feat: handle merge_group event - get squashed commit (#806)

* feat: handle merge_group event - get squashed commit

* test: merge_group event

* chore: temporarily change docker image

* Revert "chore: temporarily change docker image"

This reverts commit 39350effdcf4bfff6d24ed897f5d9ae5c6dbb4c2.

* docs: update merge_group event support

src/action.mjs

@@ -7,6 +7,7 @@ import { format } from '@commitlint/format'
 import load from '@commitlint/load'
 import generateOutputs from './generateOutputs.mjs'
 
+const mergeGroupEvent = 'merge_group'
 const pullRequestEvent = 'pull_request'
 const pullRequestTargetEvent = 'pull_request_target'
 const pullRequestEvents = [pullRequestEvent, pullRequestTargetEvent]
@@ -65,7 +66,21 @@ const getPullRequestEventCommits = async () => {
   }))
 }
 
+const getMergeGroupEventCommits = async () => {
+  const { merge_group: mergeGroup } = eventContext.payload
+
+  return [
+    {
+      message: mergeGroup.head_commit.message,
+      hash: mergeGroup.head_sha,
+    },
+  ]
+}
+
 const getEventCommits = async () => {
+  if (GITHUB_EVENT_NAME === mergeGroupEvent) {
+    return getMergeGroupEventCommits()
+  }
   if (pullRequestEvents.includes(GITHUB_EVENT_NAME)) {
     return getPullRequestEventCommits()
   }

src/action.test.mjs

@@ -5,8 +5,10 @@ import { jest, describe, it } from '@jest/globals'
 import * as td from 'testdouble'
 import {
   buildResponseCommit,
+  createMergeGroupEventPayload,
   createPullRequestEventPayload,
   createPushEventPayload,
+  updateMergeGroupEnvVars,
   updatePullRequestEnvVars,
   updatePushEnvVars,
 } from './testUtils.mjs'
@@ -952,4 +954,56 @@ describe('Commit Linter action', () => {
       td.verify(mockCore.setFailed(contains(incorrectCommit.message)))
     })
   })
+
+  describe('when handling merge_group event', () => {
+    beforeEach(async () => {
+      cwd = await git.bootstrap('fixtures/conventional', process.cwd())
+      td.when(mockCore.getInput('configFile')).thenReturn(
+        './commitlint.config.mjs',
+      )
+
+      td.replace(process, 'cwd', () => cwd)
+      td.replace(console, 'log')
+    })
+
+    it('should lint the squashed commit message successfully', async () => {
+      const mergeGroupData = {
+        head_sha: 'merge-group-head-sha',
+        head_commit: {
+          id: 'merge-group-head-sha',
+          message: 'feat: add new feature\n\nThis is a detailed description.',
+          tree_id: 'tree-sha',
+        },
+      }
+
+      await createMergeGroupEventPayload(cwd, mergeGroupData)
+      updateMergeGroupEnvVars(cwd)
+
+      await runAction()
+
+      td.verify(mockCore.setFailed(), { times: 0, ignoreExtraArgs: true })
+      td.verify(console.log('Lint free! 🎉'))
+    })
+
+    it('should fail if the squashed commit message has linting errors', async () => {
+      const mergeGroupData = {
+        head_sha: 'merge-group-head-sha',
+        head_commit: {
+          id: 'merge-group-head-sha',
+          message: 'bad commit message',
+          tree_id: 'tree-sha',
+        },
+      }
+
+      await createMergeGroupEventPayload(cwd, mergeGroupData)
+      updateMergeGroupEnvVars(cwd)
+
+      await runAction()
+
+      td.verify(
+        mockCore.setFailed(contains('You have commit messages with errors')),
+      )
+      td.verify(mockCore.setFailed(contains('bad commit message')))
+    })
+  })
 })

src/testUtils.mjs

@@ -77,3 +77,32 @@ export const buildResponseCommit = (sha, message) => ({
     message,
   },
 })
+
+export const createMergeGroupEventPayload = async (cwd, mergeGroupData) => {
+  const payload = {
+    action: 'checks_requested',
+    merge_group: mergeGroupData,
+    repository: {
+      owner: {
+        login: 'wagoid',
+      },
+      name: 'commitlint-github-action',
+    },
+  }
+
+  const eventPath = path.join(cwd, 'mergeGroupEventPayload.json')
+
+  updateEnvVars({
+    GITHUB_EVENT_PATH: eventPath,
+    GITHUB_EVENT_NAME: 'merge_group',
+    GITHUB_REPOSITORY: 'wagoid/commitlint-github-action',
+  })
+  await writeFile(eventPath, JSON.stringify(payload), 'utf8')
+}
+
+export const updateMergeGroupEnvVars = (cwd) => {
+  updateEnvVars({
+    GITHUB_WORKSPACE: cwd,
+    GITHUB_EVENT_NAME: 'merge_group',
+  })
+}