POC extending without plugin

src/config.ts

@@ -0,0 +1,6 @@
+export const config = {
+  plugins: {
+    VueWrapper: {} as any,
+    DOMWrapper: {}
+  }
+}

src/index.ts

@@ -1,4 +1,7 @@
 import { mount } from './mount'
 import { RouterLinkStub } from './components/RouterLinkStub'
+import { VueWrapper } from './vue-wrapper'
 
-export { mount, RouterLinkStub }
+import { config } from './config'
+
+export { mount, RouterLinkStub, VueWrapper, config }

src/vue-wrapper.ts

@@ -1,5 +1,6 @@
 import { ComponentPublicInstance, nextTick } from 'vue'
 import { ShapeFlags } from '@vue/shared'
+import { config } from './config'
 
 import { DOMWrapper } from './dom-wrapper'
 import { WrapperAPI } from './types'
@@ -21,6 +22,13 @@ export class VueWrapper implements WrapperAPI {
     this.__setProps = setProps
     this.componentVM = this.vm.$refs['VTU_COMPONENT'] as ComponentPublicInstance
     this.__emitted = events
+
+    // plugins hook
+    Object.entries(config.plugins.VueWrapper).forEach(
+      ([name, handler]: [string, () => any]) => {
+        this[name] = handler.bind(this)
+      }
+    )
   }
 
   private get appRootNode() {

tests/features/plugins.spec.ts

@@ -0,0 +1,32 @@
+import { mount, VueWrapper, config } from '../../src'
+import Hello from '../components/Hello.vue'
+// add a method to the VueWrapper
+declare module '../../src/vue-wrapper' {
+  interface VueWrapper {
+    name(): string
+
+    lowerCaseName(): string[]
+  }
+}
+
+VueWrapper.prototype.name = function () {
+  return this.componentVM.$.type.name
+}
+
+config.plugins.VueWrapper.lowerCaseName = function lowerCaseName(
+  this: VueWrapper
+) {
+  return this.name().toLocaleLowerCase()
+}
+
+describe('Plugin', () => {
+  it('adds name property', () => {
+    const wrapper = mount(Hello)
+    expect(wrapper.name()).toEqual('Hello')
+  })
+
+  it('adds loweCase name property', () => {
+    const wrapper = mount(Hello)
+    expect(wrapper.lowerCaseName()).toEqual('hello')
+  })
+})