fix: getting events from first push using push event payload

src/action.mjs

@@ -12,6 +12,7 @@ const pullRequestTargetEvent = 'pull_request_target'
 const pullRequestEvents = [pullRequestEvent, pullRequestTargetEvent]
 
 const { GITHUB_EVENT_NAME } = process.env
+const FIRST_COMMIT_SHA = '0000000000000000000000000000000000000000'
 
 const configPath = resolve(process.env.GITHUB_WORKSPACE, getInput('configFile'))
 
@@ -26,6 +27,14 @@ const getPushEventCommits = async () => {
   const octokit = getOctokit(getInput('token'))
   const { owner, repo } = eventContext.issue
   const { before, after } = eventContext.payload
+
+  if (before === FIRST_COMMIT_SHA) {
+    return eventContext.payload.commits.map((commit) => ({
+      message: commit.message,
+      hash: commit.id,
+    }))
+  }
+
   const { data: comparison } = await octokit.rest.repos.compareCommits({
     owner,
     repo,

src/action.test.mjs

@@ -4,11 +4,11 @@ import { git } from '@commitlint/test'
 import { jest, describe, it } from '@jest/globals'
 import * as td from 'testdouble'
 import {
-  updatePushEnvVars,
-  createPushEventPayload,
-  createPullRequestEventPayload,
-  updatePullRequestEnvVars,
   buildResponseCommit,
+  createPullRequestEventPayload,
+  createPushEventPayload,
+  updatePullRequestEnvVars,
+  updatePushEnvVars,
 } from './testUtils.mjs'
 
 const resultsOutputId = 'results'
@@ -451,6 +451,37 @@ describe('Commit Linter action', () => {
     td.verify(console.log('Lint free! 🎉'))
   })
 
+  it('should get commits from event for a first push', async () => {
+    const commit = {
+      id: '0000000000000000000000000000000000000000',
+      message: 'chore: correct message',
+    }
+
+    cwd = await git.bootstrap('fixtures/conventional', process.cwd())
+    await createPushEventPayload(
+      cwd,
+      { commits: [commit] },
+      '0000000000000000000000000000000000000000',
+    )
+    updatePushEnvVars(cwd)
+    td.when(
+      mockCompareCommits({
+        owner: 'wagoid',
+        repo: 'commitlint-github-action',
+        head: 'aaaaa',
+        base: '0000000000000000000000000000000000000000',
+        per_page: 100,
+      }),
+    ).thenResolve({
+      data: { commits: [buildResponseCommit(commit.id, commit.message)] },
+    })
+    td.replace(process, 'cwd', () => cwd)
+    td.replace(console, 'log')
+
+    td.verify(mockCore.setFailed(), { times: 0, ignoreExtraArgs: true })
+    td.verify(mockCompareCommits(), { times: 0 })
+  })
+
   describe.each(['pull_request', 'pull_request_target'])(
     'when there are multiple commits failing in the %s event',
     (eventName) => {