Port whats-new-changelog.js to TypeScript (#51199)

Author: peterbe

src/changelogs/lib/changelog.js renamed to src/changelogs/lib/changelog.ts

@@ -4,26 +4,32 @@ import path from 'path'
 
 import Parser from 'rss-parser'
 
+import type { ChangelogItem } from '@/types'
+
 const CHANGELOG_CACHE_FILE_PATH = process.env.CHANGELOG_CACHE_FILE_PATH
 // This is useful to set when doing things like sync search.
 const CHANGELOG_DISABLED = Boolean(JSON.parse(process.env.CHANGELOG_DISABLED || 'false'))
 
-async function getRssFeed(url) {
+async function getRssFeed(url: string) {
   const parser = new Parser({ timeout: 5000 })
   const feedUrl = `${url}/feed`
   let feed
 
   try {
     feed = await parser.parseURL(feedUrl)
   } catch (err) {
-    console.error(`cannot get ${feedUrl}: ${err.message}`)
+    console.error(`cannot get ${feedUrl}: ${err instanceof Error ? err.message : err}`)
     return
   }
 
   return feed
 }
 
-export async function getChangelogItems(prefix, feedUrl, ignoreCache = false) {
+export async function getChangelogItems(
+  prefix: string | undefined,
+  feedUrl: string,
+  ignoreCache = false,
+): Promise<ChangelogItem[] | undefined> {
   if (CHANGELOG_DISABLED) {
     if (process.env.NODE_ENV === 'development') {
       console.warn(`Downloading changelog (${feedUrl}) items is disabled.`)
@@ -44,14 +50,15 @@ export async function getChangelogItems(prefix, feedUrl, ignoreCache = false) {
   }
 
   // only show the first 3 posts
-  const changelog = feed.items.slice(0, 3).map((item) => {
+  const changelog: ChangelogItem[] = feed.items.slice(0, 3).map((item) => {
+    const rawTitle = item.title as string
     // remove the prefix if it exists (Ex: 'GitHub Actions: '), where the colon and expected whitespace should be hardcoded.
-    const title = prefix ? item.title.replace(new RegExp(`^${prefix}`), '') : item.title
+    const title = prefix ? rawTitle.replace(new RegExp(`^${prefix}`), '') : rawTitle
     return {
       // capitalize the first letter of the title
       title: title.trim().charAt(0).toUpperCase() + title.slice(1),
-      date: item.isoDate,
-      href: item.link,
+      date: item.isoDate as string,
+      href: item.link as string,
     }
   })
 
@@ -65,13 +72,13 @@ export async function getChangelogItems(prefix, feedUrl, ignoreCache = false) {
 
 const globalCache = new Map()
 
-function getChangelogCacheKey(prefix, feedUrl) {
+function getChangelogCacheKey(prefix: string | undefined, feedUrl: string) {
   // Return a string that is only letters so it's safe to use this
   // for the filename when caching to disk.
   return `${prefix || ''}${feedUrl}`.replace(/[^a-z]+/gi, '')
 }
 
-function getDiskCachePath(prefix, feedUrl) {
+function getDiskCachePath(prefix: string | undefined, feedUrl: string) {
   // When in local development or in tests, use disk caching
   if (process.env.NODE_ENV === 'test' || process.env.NODE_ENV === 'development') {
     if (CHANGELOG_CACHE_FILE_PATH) {
@@ -84,7 +91,7 @@ function getDiskCachePath(prefix, feedUrl) {
   }
 }
 
-function getChangelogItemsFromCache(prefix, feedUrl) {
+function getChangelogItemsFromCache(prefix: string | undefined, feedUrl: string) {
   const cacheKey = getChangelogCacheKey(prefix, feedUrl)
 
   if (globalCache.get(cacheKey)) {
@@ -103,7 +110,7 @@ function getChangelogItemsFromCache(prefix, feedUrl) {
       return payload
     } catch (err) {
       // If it wasn't on disk, that's fine.
-      if (err.code === 'ENOENT') return
+      if (err instanceof Error && 'code' in err && err.code === 'ENOENT') return
       // The JSON.parse() most likely failed. Ignore the error
       // but delete the file so it won't be attempted again.
       if (err instanceof SyntaxError) {
@@ -115,7 +122,11 @@ function getChangelogItemsFromCache(prefix, feedUrl) {
   }
 }
 
