fix(titleTemplate): allow titleTemplate to resolve the title

package.json

@@ -43,8 +43,8 @@
   },
   "dependencies": {
     "@vueuse/shared": "^9.3.0",
-    "@zhead/schema": "^0.9.0",
-    "@zhead/schema-vue": "^0.9.0"
+    "@zhead/schema": "^0.9.5",
+    "@zhead/schema-vue": "^0.9.5"
   },
   "devDependencies": {
     "@antfu/eslint-config": "^0.27.0",

src/types/index.ts

@@ -29,7 +29,7 @@ export interface HeadEntry<T extends MergeHead = {}> {
   id: number
 }
 
-export type TagKeys = keyof Omit<HeadObjectPlain, 'titleTemplate'>
+export type TagKeys = keyof HeadObjectPlain
 
 export interface HeadTag {
   tag: TagKeys

src/utils.ts

@@ -3,7 +3,6 @@ import { unref } from 'vue'
 import type { MergeHead } from '@zhead/schema'
 import type {
   HeadEntry,
-  HeadObjectPlain,
   HeadTag,
   HeadTagOptions,
   ResolvedUseHeadInput,
@@ -41,7 +40,7 @@ export const sortTags = (aTag: HeadTag, bTag: HeadTag) => {
 export const tagDedupeKey = <T extends HeadTag>(tag: T) => {
   const { props, tag: tagName, options } = tag
   // must only be a single base so we always dedupe
-  if (tagName === 'base' || tagName === 'title')
+  if (tagName === 'base' || tagName === 'title' || tagName === 'titleTemplate')
     return tagName
 
   // support only a single canonical
@@ -104,7 +103,6 @@ const resolveTag = (name: TagKeys, input: Record<string, any>, e: HeadEntry): He
     props: {},
     runtime: {
       entryId: e.id,
-      position: 0,
     },
     // tag inherits options from useHead registration
     options: {
@@ -143,12 +141,20 @@ const resolveTag = (name: TagKeys, input: Record<string, any>, e: HeadEntry): He
 
 export const headInputToTags = (e: HeadEntry) => {
   return Object.entries(e.input)
-    .filter(([k, v]) => typeof v !== 'undefined' && v !== null && k !== 'titleTemplate')
+    .filter(([, v]) => typeof v !== 'undefined')
     .map(([key, value]) => {
       return (Array.isArray(value) ? value : [value]).map((props) => {
         switch (key) {
           case 'title':
-            return resolveTag(key, { children: props }, e)
+          case 'titleTemplate':
+            // titleTemplate is a fake tag so we can dedupe it, this will be removed
+            return <HeadTag> {
+              tag: key,
+              children: props,
+              props: {},
+              runtime: { entryId: e.id },
+              options: e.options,
+            }
           case 'base':
           case 'meta':
           case 'link':
@@ -169,11 +175,11 @@ export const headInputToTags = (e: HeadEntry) => {
 }
 
 const renderTitleTemplate = (
-  template: Required<HeadObjectPlain>['titleTemplate'],
+  template: string | ((title?: string) => string | null),
   title?: string,
-): string => {
+): string | null => {
   if (template == null)
-    return ''
+    return title || null
   if (typeof template === 'function')
     return template(title)
 
@@ -185,11 +191,6 @@ export const resolveHeadEntriesToTags = (entries: HeadEntry[]) => {
 
   const resolvedEntries = resolveHeadEntries(entries)
 
-  const titleTemplate = resolvedEntries
-    .map(i => i.input.titleTemplate)
-    .reverse()
-    .find(i => i != null)
-
   resolvedEntries.forEach((entry, entryIndex) => {
     const tags = headInputToTags(entry)
     tags.forEach((tag, tagIdx) => {
@@ -199,20 +200,47 @@ export const resolveHeadEntriesToTags = (entries: HeadEntry[]) => {
       // ideally we'd use the total tag count but this is too hard to calculate with the current reactivity
       tag.runtime.position = entryIndex * 10000 + tagIdx
 
-      // resolve titles
-      if (titleTemplate && tag.tag === 'title') {
-        tag.children = renderTitleTemplate(
-          titleTemplate,
-          tag.children,
-        )
-      }
-
       // Remove tags with the same key
       deduping[tagDedupeKey(tag)] = tag
     })
   })
 
-  return Object.values(deduping)
+  let resolvedTags = Object.values(deduping)
     .sort((a, b) => a.runtime!.position! - b.runtime!.position!)
     .sort(sortTags)
+
+  // resolve title
+  const titleTemplateIdx = resolvedTags.findIndex(i => i.tag === 'titleTemplate')
+  const titleIdx = resolvedTags.findIndex(i => i.tag === 'title')
+  if (titleIdx !== -1 && titleTemplateIdx !== -1) {
+    const newTitle = renderTitleTemplate(
+      resolvedTags[titleTemplateIdx].children!,
+      resolvedTags[titleIdx].children,
+    )
+    if (newTitle !== null) {
+      resolvedTags[titleIdx].children = newTitle || resolvedTags[titleIdx].children
+    }
+    else {
+      // remove the title
+      resolvedTags = resolvedTags.filter((_, i) => i !== titleIdx)
+    }
+    // remove the title template
+    resolvedTags = resolvedTags.filter((_, i) => i !== titleTemplateIdx)
+  }
+  // titleTemplate is set but title is not set, convert to a title
+  else if (titleTemplateIdx !== -1) {
+    const newTitle = renderTitleTemplate(
+      resolvedTags[titleTemplateIdx].children!,
+    )
+    if (newTitle !== null) {
+      resolvedTags[titleTemplateIdx].children = newTitle
+      resolvedTags[titleTemplateIdx].tag = 'title'
+    }
+    else {
+      // remove the title template
+      resolvedTags = resolvedTags.filter((_, i) => i !== titleTemplateIdx)
+    }
+  }
+
+  return resolvedTags
 }

