load invalid static config', async () => {
  - Object.defineProperty(process.env, 'APP_CONFIG', {
  - configurable: true,
  - value: { my: 'invalid-config' } as any,
  - });
  + anyEnv.APP_CONFIG = { my: 'invalid-config' };
  await expect(defaultConfigLoader()).rejects.toThrow(
  'Static configuration has invalid format',
  );
  });
  it('fails to load bad runtime config', async () => {
  - Object.defineProperty(process.env, 'APP_CONFIG', {
  - configurable: true,
  - value: [{ data: { my: 'config' }, context: 'a' }] as AppConfig[],
  - });
  + anyEnv.APP_CONFIG = [{ data: { my: 'config' }, context: 'a' }];
  await expect((defaultConfigLoader as any)('}')).rejects.toThrow(
  'Failed to load runtime configuration, SyntaxError: Unexpected token } in JSON at position 0',
  