catalog-ui/src/jest/test-config.helper.ts

import { TestBed } from '@angular/core/testing'

type CompilerOptions = Partial<{
  providers: any[]
  useJit: boolean
  preserveWhitespaces: boolean
}>
export type ConfigureFn = (testBed: typeof TestBed) => void

export const configureTests = (configure: ConfigureFn, compilerOptions: CompilerOptions = {}) => {
  const compilerConfig: CompilerOptions = {
    preserveWhitespaces: false,
    ...compilerOptions,
  };

  const configuredTestBed = TestBed.configureCompiler(compilerConfig);

  configure(configuredTestBed);

  return configuredTestBed.compileComponents().then(() => configuredTestBed)
};