chore: disable module when head as function (#143)

src/module.ts

@@ -52,6 +52,13 @@ export default defineNuxtModule<ModuleOptions>({
     // @ts-ignore
     const head = (nuxt.options.app.head || nuxt.options.head) as NuxtAppHead
 
+    // disable module when head is a function
+    if (typeof head === 'function') {
+      logger.warn('This module does not work with `head` as function.')
+
+      return
+    }
+
     // merge fonts from valid head link
     fontsParsed.push(...head.link
       .filter(link => isValidURL(String(link.href)))

test/disable.test.ts

@@ -0,0 +1,30 @@
+import { describe, test, expect, vi, afterAll } from 'vitest'
+import { setup } from '@nuxt/test-utils'
+
+describe('disable', async () => {
+  const spyStderr = vi.spyOn(process.stderr, 'write').mockImplementation(() => undefined!)
+
+  afterAll(() => {
+    spyStderr.mockRestore()
+  })
+
+  await setup({
+    nuxtConfig: {
+      app: {
+        // @ts-ignore
+        head: () => {}
+      },
+      googleFonts: {
+        families: {
+          Roboto: true
+        }
+      }
+    }
+  })
+
+  test('should warn if head as function', () => {
+    expect(spyStderr).toBeCalledTimes(1)
+    const output = spyStderr.mock.calls[0][0].toString()
+    expect(output).contains('[warn] [nuxt:google-fonts] This module does not work with `head` as function.')
+  })
+})