Vue

new_feature
├── components
│   └── component.vue
│   └── ...
├── store
│  └── new_feature_store.js
├── index.js

//my_component.vue
<template>
  <div>
    <p>Prop1: {{ prop1 }}</p>
    <p>Prop2: {{ prop2 }}</p>
  </div>
</template>

<script>
export default {
  name: 'MyComponent',
  props: {
    prop1: {
      type: String,
      required: true
    },
    prop2: {
      type: Number,
      required: true
    }
  }
}
</script>

<div id="js-my-element" data-view-model='{"prop1": "my object", "prop2": 42 }'></div>

//index.js
import MyComponent from './my_component.vue'
import { initSimpleApp } from '~/helpers/init_simple_app_helper'

initSimpleApp('#js-my-element', MyComponent, { name: 'MyAppRoot' })

//my_component.vue
<template>
  <div>
    <p>Inject1: {{ inject1 }}</p>
    <p>Inject2: {{ inject2 }}</p>
  </div>
</template>

<script>
export default {
  name: 'MyComponent',
  inject: {
    inject1: {
      default: '',
    },
    inject2: {
      default: 0
    }
  },
}
</script>

<div id="js-my-element" data-provide='{"inject1": "my object", "inject2": 42 }'></div>

//index.js
import MyComponent from './my_component.vue'
import { initSimpleApp } from '~/helpers/init_simple_app_helper'

initSimpleApp('#js-my-element', MyComponent, { name: 'MyAppRoot' })

#js-vue-app{ data: { endpoint: 'foo' }}

// index.js
const el = document.getElementById('js-vue-app');

if (!el) return false;

const { endpoint } = el.dataset;

return new Vue({
  el,
  name: 'MyComponentRoot',
  render(createElement) {
    return createElement('my-component', {
      provide: {
        endpoint
      },
    });
  },
});

<script>
  export default {
    name: 'MyComponent',
    inject: ['endpoint'],
    ...
    ...
  };
</script>
<template>
  ...
  ...
</template>

// haml
#js-vue-app{ data: { endpoint: 'foo' }}

// index.js
const el = document.getElementById('js-vue-app');

if (!el) return false;

const { endpoint } = el.dataset;

return new Vue({
  el,
  name: 'MyComponentRoot',
  render(createElement) {
    return createElement('my-component', {
      props: {
        endpoint
      },
    });
  },
});

-# form.html.haml
= form_for user do |form|
  .js-user-form
    = form.text_field :name, class: 'form-control gl-form-input', data: { js_name: 'name' }
    = form.text_field :email, class: 'form-control gl-form-input', data: { js_name: 'email' }

// index.js
import Vue from 'vue';
import { parseRailsFormFields } from '~/lib/utils/forms';
import UserForm from './components/user_form.vue';

export const initUserForm = () => {
  const el = document.querySelector('.js-user-form');

  if (!el) {
    return null;
  }

  const fields = parseRailsFormFields(el);

  return new Vue({
    el,
    name: 'UserFormRoot',
    render(h) {
      return h(UserForm, {
        props: {
          fields,
        },
      });
    },
  });
};

<script>
// user_form.vue
import { GlButton, GlFormGroup, GlFormInput } from '@gitlab/ui';

export default {
  name: 'UserForm',
  components: { GlButton, GlFormGroup, GlFormInput },
  props: {
    fields: {
      type: Object,
      required: true,
    },
  },
};
</script>

<template>
  <div>
    <gl-form-group :label-for="fields.name.id" :label="__('Name')">
      <gl-form-input v-bind="fields.name" width="lg" />
    </gl-form-group>

    <gl-form-group :label-for="fields.email.id" :label="__('Email')">
      <gl-form-input v-bind="fields.email" type="email" width="lg" />
    </gl-form-group>

    <gl-button type="submit" category="primary" variant="confirm">{{ __('Update') }}</gl-button>
  </div>
</template>

return new Vue({
  el: '.js-vue-app',
  name: 'MyComponentRoot',
  render(createElement) {
    return createElement('my-component', {
      props: {
        avatarUrl: gl.avatarUrl,
      },
    });
  },
});

// 任意后代组件

import glAbilitiesMixin from '~/vue_shared/mixins/gl_abilities_mixin';

export default {
  // ...
  mixins: [glAbilitiesMixin()],
  // ...
  created() {
    if (this.glAbilities.someAbility) {
      // ...
    }
  },
}

// 任意后代组件

import glFeatureFlagsMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';

export default {
  // ...
  mixins: [glFeatureFlagsMixin()],
  // ...
  created() {
    if (this.glFeatures.myFlag) {
      // ...
    }
  },
}

visitUrlWithAlerts('/dashboard/groups', [
  {
    id: 'resource-building-in-background',
    message: 'Resource is being built in the background.',
    variant: 'info',
    persistOnPages: ['dashboard:groups:index'],
  },
])

