Useful Github Actions

Setting GitHub actions is a headache, and it takes time to run correctly. I’ll share what actions I daily use.

How to add github actions?

Add github actions on your branch

.github/workflows/xxxx.yml

Trigger github action by leaving a comment on PR

Scenario 1: share new build to someone

You can define commands to run action

For example, If you want to share something to test, use this action.

share is command
test is userId

And you can leave a comment using github.issues.createComment

This action is very useful. You can integrate third-party services like Slack, WhatsApp, or Linear. Listening share command and trigger action whatever you want to share it.

name: Comment Action
on:
  issue_comment:
    types: [created]
jobs:
  comment_job:
    runs-on: ubuntu-latest
    steps:
      - name: Check Comment Type
        id: check_comment
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const comment = context.payload.comment.body.trim();
            console.log(`Received comment: ${comment}`);

            const issueOrPrNumber = context.payload.issue?.number || context.payload.pull_request?.number;
            if (!issueOrPrNumber) {
              throw new Error("Could not determine issue or PR number.");
            }

            let action = '';
            if (comment.startsWith('share')) {
              action = 'share';
            }

            core.setOutput('action', action);
            core.setOutput('comment', comment);
            core.setOutput('issue_or_pr_number', issueOrPrNumber);
      
      - name: Handle Share Command
        if: steps.check_comment.outputs.action == 'share'
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const comment = '${{ steps.check_comment.outputs.comment }}';
            const issueOrPrNumber = '${{ steps.check_comment.outputs.issue_or_pr_number }}';

            if (!issueOrPrNumber) {
              throw new Error("Could not determine the issue or PR number.");
            }

            const splitComment = comment.split(' ');
            if (splitComment.length < 2) {
              throw new Error("Invalid 'share' command format. Expected: 'share <id>'");
            }

            const recipientId = splitComment[1]; // Extract ID after "share"
            const commentBody = `Sharing this with: ${recipientId}`;

            console.log(`Adding a share comment for ID: ${recipientId}`);
            await github.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issueOrPrNumber,
              body: commentBody
            });

scenario 2: rebuild when the build failed

There are 2 yml files in workflows

When you get a build failed message, you can rebuild it by leaving a comment.

comment_action.yml

Get PR Number using github.pulls.get
Pass issue_or_pr_number as Inputs to build.yml

name: Comment Action
on:
  issue_comment:
    types: [created]

jobs:
  comment_job:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: GitHub CLI Login
        run: |
          gh auth login --with-token <<< "${{ secrets.GITHUB_TOKEN }}"
      - name: Check Comment Type
        id: check_comment
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const comment = context.payload.comment.body.trim();
            console.log(`Received comment: ${comment}`);
        
            const issueOrPrNumber = context.payload.issue?.number || context.payload.pull_request?.number;
            const isPR = Boolean(context.payload.issue.pull_request);

            if (!isPR) {
              throw new Error("This comment is not associated with a pull request.");
            }

            const { data: pullRequest } = await github.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: issueOrPrNumber,
            });

            const sourceBranch = pullRequest.head.ref;
            const targetBranch = pullRequest.base.ref;

            console.log(`Source branch: ${sourceBranch}`);
            console.log(`Target branch: ${targetBranch}`);
            if (!issueOrPrNumber) {
              throw new Error("Could not determine issue or PR number.");
            }

            let action = '';
            if (comment === 'rebuild') {
              action = 'rebuild';
            }

            core.setOutput('action', action);
            core.setOutput('comment', comment);
            core.setOutput('issue_or_pr_number', issueOrPrNumber);
            core.setOutput('source_branch', sourceBranch);
            core.setOutput('target_branch', targetBranch);

      - name: Rebuild
        run: |
          echo "🟢 Issue or PR Number: ${{ steps.check_comment.outputs.issue_or_pr_number }}"
          gh workflow run rebuild.yml --ref ${{ steps.check_comment.outputs.target_branch }} -f issue_or_pr_number=${{ steps.check_comment.outputs.issue_or_pr_number }}
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

build.yml

define workflow_dispatch and inputs

name: build

on:
  workflow_dispatch:
    inputs:
      issue_or_pr_number:
        description: "The issue or PR number to comment on"
        required: true

