feat: add option to specify beforeX and afterX hooks

closes #2

README.md

@@ -85,6 +85,16 @@ The fixtures directory should contain subdirectories with test files. Every test
 
 You can use `fixtures.skip` and `fixtures.only`, similar to Jest's `describe.skip` and `describe.only`. To skip an individual fixture, you can rename the fixture's directory to `skip.name-of-the-fixture`, and to run a specific fixture only, you can rename the fixture's directory to `only.name-of-the-fixture`.
 
+To use hooks such as `beforeEach`, `afterEach`, `beforeAll` and `afterAll`, you can pass an object with these properties as the third argument:
+
+```js
+fixtures('my plugin', path.join(__dirname, '__fixtures__'), {
+  beforeEach() {
+    // Do some setup here
+  },
+});
+```
+
 By default, it will compare the outputs with the files on the filesystem and you have to manually update the files in case of a mismatch. If you're using Jest, you can use the snapshot feature to automatically update the files with a keypress. ([See below](#integration-with-jest-snapshot)) on how to set it up.
 
 ### Standalone test

index.d.ts

@@ -8,6 +8,20 @@ declare module 'babel-test' {
     options: { filename: string }
   ) => Promise<{ code: string }>;
 
+  type DoneCallback = {
+    (...args: any[]): any;
+    fail(error?: string | { message: string }): any;
+  };
+
+  type LifecycleCallback = (cb: DoneCallback) => any;
+
+  type FixturesOptions = {
+    beforeEach?: LifecycleCallback;
+    afterEach?: LifecycleCallback;
+    beforeAll?: LifecycleCallback;
+    afterAll?: LifecycleCallback;
+  };
+
   type TestRunner<T> = (
     title: string,
     callback: (options: { transform: TransformCallback<T> }) => void
@@ -16,6 +30,7 @@ declare module 'babel-test' {
   type FixturesRunner = (
     title: string,
     directory: string,
+    options?: FixturesOptions,
     callback?: FixturesCallback
   ) => void;
 

src/index.js

@@ -8,14 +8,17 @@ const stripAnsi = require('strip-ansi');
 const escapeRegexp = require('escape-string-regexp');
 const ErrorStackParser = require('error-stack-parser');
 
+const SUPPORTED_RUNNERS_TEXT =
+  'Are you using a supported test runner such as Jest (https://jestjs.io) or Mocha (https://mochajs.org)?';
+
 exports.create = function create(config) {
   // Check if `describe` and `it` globals are available and throw if not
   // This avoids confusion with unsupported test runners and incorect usage
   if (!('describe' in global && 'it' in global)) {
     throw new Error(
       `Couldn't find ${chalk.blue('describe')} and ${chalk.blue(
         'it'
-      )} in the global scope. Are you using a supported test runner such as Jest (https://jestjs.io) or Mocha (https://mochajs.org)?\n`
+      )} in the global scope. ${SUPPORTED_RUNNERS_TEXT}\n`
     );
   }
 
@@ -39,7 +42,32 @@ exports.create = function create(config) {
             )
           );
 
-  const runner = (directory, callback) => () => {
+  const runner = (directory, options, callback) => () => {
+    if (options) {
+      const hooks = [
+        'before',
+        'after',
+        'beforeEach',
+        'afterEach',
+        'beforeAll',
+        'afterAll',
+      ];
+
+      for (const hook of hooks) {
+        if (options[hook] !== undefined) {
+          if (global[hook] !== undefined) {
+            global[hook](options[hook]);
+          } else {
+            throw new Error(
+              `Couldn't find ${chalk.blue(
+                hook
+              )} in the global scope. ${SUPPORTED_RUNNERS_TEXT}\n`
+            );
+          }
+        }
+      }
+    }
+
     fs.readdirSync(directory)
       .filter(f => fs.lstatSync(path.join(directory, f)).isDirectory())
       .forEach(f => {
@@ -160,15 +188,15 @@ exports.create = function create(config) {
 
   // We create a new error here so we can point to user's file in stack trace
   // Otherwise stack traces will point to the library code
-  function fixtures(title, directory, callback = helper(new Error())) {
-    describe(title, runner(directory, callback));
+  function fixtures(title, directory, options, callback = helper(new Error())) {
+    describe(title, runner(directory, options, callback));
   }
 
-  fixtures.skip = (title, directory, callback = helper(new Error())) =>
-    describe.skip(title, runner(directory, callback));
+  fixtures.skip = (title, directory, options, callback = helper(new Error())) =>
+    describe.skip(title, runner(directory, options, callback));
 
-  fixtures.only = (title, directory, callback = helper(new Error())) =>
-    describe.only(title, runner(directory, callback));
+  fixtures.only = (title, directory, options, callback = helper(new Error())) =>
+    describe.only(title, runner(directory, options, callback));
 
   return { test, fixtures };
 };