feat: add testing-library expect matchers

package.json

@@ -26,6 +26,7 @@
   "dependencies": {
     "@storybook/expect": "storybook-jest",
     "@storybook/instrumenter": "6.4.0-rc.5",
+    "@testing-library/jest-dom": "^5.16.2",
     "jest-mock": "^27.3.0"
   },
   "devDependencies": {

src/index.ts

@@ -1,10 +1,15 @@
 import { default as expectPatched } from '@storybook/expect';
 import { instrument } from '@storybook/instrumenter';
+import * as matchers from '@testing-library/jest-dom/matchers';
 import * as mock from 'jest-mock';
 
-export const { jest } = instrument({ jest: mock });
+const { jest } = instrument({ jest: mock });
 
-export const expect: typeof expectPatched = instrument(
+const expect: typeof expectPatched = instrument(
   { expect: expectPatched },
-  { intercept: (method, path) => path[0] !== 'expect' }
+  { intercept: (_method, path) => path[0] !== 'expect' }
 ).expect;
+
+expect.extend(matchers);
+
+export { expect, jest };

src/typings.d.ts

@@ -0,0 +1 @@
+declare module '@testing-library/jest-dom/matchers';