jobs:
  reusable_job:
    runs-on: ubuntu-latest
    steps:
      - name: Build
        run: echo "Running workflow"
      - name: Rebuild triggered
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const issueOrPrNumber = ${{ github.event.inputs.issue_or_pr_number }};
            console.log(`🟢 Input issue_or_pr_number: ${issueOrPrNumber}`);
            if (!issueOrPrNumber) {
              throw new Error("Could not determine the issue or PR number.");
            }
            const commentBody = `Rebuild triggered`;
            await github.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issueOrPrNumber,
              body: commentBody
            });

scenario 3: read latest build success message and share it to someone

build.yml

Just leave a comment on PR

name: Build

on:
  pull_request:
    branches:
      - master
    types:
      - opened
      - synchronize
      - reopened
      - edited
jobs:
  run_on_pr:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Code
        uses: actions/checkout@v4
      - name: Comment on PR
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const issueOrPrNumber = context.payload.pull_request.number;
            console.log(issueOrPrNumber);

            await github.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issueOrPrNumber,
              body: "iOS v12.0(1022)"
            });

            await github.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issueOrPrNumber,
              body: "Android 15.0(1022)"
            });

comment_action.yml

await github.issues.listComments
- default page_num is 30. If your PR have many comments, I suggest you set page_num 100

name: Comment Action
on:
  issue_comment:
    types: [created]

jobs:
  comment_job:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: GitHub CLI Login
        run: |
          gh auth login --with-token <<< "${{ secrets.GITHUB_TOKEN }}"
      - name: Check Comment Type
        id: check_comment
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const comment = context.payload.comment.body.trim();
            console.log(`Received comment: ${comment}`);
        
            const issueOrPrNumber = context.payload.issue?.number || context.payload.pull_request?.number;
            const isPR = Boolean(context.payload.issue.pull_request);

            if (!isPR) {
              throw new Error("This comment is not associated with a pull request.");
            }

            const { data: pullRequest } = await github.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: issueOrPrNumber
            });

            const sourceBranch = pullRequest.head.ref;
            const targetBranch = pullRequest.base.ref;

            console.log(`Source branch: ${sourceBranch}`);
            console.log(`Target branch: ${targetBranch}`);

            core.setOutput('source_branch', sourceBranch);
            core.setOutput('target_branch', targetBranch);
            if (!issueOrPrNumber) {
              throw new Error("Could not determine issue or PR number.");
            }

            let action = '';
            if (comment.startsWith('share')) {
              action = 'share';
            }

            core.setOutput('action', action);
            core.setOutput('comment', comment);
            core.setOutput('issue_or_pr_number', issueOrPrNumber);

      - name: Get Latest Build Comments
        if: steps.check_comment.outputs.action == 'share'
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const issueNumber = ${{ steps.check_comment.outputs.issue_or_pr_number }};
            const comment = '${{ steps.check_comment.outputs.comment }}';

            if (!issueNumber) {
              throw new Error("Could not determine the issue or PR number.");
            }

            const splitComment = comment.split(' ');
            if (splitComment.length < 2) {
              throw new Error("Invalid 'share' command format. Expected: 'share <id>'");
            }

            const recipientId = splitComment[1]; // Extract ID after "share"
            
            // Fetch all comments on the PR
            const comments = await github.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issueNumber,
              per_page: 100,
            });

            console.log("✅ All Comments")
            comments.data.forEach(comment => console.log(`- ${comment.body}`));


            // Filter and find the most recent iOS-related comment
            const latestIOS = comments.data
              .filter(comment => comment.body.startsWith('iOS'))
              .sort((a, b) => new Date(b.updated_at) - new Date(a.updated_at))[0];

            // Filter and find the most recent Android-related comment
            const latestAndroid = comments.data
              .filter(comment => comment.body.startsWith('Android'))
              .sort((a, b) => new Date(b.updated_at) - new Date(a.updated_at))[0];

            if (latestIOS) {
              console.log(`Latest iOS Comment: ${latestIOS.body}`);
              core.setOutput('latest_ios_comment', latestIOS.body);
            } else {
              console.log('No iOS-related comments found.');
            }

            if (latestAndroid) {
              console.log(`Latest Android Comment: ${latestAndroid.body}`);
              core.setOutput('latest_android_comment', latestAndroid.body);
            } else {
              console.log('No Android-related comments found.');
            }
            const commentBody = `Sharing this with: ${recipientId}\nReady for Testing\n${latestIOS.body}\n${latestAndroid.body}`;
            await github.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issueNumber,
              body: commentBody
            });

Shawn