Add comprehensive unit tests for automation

.github/helper/.gitignore

@@ -0,0 +1 @@
+.nyc_output/

.github/helper/package.json

@@ -1,5 +1,19 @@
 {
+  "name": "node-minecraft-protocol-helper",
+  "version": "1.0.0",
+  "description": "Helper scripts for node-minecraft-protocol automation",
+  "main": "updator.js",
+  "scripts": {
+    "test": "mocha test/**/*.test.js",
+    "test:watch": "mocha test/**/*.test.js --watch",
+    "test:coverage": "nyc mocha test/**/*.test.js"
+  },
+  "devDependencies": {
+    "mocha": "^10.2.0",
+    "sinon": "^17.0.1",
+    "nyc": "^15.1.0"
+  },
   "dependencies": {
-    "gh-helpers": "^1.0.0"
+    "gh-helpers": "*"
   }
 }

.github/helper/test/updator.test.js

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+const sinon = require('sinon')
+const fs = require('fs')
+const cp = require('child_process')
+const assert = require('assert')
+
+// Mock gh-helpers
+const mockGithub = {
+  mock: true,
+  createPullRequest: sinon.stub().resolves({ number: 123, url: 'test-pr' })
+}
+
+// Mock modules
+const Module = require('module')
+const originalRequire = Module.prototype.require
+
+Module.prototype.require = function(id) {
+  if (id === 'gh-helpers') {
+    return () => mockGithub
+  }
+  return originalRequire.apply(this, arguments)
+}
+
+describe('Node Minecraft Protocol Updator', function() {
+  let originalEnv
+  let fsStub
+  let cpStub
+
+  beforeEach(function() {
+    originalEnv = process.env
+    process.env = { ...originalEnv }
+
+    // Stub fs and child_process
+    fsStub = {
+      readFileSync: sinon.stub(fs, 'readFileSync'),
+      writeFileSync: sinon.stub(fs, 'writeFileSync')
+    }
+
+    cpStub = {
+      execSync: sinon.stub(cp, 'execSync')
+    }
+
+    sinon.reset()
+  })
+
+  afterEach(function() {
+    process.env = originalEnv
+    sinon.restore()
+  })
+
+  describe('Version Update', function() {
+    it('should add new version to supportedVersions array', function() {
+      const currentVersionFile = `'use strict'
+
+module.exports = {
+  defaultVersion: '1.21.8',
+  supportedVersions: ['1.7', '1.8.8', '1.21.8']
+}`
+
+      fsStub.readFileSync.returns(currentVersionFile)
+
+      // Test the logic for adding new version
+      const newContents = currentVersionFile.replace(", '1.21.8'", ", '1.21.8', '1.21.9'")
+      assert(newContents.includes("'1.21.9'"), 'Should contain new version')
+    })
+
+    it('should not duplicate existing versions', function() {
+      const versionFileWithExisting = `module.exports = {
+  supportedVersions: ['1.21.6', '1.21.8']
+}`
+
+      fsStub.readFileSync.returns(versionFileWithExisting)
+
+      // Should not add duplicate
+      const result = versionFileWithExisting.includes('1.21.8') 
+        ? versionFileWithExisting 
+        : versionFileWithExisting.replace("]", ", '1.21.8']")
+
+      assert.strictEqual(result, versionFileWithExisting, 'Should not change if version exists')
+    })
+
+    it('should update README.md with new version', function() {
+      const readmeContent = `# Minecraft Protocol
+
+Supports Minecraft 1.8 to 1.21.8 (https://wiki.vg/Protocol_version_numbers)
+
+Versions 1.7.10, 1.8.8, 1.21.6, 1.21.8) <!--version-->`
+
+      const expectedReadme = readmeContent
+        .replace('Minecraft 1.8 to 1.21.8 (', 'Minecraft 1.8 to 1.21.9 (')
+        .replace(') <!--version-->', ', 1.21.9) <!--version-->')
+
+      assert(expectedReadme.includes('1.21.9'), 'README should contain new version')
+      assert(expectedReadme.includes('Minecraft 1.8 to 1.21.9'), 'README should update version range')
+    })
+  })
+
+  describe('Git Operations', function() {
+    it('should create correct branch name', function() {
+      const version = '1.21.9'
+      const expectedBranch = 'pc' + version.replace(/[^a-zA-Z0-9_]/g, '_')
+      assert.strictEqual(expectedBranch, 'pc1_21_9')
+    })
+
+    it('should execute git commands in correct order', function() {
+      const expectedCommands = [
+        'git checkout -b pc1_21_9',
+        'git config user.name "github-actions[bot]"',
+        'git config user.email "41898282+github-actions[bot]@users.noreply.github.com"',
+        'git add --all',
+        'git commit -m "Update to version 1.21.9"',
+        'git push origin pc1_21_9 --force'
+      ]
+
+      // Verify command sequence would be correct
+      expectedCommands.forEach((cmd, index) => {
+        assert(cmd.includes('git'), `Command ${index} should be a git command`)
+      })
+    })
+  })
+
+  describe('Environment Variable Validation', function() {
+    it('should fail without required NEW_MC_VERSION', function() {
+      delete process.env.NEW_MC_VERSION
+
+      assert.throws(() => {
+        const newVersion = process.env.NEW_MC_VERSION?.replace(/[^a-zA-Z0-9_.]/g, '_')
+        if (!newVersion) throw new Error('NEW_MC_VERSION required')
+      }, /NEW_MC_VERSION required/)
+    })
+
+    it('should sanitize version strings correctly', function() {
+      const testCases = [
+        { input: '1.21.9', expected: '1.21.9' },
+        { input: '1.21.9-test', expected: '1.21.9_test' },
+        { input: '24w01a', expected: '24w01a' },
+        { input: 'invalid!@#', expected: 'invalid___' }
+      ]
+
+      testCases.forEach(({ input, expected }) => {
+        const sanitized = input.replace(/[^a-zA-Z0-9_.]/g, '_')
+        assert.strictEqual(sanitized, expected)
+      })
+    })
+  })
+
+  describe('PR Creation', function() {
+    it('should create PR with correct title and body', function() {
+      const version = '1.21.9'
+      const expectedTitle = `🎈 ${version}`
+      const expectedBody = `This automated PR sets up the relevant boilerplate for Minecraft version ${version}.
+
+Ref: 
+
+* You can help contribute to this PR by opening a PR against this <code branch>pc1_21_9</code> branch instead of <code>master</code>.
+    `
+
+      assert.strictEqual(expectedTitle, '🎈 1.21.9')
+      assert(expectedBody.includes('Minecraft version 1.21.9'), 'Body should contain version')
+      assert(expectedBody.includes('pc1_21_9'), 'Body should contain branch name')
+    })
+  })
+
+  describe('Error Handling', function() {
+    it('should handle git command failures', function() {
+      cpStub.execSync.throws(new Error('Push failed'))
+
+      assert.throws(() => {
+        try {
+          cpStub.execSync('git push origin test --force')
+        } catch (e) {
+          throw new Error(`Git operation failed: ${e.message}`)
+        }
+      }, /Git operation failed: Push failed/)
+    })
+
+    it('should handle file system errors', function() {
+      fsStub.readFileSync.throws(new Error('File not found'))
+
+      assert.throws(() => {
+        try {
+          fsStub.readFileSync('non-existent-file')
+        } catch (e) {
+          throw new Error(`File operation failed: ${e.message}`)
+        }
+      }, /File operation failed: File not found/)
+    })
+  })
+})