docs/middleware/categories-for-support.js

import path from 'path'

import { defaultCacheControl } from './cache-control.js'

const renderOpts = { textOnly: true }

// This middleware exposes a list of all categories and child articles at /categories.json.
// GitHub Support uses this for internal ZenDesk search functionality.
export default async function categoriesForSupport(req, res) {
  const englishSiteTree = req.context.siteTree.en
  const allCategories = []

  for (const productPage of Object.values(englishSiteTree['free-pro-team@latest'].childPages)) {
    if (productPage.page.relativePath.startsWith('early-access')) continue
    if (!productPage.childPages || !productPage.childPages.length) continue
    await Promise.all(
      productPage.childPages.map(async (categoryPage) => {
        // We can't get the rendered titles from middleware/render-tree-titles
        // here because that middleware only runs on the current version, and this
        // middleware processes all versions.
        const name = categoryPage.page.title.includes('{')
          ? await categoryPage.page.renderProp('title', req.context, renderOpts)
          : categoryPage.page.title

        allCategories.push({
          name,
          published_articles: await findArticlesPerCategory(categoryPage, [], req.context),
        })
      })
    )
  }

  // Cache somewhat aggressively but note that it will be soft-purged
  // in every prod deployment.
  defaultCacheControl(res)

  return res.json(allCategories)
}

async function findArticlesPerCategory(currentPage, articlesArray, context) {
  if (currentPage.page.documentType === 'article') {
    const title = currentPage.page.title.includes('{')
      ? await currentPage.page.renderProp('title', context, renderOpts)
      : currentPage.page.title

    articlesArray.push({
      title,
      slug: path.basename(currentPage.href),
    })
  }

  if (!currentPage.childPages) return articlesArray

  // Run recursively to find any articles deeper in the tree.
  await Promise.all(
    currentPage.childPages.map(async (childPage) => {
      await findArticlesPerCategory(childPage, articlesArray, context)
    })
  )

  return articlesArray
}