Validate links to headings inside of partials (#2174)

Author: NWylynko

package-lock.json

@@ -29,6 +29,7 @@
     "remark-mdx": "^3.0.1",
     "tsx": "^4.19.2",
     "typescript": "^5.7.3",
+    "unist-util-map": "^4.0.0",
     "unist-util-visit": "^5.0.0",
     "vfile": "^6.0.1",
     "vfile-reporter": "^8.0.0",

package.json

@@ -388,6 +388,53 @@ title: Simple Test
 
     expect(output).toContain(`warning <Include /> prop "src" must start with "_partials/"`)
   })
+
+  test('Should validate heading within a partial', async () => {
+    const { tempDir } = await createTempFiles([
+      {
+        path: './docs/manifest.json',
+        content: JSON.stringify({
+          navigation: [
+            [{ title: 'Simple Test', href: '/docs/test-page-1' }],
+            [{ title: 'Test Page 2', href: '/docs/test-page-2' }],
+          ],
+        }),
+      },
+      {
+        path: './docs/_partials/test-partial.mdx',
+        content: `# Heading`,
+      },
+      {
+        path: './docs/test-page-1.mdx',
+        content: `---
+title: Test Page 1
+description: This is a test page
+---
+
+<Include src="_partials/test-partial" />`,
+      },
+      {
+        path: './docs/test-page-2.mdx',
+        content: `---
+title: Test Page 2
+description: This is a test page
+---
+
+[Test Page](/docs/test-page-1#heading)`,
+      },
+    ])
+
+    const output = await build(
+      createConfig({
+        ...baseConfig,
+        basePath: tempDir,
+        validSdks: ['react'],
+      }),
+    )
+
+    expect(output).not.toContain(`warning Hash "heading" not found in /docs/test-page-1`)
+    expect(output).toBe('')
+  })
 })
 
 describe('Link Validation and Processing', () => {

scripts/build-docs.test.ts

@@ -15,6 +15,7 @@ import path from 'node:path'
 import remarkMdx from 'remark-mdx'
 import { remark } from 'remark'
 import { visit as mdastVisit } from 'unist-util-visit'
+import { map as mdastMap } from 'unist-util-map'
 import remarkFrontmatter from 'remark-frontmatter'
 import yaml from 'yaml'
 import { slugifyWithCounter } from '@sindresorhus/slugify'
@@ -682,6 +683,38 @@ const parseInMarkdownFile =
           return
         })
       })
+      .process({
+        path: `${href.substring(1)}.mdx`,
+        value: fileContent,
+      })
+
+    // This needs to be done separately as some further validation expects the partials to not be embedded
+    // but we need to embed it to get all the headings to check
+    await markdownProcessor()
+      // Embed the partial
+      .use(() => (tree, vfile) => {
+        return mdastMap(tree, (node) => {
+          const partialSrc = extractComponentPropValueFromNode(config, node, vfile, 'Include', 'src', true, filePath)
+
+          if (partialSrc === undefined) return node
+
+          if (partialSrc.startsWith('_partials/') === false) {
+            safeMessage(config, vfile, filePath, 'include-src-not-partials', [], node.position)
+            return node
+          }
+
+          const partial = partials.find(
+            (partial) => `_partials/${partial.path}` === `${removeMdxSuffix(partialSrc)}.mdx`,
+          )
+
+          if (partial === undefined) {
+            safeMessage(config, vfile, filePath, 'partial-not-found', [removeMdxSuffix(partialSrc)], node.position)
+            return node
+          }
+
+          return Object.assign(node, partial.node)
+        })
+      })
       // extract out the headings to check hashes in links
       .use(() => (tree) => {
         mdastVisit(