fix: resolve devtools url after vitest config is resolved

resolves #548

src/module.ts

@@ -63,8 +63,6 @@ export default defineNuxtModule<NuxtVitestOptions>({
       })
     })
 
-    const PORT = await getPort({ port: 15555 })
-    const URL = `http://localhost:${PORT}/__vitest__/`
     let loaded = false
     let promise: Promise<any> | undefined
     let ctx: Vitest = undefined!
@@ -74,6 +72,8 @@ export default defineNuxtModule<NuxtVitestOptions>({
       nuxt.callHook('devtools:customTabs:refresh')
     }, 100)
 
+    let URL: string
+
     async function start() {
       const rawViteConfig = mergeConfig({}, await rawViteConfigPromise)
 
@@ -102,6 +102,11 @@ export default defineNuxtModule<NuxtVitestOptions>({
 
       const watchMode = !process.env.NUXT_VITEST_DEV_TEST && !isCI
 
+      // We resolve the path here to ensure the dev server is already running with the correct protocol
+      const PORT = await getPort({ port: 15555 })
+      const PROTOCOL = nuxt.options.devServer.https ? 'https' : 'http'
+      URL = `${PROTOCOL}://localhost:${PORT}/__vitest__/`
+
       // For testing dev mode in CI, maybe expose an option to user later
       const overrides: VitestConfig = watchMode
         ? {