fix: reinitialise global setup callbacks on each request

closes #270

src/hooks.ts

@@ -9,7 +9,7 @@ type SetupFunction = (
   ctx: SetupContext
 ) => void | Record<any, any>
 
-const globalSetup = new Set<SetupFunction>()
+let globalSetup: Set<SetupFunction>
 
 /**
  * Run a callback function in the global setup function. This should be called from a Nuxt plugin.
@@ -34,6 +34,7 @@ export const onGlobalSetup = (fn: SetupFunction) => {
  */
 export const globalPlugin: Plugin = context => {
   const { setup } = context.app
+  globalSetup = new Set<SetupFunction>()
   context.app.setup = (...args) => {
     let result = {}
     if (setup instanceof Function) {

test/e2e/hooks.ts

@@ -5,14 +5,17 @@ import { navigateTo, expectOnPage } from './helpers'
 fixture`onGlobalSetup`
 
 const assertions = async () => {
-  await expectOnPage('global setup was run on server')
-  await expectOnPage('global setup was run on client')
+  await expectOnPage('global setup was run 1 times on server')
+  await expectOnPage('global setup was run 1 times on client')
   await expectOnPage('globally injected value was received')
 }
 
 test('Runs plugin on server side page', async () => {
   await navigateTo('/hooks')
   await assertions()
+
+  await navigateTo('/hooks')
+  await assertions()
 })
 
 test('Runs plugin on client rendered page', async t => {

test/fixture/pages/hooks.vue

@@ -1,9 +1,9 @@
 <template>
   <blockquote>
     <p>
-      <code>global setup was {{ ranSsr ? 'run' : 'not run' }} on server</code>
+      <code>global setup was {{ ranSsr ? 'run' : 'not run' }} {{ ranSsr }} times on server</code>
       <br />
-      <code>global setup was {{ ran ? 'run' : 'not run' }} on client</code>
+      <code>global setup was {{ ran ? 'run' : 'not run' }} {{ ran }} times on client</code>
       <br />
       <code>
         globally injected value was

test/fixture/plugins/global.js

@@ -1,12 +1,15 @@
 import { onGlobalSetup, provide, ref, ssrRef } from '@nuxtjs/composition-api'
 
-export const ranSsr = ssrRef(false)
-export const ran = ref(false)
+export const ranSsr = ssrRef(0)
+export const ran = ref(0)
 
 export default () => {
+  ran.value = 0
+  if (process.server) ranSsr.value = 0
+
   onGlobalSetup(() => {
-    ran.value = true
-    ranSsr.value = true
+    ran.value++
+    if (process.server) ranSsr.value++
 
     provide('globalKey', true)