ci(toolkit): add github comment for missing changelog item (aws#5499)

## Problem
- If a user is using the types feat/fix in the PR title they should also include a changelog item

## Solution
- Notify them if a changelog item isn't present

Author: jpinkney-aws

.github/workflows/lintcommit.js

@@ -11,6 +11,7 @@
 //
 
 const fs = require('fs')
+const { parsePRTitle } = require('./utils')
 // This script intentionally avoids github APIs so that:
 //   1. it is locally-debuggable
 //   2. the CI job is fast ("npm install" is slow)
@@ -68,20 +69,7 @@ void scopes
  * Returns undefined if `title` is valid, else an error message.
  */
 function validateTitle(title) {
-    const parts = title.split(':')
-    const subject = parts.slice(1).join(':').trim()
-
-    if (title.startsWith('Merge')) {
-        return undefined
-    }
-
-    if (parts.length < 2) {
-        return 'missing colon (:) char'
-    }
-
-    const typeScope = parts[0]
-
-    const [type, scope] = typeScope.split(/\(([^)]+)\)$/)
+    const { type, scope, subject } = parsePRTitle(title)
 
     if (/\s+/.test(type)) {
         return `type contains whitespace: "${type}"`

.github/workflows/notify.js

@@ -3,9 +3,14 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-const needsTestFiles =
+const { parsePRTitle, hasPath, dedupComment } = require('./utils')
+
+const testFilesMessage =
     'This pull request modifies files in src/ but no tests were added/updated. Confirm whether tests should be added or ensure the PR description explains why tests are not required.'
 
+const changelogMessage =
+    'This pull request modifies a feature or fixes a bug, but it does not include a changelog entry. All pull requests that introduce new features or bug fixes must have a corresponding changelog item describing the changes.'
+
 /**
  * Remind partner teams that tests are required. We don't need to remind them if:
  *  1. They did not change anything in a src directory
@@ -16,6 +21,7 @@ module.exports = async ({ github, context }) => {
     const owner = context.repo.owner
     const repo = context.repo.repo
     const author = context.payload.pull_request.head.repo.owner.login
+    const pullRequestId = context.payload.pull_request.number
 
     const response = await github.rest.repos.compareCommitsWithBasehead({
         owner,
@@ -25,36 +31,58 @@ module.exports = async ({ github, context }) => {
 
     const filenames = response.data.files.map((file) => file.filename)
 
-    // Check if src directory changed
-    const srcFiles = filenames.filter((file) => file.includes('src/'))
-    if (srcFiles.length === 0) {
-        console.log('Did not find src files in the code changes')
-        return
-    }
+    const shouldAddTestFileMessage = requiresTestFilesMessage(filenames)
+    const shouldAddChangelogMessage = requiresChangelogMessage(filenames, context.payload.pull_request.title)
 
-    // Check if test files were added or modified
-    const testFiles = filenames.filter((file) => file.endsWith('.test.ts'))
-    if (testFiles.length > 0) {
-        console.log('Found test files in the code changes')
+    if (!shouldAddTestFileMessage && !shouldAddChangelogMessage) {
         return
     }
 
     // Check for prior comments on the PR
     const comments = await github.rest.issues.listComments({
         owner,
         repo,
-        issue_number: context.payload.pull_request.number,
+        issue_number: pullRequestId,
     })
 
-    if (comments.data.some((comment) => comment.body.includes(needsTestFiles))) {
-        console.log('Found prior comment indicating tests are needed')
+    if (shouldAddTestFileMessage) {
+        await dedupComment({ github, comments, owner, repo, pullRequestId, message: testFilesMessage })
+    }
+
+    if (shouldAddChangelogMessage) {
+        await dedupComment({ github, comments, owner, repo, pullRequestId, message: changelogMessage })
+    }
+}
+
+/**
+ * Require the changelog message if the scope is fix/feat AND there is no changelog item
+ */
+function requiresChangelogMessage(filenames, title) {
+    try {
+        const { type } = parsePRTitle(title)
+        return !hasPath(filenames, '.changes') && (type === 'fix' || type === 'feat')
+    } catch (e) {
+        console.log(e)
+        return undefined
+    }
+}
+
+/**
+ * Require the test files message if there are changes to source files but aren't any
+ * changes to the test files
+ */
+function requiresTestFilesMessage(filenames) {
+    // Check if src directory changed
+    if (!hasPath(filenames, 'src/')) {
+        console.log('Did not find src files in the code changes')
         return
     }
 
-    await github.rest.issues.createComment({
-        issue_number: context.issue.number,
-        owner,
-        repo,
-        body: needsTestFiles,
-    })
+    // Check if test files were added or modified
+    if (hasPath(filenames, '.test.ts')) {
+        console.log('Found test files in the code changes')
+        return
+    }
+
+    return true
 }

.github/workflows/utils.js

@@ -0,0 +1,55 @@
+/*!
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+function parsePRTitle(title) {
+    const parts = title.split(':')
+    const subject = parts.slice(1).join(':').trim()
+
+    if (title.startsWith('Merge')) {
+        return undefined
+    }
+
+    if (parts.length < 2) {
+        return 'missing colon (:) char'
+    }
+
+    const typeScope = parts[0]
+
+    const [type, scope] = typeScope.split(/\(([^)]+)\)$/)
+    return {
+        type,
+        scope,
+        subject,
+    }
+}
+
+/**
+ * Create a comment on a PR if one does not already exist
+ */
+async function dedupComment({ github, pullRequestId, owner, repo, comments, message }) {
+    if (comments.data.some((comment) => comment.body.includes(message))) {
+        return
+    }
+
+    await github.rest.issues.createComment({
+        issue_number: pullRequestId,
+        owner,
+        repo,
+        body: message,
+    })
+}
+
+/*
+ * Check if path is included in at least one of the filename paths
+ */
+function hasPath(filenames, path) {
+    return filenames.some((file) => file.includes(path))
+}
+
+module.exports = {
+    parsePRTitle,
+    dedupComment,
+    hasPath,
+}