vue3 testing library - How to use globalProperties in tests - vue.js

Question

I am new to Vue and followed the recommendation to use vue testing library. The only issue is I can't seem to find a way to inject my code into globalProperties in render function.
Does anyone know of an example where I can inject or mock it out?
main.js
app.config.globalProperties.$globals = globalMethods
...
const app = createApp(App)
app.config.globalProperties.$globals = globalMethods
app.config.globalProperties.$globalVars = globalVars
app.component("font-awesome-icon", fontawesome)
app.use(applicationStore);
app.use (Hotjar, hotjarConfig)
app.use(i18n)
app.use(router)
app.mount('#app')
From my vue component in create I am able to call
Component.vue
let formatedObj = this.$globals.maskValues(this.inputValue, this.inputType, this);
...
,
created() {
let formatedObj = this.$globals.maskValues(this.inputValue, this.inputType, this);
this.myInputValue = formatedObj.formatedString;
this.formatedCharacterCount = formatedObj.formatedCharacterCount;
this.prevValue = this.myInputValue;
},
...
tesst.spec.js
import { render } from '#testing-library/vue'
import FormatedNumericInput from '#/components/Component.vue'
import {globalMethods} from'#/config/global-methods'
const label = 'Price'
const initSettings = {
props: {
inputId: 'testInputId1',
labelTxt: label
}
};
beforeEach(() => {
});
test('a simple string that defines your test', () => {
const { getByLabelText } = render(FormatedNumericInput, initSettings)
const input = getByLabelText(label)
// testing logic
expect(input != null).toBe(true)
expect(FormatedNumericInput != null).toBe(true)
})
** ERROR **
TypeError: Cannot read property 'maskValues' of undefined
85 | },
86 | created() {
> 87 | let formatedObj = this.$globals.maskValues(this.inputValue, this.inputType, this);
| ^
88 | this.myInputValue = formatedObj.formatedString;
89 | this.formatedCharacterCount = formatedObj.formatedCharacterCount;
90 | this.prevValue = this.myInputValue;
at Proxy.created (src/components/FormatedNumericInput.vue:87:37)

Answer 1

The second argument of render() is passed to #vue/test-utils mount(), so you could include the global.mocks mounting option to mock $globals.maskValues:
const { getByLabelText } = render(FormatedNumericInput, {
...initSettings,
global: {
mocks: {
$globals: {
maskValues: (inputValue, inputType) => {
const formatedString = globalFormatValue(inputValue) // declared elsewhere
return {
formatedString,
formatedCharacterCount: formatedString.length,
}
}
}
}
}
})

Answer 2

This is my solution in actual Vue3/Vite/Vitest environment, I set some mocks globally, so I don't need to in every test suite.
// vitest.config.ts
import { mergeConfig } from 'vite';
import { defineConfig } from 'vitest/config';
import viteConfig from './vite.config';
export default defineConfig(
mergeConfig(viteConfig, { // extending app vite config
test: {
setupFiles: ['tests/unit.setup.ts'],
environment: 'jsdom',
}
})
);
// tests/unit.setup.ts
import { config } from "#vue/test-utils"
config.global.mocks = {
$t: tKey => tKey; // just return translation key
};
so for you it will be something like
config.global.mocks = {
$globals: {
maskValues: (inputValue, inputType) => {
// ...implementation
return {
formatedString,
formatedCharacterCount,
}
}
}
}