tests: add useNodesInitialized test

tests/cypress/component/4-composables/useNodesInitialized.cy.ts

@@ -0,0 +1,56 @@
+import { defineComponent, h, watch } from 'vue'
+import { useNodesInitialized } from '@vue-flow/core'
+import { getElements } from '../../utils'
+
+const { nodes } = getElements()
+
+const ComposableTester = defineComponent({
+  emits: ['change'],
+  setup(_, { emit }) {
+    const nodesInitialized = useNodesInitialized()
+
+    watch(
+      nodesInitialized,
+      (value) => {
+        emit('change', value)
+      },
+      { immediate: true },
+    )
+
+    return 'Composable Tester'
+  },
+})
+
+describe('Composable: `useNodesInitialized`', () => {
+  it('should return that nodes are initialized', () => {
+    const onChangeSpy = cy.spy().as('onChangeSpy')
+
+    cy.vueFlow(
+      {
+        nodes,
+      },
+      {},
+      {
+        default: () => h(ComposableTester, { onChange: onChangeSpy }),
+      },
+    )
+
+    cy.get('@onChangeSpy').should('have.been.calledWith', true)
+  })
+
+  it('should return that nodes are not initialized', () => {
+    const onChangeSpy = cy.spy().as('onChangeSpy')
+
+    cy.vueFlow(
+      {
+        nodes: [],
+      },
+      {},
+      {
+        default: () => h(ComposableTester, { onChange: onChangeSpy }),
+      },
+    )
+
+    cy.get('@onChangeSpy').should('have.been.calledWith', false)
+  })
+})