fix: babel-config + adds test

src/__helpers__/fakers.ts

@@ -1,4 +1,4 @@
-import { TsJestGlobalOptions } from '../types';
+import { TsJestGlobalOptions, BabelConfig } from '../types';
 import { resolve } from 'path';
 
 export function filePath(relPath: string): string {
@@ -29,7 +29,7 @@ describe('hello', function () {
 export function htmlSource() {
  return `
 <div>
- <span>some text with \`backtilt\`</span>
+ <span>some text with \`backtick\`</span>
 </div>
 `;
 }
@@ -71,3 +71,11 @@ export function jestConfig<T extends jest.ProjectConfig>(
  }
  return res;
 }
+
+export function babelConfig<T extends BabelConfig>(options?: BabelConfig): T {
+ return {
+ ...options,
+ presets: [...(options && options.presets)],
+ plugins: [...(options && options.plugins)],
+ } as any;
+}

src/utils/babel-config.spec.ts

@@ -0,0 +1,53 @@
+import * as fakers from '../__helpers__/fakers';
+import * as babelCfg from './babel-config';
+import { BabelConfig } from '../types';
+
+describe('extend', () => {
+ let base!: BabelConfig;
+
+ beforeEach(() => {
+ base = fakers.babelConfig({
+ presets: ['preset-1'],
+ plugins: ['plugin-1'],
+ minified: true,
+ });
+ });
+
+ it('should be a copy', () => {
+ const extended = babelCfg.extend(base);
+ expect(extended).toEqual(base);
+ expect(extended).not.toBe(base);
+ expect(extended.presets).not.toBe(base.presets);
+ expect(extended.plugins).not.toBe(base.plugins);
+ });
+
+ it('should extend correctly', () => {
+ const extension: BabelConfig = {
+ minified: false,
+ envName: 'test',
+ plugins: ['plugin-2'],
+ presets: ['preset-2'],
+ };
+ const extended = babelCfg.extend(base, extension);
+ expect(extended).not.toBe(base);
+ expect(extended).not.toBe(extension);
+ expect(extended.presets).not.toBe(base.presets);
+ expect(extended.presets).not.toBe(extension.presets);
+ expect(extended.plugins).not.toBe(base.plugins);
+ expect(extended.plugins).not.toBe(extension.plugins);
+ expect(extended).toMatchInlineSnapshot(`
+Object {
+ "envName": "test",
+ "minified": false,
+ "plugins": Array [
+ "plugin-1",
+ "plugin-2",
+ ],
+ "presets": Array [
+ "preset-1",
+ "preset-2",
+ ],
+}
+`);
+ });
+});

src/utils/babel-config.ts

@@ -31,10 +31,13 @@ export function extend(
  // tslint:disable-next-line:trailing-comma
  ...others: BabelConfig[]
 ): BabelConfig {
- const res = Object.assign(base, extend, ...others, {
+ const res = {
+ ...base,
+ ...extend,
+ ...others,
  presets: base.presets ? base.presets.slice() : [],
- plugins: extend.plugins ? extend.plugins.slice() : [],
- });
+ plugins: base.plugins ? base.plugins.slice() : [],
+ };
  others.unshift(extend);
  others.forEach(other => {
  if (other.presets) {