chore(compat): introduce Vue3 testing infrastructure

Add basic setup for running tests with vue3 compat

Author: xanf

jest.config.js

@@ -1,9 +1,18 @@
+const useVue2 = 'USE_VUE2' in process.env
+
+const moduleNameMapper = useVue2
+  ? {}
+  : {
+      '^vue$': '@vue/compat',
+      '^@vue/test-utils$': '@vue/test-utils-vue3'
+    }
+
 module.exports = {
   testRegex: 'spec.js$',
   moduleFileExtensions: ['js', 'vue'],
+  moduleNameMapper,
   transform: {
-    '^.+\\.js$': 'babel-jest',
-    '.*\\.(vue)$': 'vue-jest'
+    '^.+\\.js$': 'babel-jest'
   },
   coverageDirectory: './coverage/',
   testEnvironmentOptions: {

package.json

@@ -99,7 +99,10 @@
     "@nuxtjs/robots": "^2.5.0",
     "@nuxtjs/sitemap": "^2.4.0",
     "@testing-library/jest-dom": "^5.12.0",
+    "@vue/compat": "^3.2.22",
+    "@vue/compiler-dom": "^3.2.22",
     "@vue/test-utils": "^1.3.0",
+    "@vue/test-utils-vue3": "npm:@vue/test-utils@^2.0.0",
     "autoprefixer": "^10.2.5",
     "babel-core": "^7.0.0-bridge.0",
     "babel-eslint": "^10.1.0",
@@ -148,10 +151,10 @@
     "standard-version": "^9.3.0",
     "terser": "^5.7.0",
     "vue": "^2.6.12",
-    "vue-jest": "^3.0.7",
     "vue-router": "^3.5.1",
     "vue-server-renderer": "^2.6.12",
-    "vue-template-compiler": "^2.6.12"
+    "vue-template-compiler": "^2.6.12",
+    "vue-test-utils-compat": "^0.0.1"
   },
   "keywords": [
     "Bootstrap",

tests/setup.js

@@ -1,6 +1,18 @@
 import '@testing-library/jest-dom'
-import { config as vtuConfig } from '@vue/test-utils'
+import Vue from 'vue'
+import * as VTU from '@vue/test-utils'
+import { installCompat as installVTUCompat, fullCompatConfig } from 'vue-test-utils-compat'
+
+const useVue2 = 'USE_VUE2' in process.env
+if (!useVue2) {
+  Vue.configureCompat({
+    MODE: 2
+  })
+
+  const compatH = new Vue({}).$createElement
+  installVTUCompat(VTU, fullCompatConfig, compatH)
+}
 
 // Don't stub `<transition>` and `<transition-group>` components
-vtuConfig.stubs.transition = false
-vtuConfig.stubs['transition-group'] = false
+VTU.config.stubs.transition = false
+VTU.config.stubs['transition-group'] = false