test: fix global-api tests

Author: wangsongc

Diff for: generator/codemods/global-api/__testfixtures__/basic.output.js

@@ -1,4 +1,5 @@
 import { createApp } from 'vue';
 import App from './App.vue';
 
-createApp(App).mount('#app');
+const app = createApp(App);
+app.mount('#app');

Diff for: generator/codemods/global-api/__testfixtures__/custom-root-prop.output.js

@@ -1,7 +1,9 @@
 import { createApp, h } from 'vue';
 import App from './App.vue';
 
-createApp({
+const app = createApp({
   myOption: 'hello!',
   render: () => h(App),
-}).mount('#app');
+});
+
+app.mount('#app');

Diff for: generator/codemods/global-api/__testfixtures__/vue-router.output.js

@@ -2,4 +2,5 @@ import { createApp } from 'vue';
 import App from './App.vue';
 import router from './router';
 
-createApp(App).use(router).mount('#app');
+const app = createApp(App).use(router);
+app.mount('#app');

Diff for: generator/codemods/global-api/__testfixtures__/vuex.output.js

@@ -3,6 +3,7 @@ import App from './App.vue';
 import store from './store';
 import anotherStore from './another-store';
 
-createApp(App).use(store).mount('#app');
-
-createApp(App).use(anotherStore).mount('#app');
+const app = createApp({}).use(h => h(App));
+app.mount('#app');
+const app = createApp({}).use(h => h(App));
+app.mount('#app');