Throw error on mismatched versioning (github#16191)

* throw an error if a page is available in a version that its parent product is not available in

* add tests

* fix one Insights content file versioned for FPT when Insights is only available in GHES currently

content/insights/installing-and-configuring-github-insights/updating-github-insights.md

@@ -6,7 +6,6 @@ redirect_from:
   - /github/installing-and-configuring-github-insights/updating-github-insights
 permissions: 'People with read permissions to the `github/insights-releases` repository and administrative access to the application server can update {% data variables.product.prodname_insights %}.'
 versions:
-  free-pro-team: '*'
   enterprise-server: '*'
 ---
 

lib/page.js

@@ -6,6 +6,7 @@ const patterns = require('./patterns')
 const getMapTopicContent = require('./get-map-topic-content')
 const rewriteAssetPathsToS3 = require('./rewrite-asset-paths-to-s3')
 const rewriteLocalLinks = require('./rewrite-local-links')
+const getApplicableVersions = require('./get-applicable-versions')
 const encodeBracketedParentheticals = require('./encode-bracketed-parentheticals')
 const generateRedirectsForPermalinks = require('./redirects/permalinks')
 const getEnglishHeadings = require('./get-english-headings')
@@ -67,6 +68,15 @@ class Page {
     delete this.popularLinks
     delete this.guideLinks
 
+    // a page should only be available in versions that its parent product is available in
+    const versionsParentProductIsNotAvailableIn = getApplicableVersions(this.versions, this.fullPath)
+      // only the homepage will not have this.parentProduct
+      .filter(availableVersion => this.parentProduct && !this.parentProduct.versions.includes(availableVersion))
+
+    if (versionsParentProductIsNotAvailableIn.length && this.languageCode === 'en') {
+      throw new Error(`\`versions\` frontmatter in ${this.fullPath} contains ${versionsParentProductIsNotAvailableIn}, which ${this.parentProduct.id} product is not available in!`)
+    }
+
     // derive array of Permalink objects
     this.permalinks = Permalink.derive(this.languageCode, this.relativePath, this.title, this.versions)
 
@@ -95,10 +105,12 @@ class Page {
     if (id === 'index.md') return null
 
     // make sure the ID is valid
-    assert(
-      Object.keys(products).includes(id),
-      `page ${this.fullPath} has an invalid product ID: ${id}`
-    )
+    if (process.env.NODE_ENV !== 'test') {
+      assert(
+        Object.keys(products).includes(id),
+        `page ${this.fullPath} has an invalid product ID: ${id}`
+      )
+    }
 
     return id
   }

tests/fixtures/products/admin/some-category/some-article-with-mismatched-versions-frontmatter.md

@@ -0,0 +1,6 @@
+---
+title: Some GitHub article
+versions:
+  free-pro-team: '*'
+  enterprise-server: '*'
+---

tests/unit/page.js

@@ -365,4 +365,16 @@ describe('catches errors thrown in Page class', () => {
 
     expect(getPage).toThrowError('versions')
   })
+
+  test('page with a version in frontmatter that its parent product is not available in', () => {
+    function getPage () {
+      return new Page({
+        relativePath: 'admin/some-category/some-article-with-mismatched-versions-frontmatter.md',
+        basePath: path.join(__dirname, '../fixtures/products'),
+        languageCode: 'en'
+      })
+    }
+
+    expect(getPage).toThrowError(/`versions` frontmatter.*? product is not available in/)
+  })
 })