-function setChangelogItemsCache(prefix, feedUrl, payload) {
+function setChangelogItemsCache(
+  prefix: string | undefined,
+  feedUrl: string,
+  payload: ChangelogItem[],
+) {
   const cacheKey = getChangelogCacheKey(prefix, feedUrl)
   globalCache.set(cacheKey, payload)
 

src/changelogs/tests/get-rss-feeds.js renamed to src/changelogs/tests/get-rss-feeds.ts

@@ -4,10 +4,11 @@ import path from 'path'
 import nock from 'nock'
 import { afterAll, beforeAll, describe, expect, test } from 'vitest'
 
-import { getChangelogItems } from '#src/changelogs/lib/changelog.js'
+import { getChangelogItems } from '@/changelogs/lib/changelog'
+import type { ChangelogItem } from '@/types'
 
 describe('getChangelogItems module', () => {
-  let changelog
+  let changelog: ChangelogItem[] | undefined
 
   beforeAll(async () => {
     const rssFeedContent = await fs.readFile(
@@ -35,7 +36,7 @@ describe('getChangelogItems module', () => {
   afterAll(() => nock.cleanAll())
 
   test('changelog contains 3 items', async () => {
-    expect(changelog.length).toEqual(3)
+    expect(changelog && changelog.length).toEqual(3)
   })
 
   test('each changelog item has expected title, date, and href', async () => {
@@ -57,6 +58,7 @@ describe('getChangelogItems module', () => {
       },
     ]
 
+    if (!changelog) throw new Error('changelog is undefined')
     for (let i = 0; i < 3; i++) {
       const changeLogEntry = changelog[i]
       const expectedEntry = expectedChangelogValues[i]

src/frame/middleware/context/whats-new-changelog.js renamed to src/frame/middleware/context/whats-new-changelog.ts

@@ -1,7 +1,15 @@
-import { getChangelogItems } from '#src/changelogs/lib/changelog.js'
-import getApplicableVersions from '#src/versions/lib/get-applicable-versions.js'
+import type { Response, NextFunction } from 'express'
 
-export default async function whatsNewChangelog(req, res, next) {
+import { getChangelogItems } from '@/changelogs/lib/changelog.js'
+import getApplicableVersions from '@/versions/lib/get-applicable-versions.js'
+import type { ExtendedRequest } from '@/types'
+
+export default async function whatsNewChangelog(
+  req: ExtendedRequest,
+  res: Response,
+  next: NextFunction,
+) {
+  if (!req.context) throw new Error('request not contextualized')
   if (!req.context.page) return next()
   if (!req.context.page.changelog) return next()
   const label = req.context.page.changelog.label.split(/\s+/g).join('')
@@ -16,7 +24,7 @@ export default async function whatsNewChangelog(req, res, next) {
     }
   }
 
-  const labelUrls = {
+  const labelUrls: Record<string, string> = {
     education: 'https://github.blog/category/community/education',
     enterprise: 'https://github.blog/category/enterprise/',
   }

src/frame/middleware/index.ts

@@ -38,7 +38,7 @@ import categoriesForSupport from './categories-for-support'
 import triggerError from '@/observability/middleware/trigger-error'
 import secretScanning from '@/secret-scanning/middleware/secret-scanning'
 import ghesReleaseNotes from '@/release-notes/middleware/ghes-release-notes'
-import whatsNewChangelog from './context/whats-new-changelog.js'
+import whatsNewChangelog from './context/whats-new-changelog'
 import layout from './context/layout.js'
 import currentProductTree from './context/current-product-tree.js'
 import genericToc from './context/generic-toc.js'

src/types.ts

@@ -74,6 +74,8 @@ export type Context = {
   languages?: Languages
   redirectNotFound?: string
   earlyAccessPageLinks?: string
+  changelogUrl?: string
+  whatsNewChangelog?: ChangelogItem[]
   secretScanningData?: SecretScanningData[]
   ghesReleases?: GHESRelease[]
   ghesReleaseNotes?: GHESReleasePatch[]
@@ -123,6 +125,12 @@ export type ReleaseNotes = {
   }
 }
 
+export type ChangelogItem = {
+  title: string
+  date: string
+  href: string
+}
+
 export type SecretScanningData = {
   provider: string
   supportedSecret: string
@@ -176,6 +184,13 @@ export type Page = {
   markdown: string
   versions: FrontmatterVersions
   applicableVersions: string[]
+  changelog?: ChangeLog
+}
+
+type ChangeLog = {
+  label: string
+  prefix?: string
+  versions?: FrontmatterVersions
 }
 
 export type Tree = {