tests/reactivity-types.test.ts

@@ -1,5 +1,6 @@
 import { computed, createSSRApp, ref } from 'vue'
 import { renderToString } from '@vue/server-renderer'
+import type { UseHeadInput } from '@vueuse/head'
 import { createHead, renderHeadToString, useHead } from '../src'
 import type { HeadObjectPlain } from '../src/types'
 import { ssrRenderHeadToString } from './shared/utils'
@@ -154,7 +155,7 @@ describe('reactivity', () => {
 
   test('computed getter entries', async () => {
     const test = ref('test')
-    const input = {
+    const input: UseHeadInput = {
       title: () => 'my title',
       script: () => {
         return [

tests/title-template.test.ts

@@ -0,0 +1,96 @@
+import { useHead } from '../src'
+import { ssrRenderHeadToString } from './shared/utils'
+
+describe('titleTemplate', () => {
+  test('string replace', async () => {
+    const titleTemplate = '%s - my template'
+    const headResult = await ssrRenderHeadToString(() => {
+      useHead({
+        titleTemplate,
+        title: 'test',
+      })
+    })
+    expect(headResult.headTags).toMatchInlineSnapshot(
+      '"<title>test - my template</title><meta name=\\"head:count\\" content=\\"0\\">"',
+    )
+  })
+  test('fn replace', async () => {
+    const titleTemplate = (title?: string) => `${title} - my template`
+    const headResult = await ssrRenderHeadToString(() => {
+      useHead({
+        titleTemplate,
+        title: 'test',
+      })
+    })
+    expect(headResult.headTags).toMatchInlineSnapshot(
+      '"<title>test - my template</title><meta name=\\"head:count\\" content=\\"0\\">"',
+    )
+  })
+  test('titleTemplate as title', async () => {
+    const titleTemplate = (title?: string) => title ? `${title} - Template` : 'Default Title'
+    const headResult = await ssrRenderHeadToString(() => {
+      useHead({
+        titleTemplate,
+        title: null,
+      })
+    })
+    expect(headResult.headTags).toMatchInlineSnapshot(
+      '"<title>Default Title</title><meta name=\\"head:count\\" content=\\"0\\">"',
+    )
+  })
+  test('reset title template', async () => {
+    const titleTemplate = (title?: string) => title ? `${title} - Template` : 'Default Title'
+    const headResult = await ssrRenderHeadToString(() => {
+      useHead({
+        titleTemplate,
+      })
+      useHead({
+        // resets the titleTemplate
+        titleTemplate: null,
+        title: 'page title',
+      })
+    })
+    expect(headResult.headTags).toMatchInlineSnapshot(
+      '"<title>page title</title><meta name=\\"head:count\\" content=\\"0\\">"',
+    )
+  })
+
+  test('nested title template', async () => {
+    const titleTemplate = (title?: string | null) => title ? `${title} - Template` : 'Default Title'
+    const headResult = await ssrRenderHeadToString(() => {
+      useHead({
+        titleTemplate,
+      })
+      useHead({
+        titleTemplate: null,
+      })
+    })
+    expect(headResult.headTags).toMatchInlineSnapshot(
+      '"<meta name=\\"head:count\\" content=\\"0\\">"',
+    )
+  })
+
+  test('null fn return', async () => {
+    const titleTemplate = (title?: string | null) => title === 'test' ? null : `${title} - Template`
+    const headResult = await ssrRenderHeadToString(() => {
+      useHead({
+        titleTemplate,
+        title: 'test',
+      })
+    })
+    expect(headResult.headTags).toMatchInlineSnapshot(
+      '"<meta name=\\"head:count\\" content=\\"0\\">"',
+    )
+  })
+
+  test('empty title', async () => {
+    const headResult = await ssrRenderHeadToString(() => {
+      useHead({
+        title: '',
+      })
+    })
+    expect(headResult.headTags).toMatchInlineSnapshot(
+      '"<title></title><meta name=\\"head:count\\" content=\\"0\\">"',
+    )
+  })
+})

tests/vue-ssr.test.tsx

@@ -49,7 +49,9 @@ describe('vue ssr', () => {
     const app = createSSRApp({
       async setup() {
         const title = ref('initial title')
-        useHead({ title })
+        useHead({
+          title,
+        })
         await new Promise(resolve => setTimeout(resolve, 200))
         title.value = 'new title'
         return () => <div>hi</div>
@@ -121,18 +123,21 @@ describe('vue ssr', () => {
   })
 
   test('script key', async () => {
-    const headResult = await ssrRenderHeadToString(() => useHead({
-      script: [
-        {
-          key: 'my-script',
-          innerHTML: 'console.log(\'A\')',
-        },
-        {
-          key: 'my-script',
-          innerHTML: 'console.log(\'B\')',
-        },
-      ],
-    }))
+    const headResult = await ssrRenderHeadToString(() =>
+      useHead({
+        script: [
+          {
+            src: 'test',
+            key: 'my-script',
+            innerHTML: 'console.log(\'A\')',
+          },
+          {
+            key: 'my-script',
+            innerHTML: 'console.log(\'B\')',
+          },
+        ],
+      }),
+    )
 
     expect(headResult.headTags).toMatchInlineSnapshot(
       '"<script>console.log(\'B\')</script><meta name=\\"head:count\\" content=\\"1\\">"',