From eb3bc3775a3a0fe6d33c6bd928435f0f8aa6ae8e Mon Sep 17 00:00:00 2001
From: Harlan Wilton <harlan@harlanzw.com>
Date: Thu, 21 Dec 2023 15:13:49 +1100
Subject: [PATCH] feat: implement `fallbackTitle` as separate plugin

---
 module/src/module.ts                | 11 +++++++++
 module/src/runtime/plugin/titles.ts | 36 +++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 module/src/runtime/plugin/titles.ts

diff --git a/module/src/module.ts b/module/src/module.ts
index b259c22a..1df0039f 100644
--- a/module/src/module.ts
+++ b/module/src/module.ts
@@ -12,6 +12,12 @@ import { installNuxtSiteConfig } from 'nuxt-site-config-kit'
 import { version } from '../package.json'
 
 export interface ModuleOptions {
+  /**
+   * Will ensure a title is always set by providing a fallback title based on the casing the last slug segment.
+   *
+   * @default true
+   */
+  fallbackTitle?: boolean
   /**
    * Will set up a number of defaults for meta tags and Schema.org, if the modules and config are available.
    *
@@ -95,6 +101,11 @@ export default defineNuxtModule<ModuleOptions>({
         src: resolve('./runtime/plugin/defaults'),
       })
     }
+    if (config.fallbackTitle) {
+      addPlugin({
+        src: resolve('./runtime/plugin/titles'),
+      })
+    }
 
     // if user disables certain modules we need to pollyfill the imports
     const polyfills: Record<string, string[]> = {
diff --git a/module/src/runtime/plugin/titles.ts b/module/src/runtime/plugin/titles.ts
new file mode 100644
index 00000000..6db41189
--- /dev/null
+++ b/module/src/runtime/plugin/titles.ts
@@ -0,0 +1,36 @@
+import { defineNuxtPlugin } from 'nuxt/app'
+import type { UseHeadOptions } from '@unhead/vue'
+import { withoutTrailingSlash } from 'ufo'
+import {
+  computed,
+  useHead,
+  useRoute,
+} from '#imports'
+
+function titleCase(s: string) {
+  return s
+    .replaceAll('-', ' ')
+    .replace(/\w\S*/g, w => w.charAt(0).toUpperCase() + w.substr(1).toLowerCase())
+}
+
+export default defineNuxtPlugin({
+  name: 'nuxt-seo:fallback-titles',
+  setup() {
+    const route = useRoute()
+    const title = computed(() => {
+      if (typeof route.meta?.title === 'string')
+        return route.meta?.title
+      // if no title has been set then we should use the last segment of the URL path and title case it
+      const path = withoutTrailingSlash(route.path || '/')
+      const lastSegment = path.split('/').pop()
+      return lastSegment ? titleCase(lastSegment) : null
+    })
+
+    const minimalPriority: UseHeadOptions = {
+      // give nuxt.config values higher priority
+      tagPriority: 101,
+    }
+
+    useHead({ title }, minimalPriority)
+  },
+})