Set up GitHub Actions CI workflow for all 4 languages

[thatsjet]

Summary

Create a CI workflow that runs tests for all 4 languages on every PR and push to main.

Prerequisites

• Issue Add test suites for all 4 languages #8 (test suites) must be completed first

Instructions

Create .github/workflows/ci.yml

name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  python:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: ['3.9', '3.12', '3.13']
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: \${{ matrix.python-version }}
      - run: pip install pyyaml pytest
        working-directory: python
      - run: pytest tests/ -v
        working-directory: python

  nodejs:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node-version: ['18', '20', '22']
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: \${{ matrix.node-version }}
      - run: npm install
        working-directory: nodejs
      - run: npm test
        working-directory: nodejs

  golang:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        go-version: ['1.21', '1.22', '1.23']
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-go@v5
        with:
          go-version: \${{ matrix.go-version }}
      - run: go vet ./...
        working-directory: golang
      - run: go test -v ./...
        working-directory: golang

  java:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        java-version: ['11', '17', '21']
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-java@v4
        with:
          java-version: \${{ matrix.java-version }}
          distribution: 'temurin'
      - run: mvn test -B
        working-directory: java

Also create .gitignore in repo root

# Python
python/__pycache__/
python/*.egg-info/
python/.venv/
python/dist/
python/build/

# Node.js
nodejs/node_modules/

# Go
golang/vendor/

# Java
java/target/

# IDE
.idea/
.vscode/
*.iml

# OS
.DS_Store
Thumbs.db

Verification

• Push a PR and verify all 4 language jobs run and pass
• Matrix produces 3 versions × 4 languages = 12 jobs
• .gitignore prevents build artifacts from being committed