<script>
  import { computed } from 'vue';

  export default {
    name: 'MyComponent',
    setup(props) {
      const doubleCount = computed(() => props.count*2)
    }
  }
</script>

// useCount.js
import { ref } from 'vue';

export function useCount(initialValue) {
  const count = ref(initialValue)

  function incrementCount() {
    count.value += 1
  }

  function decrementCount() {
    count.value -= 1
  }

  return { count, incrementCount, decrementCount }
}

// MyComponent.vue
import { useCount } from 'useCount'

export default {
  name: 'MyComponent',
  setup() {
    const { count, incrementCount, decrementCount } = useCount(5)

    return { count, incrementCount, decrementCount }
  }
}

// bad
const useAsyncLogic = () => {
  const action = async () => {
    await doSomething();
    onMounted(doSomethingElse);
  };
  return { action };
};

// OK
const useAsyncLogic = () => {
  const done = ref(false);
  onMounted(() => {
    watch(
      done,
      () => done.value && doSomethingElse(),
      { immediate: true },
    );
  });
  const action = async () => {
    await doSomething();
    done.value = true;
  };
  return { action };
};

const useSomeLogic = () => {
  doSomeLogic();
  getCurrentInstance().emit('done'); // bad
};

const done = () => emit('done');

const useSomeLogic = (done) => {
  doSomeLogic();
  done(); // good, 组合式函数不试图过于智能
}

import { GlLoadingIcon } from '@gitlab/ui';
import MockAdapter from 'axios-mock-adapter';
import { shallowMountExtended } from 'helpers/vue_test_utils_helper';
import axios from '~/lib/utils/axios_utils';
import App from '~/todos/app.vue';

const TEST_TODOS = [{ text: 'Lorem ipsum test text' }, { text: 'Lorem ipsum 2' }];
const TEST_NEW_TODO = 'New todo title';
const TEST_TODO_PATH = '/todos';

describe('~/todos/app.vue', () => {
  let wrapper;
  let mock;

  beforeEach(() => {
    // 重要：使用 axios-mock-adapter 来存根 axios API 请求
    mock = new MockAdapter(axios);
    mock.onGet(TEST_TODO_PATH).reply(200, TEST_TODOS);
    mock.onPost(TEST_TODO_PATH).reply(200);
  });

  afterEach(() => {
    // 重要：清理 axios mock 适配器
    mock.restore();
  });

  // 将组件设置与其协作者（例如 Vuex 和 axios）分开非常有帮助。
  const createWrapper = (props = {}) => {
    wrapper = shallowMountExtended(App, {
      propsData: {
        path: TEST_TODO_PATH,
        ...props,
      },
    });
  };
  // 辅助方法极大地有助于测试的可维护性和可读性。
  const findLoader = () => wrapper.findComponent(GlLoadingIcon);
  const findAddButton = () => wrapper.findByTestId('add-button');
  const findTextInput = () => wrapper.findByTestId('text-input');
  const findTodoData = () =>
    wrapper
      .findAllByTestId('todo-item')
      .wrappers.map((item) => ({ text: item.text() }));

  describe('当挂载并加载时', () => {
    beforeEach(() => {
      // 创建永不解析的请求
      mock.onGet(TEST_TODO_PATH).reply(() => new Promise(() => {}));
      createWrapper();
    });

    it('应显示加载状态', () => {
      expect(findLoader().exists()).toBe(true);
    });
  });

  describe('当 todos 已加载时', () => {
    beforeEach(() => {
      createWrapper();
      // 重要：此组件在挂载时异步获取数据，因此等待 Vue 模板更新
      return wrapper.vm.$nextTick();
    });

    it('不应显示加载', () => {
      expect(findLoader().exists()).toBe(false);
    });

    it('应渲染 todos', () => {
      expect(findTodoData()).toEqual(TEST_TODOS);
    });

    it('当添加 todo 时，应发布新 todo', async () => {
      findTextInput().vm.$emit('update', TEST_NEW_TODO);
      findAddButton().vm.$emit('click');

      await wrapper.vm.$nextTick();

      expect(mock.history.post.map((x) => JSON.parse(x.data))).toEqual([{ text: TEST_NEW_TODO }]);
    });
  });
});

// 假设 SomeButton 渲染: <button>Some button</button>
wrapper = mount(SomeButton);

...
it('应触发点击事件', () => {
  const btn = wrapper.find('button')

  btn.trigger('click');
  ...
})

wrapper = shallowMount(DropdownItem);

...

it('应触发 itemClicked 事件', () => {
  DropdownItem.vm.$emit('itemClicked');
  ...
})

const findButton = () => wrapper.findComponent(GlButton);

// bad
findButton().trigger('click');

// good
findButton().vm.$emit('click');

<template>
  <div class="content">
    <gl-loading-icon v-if="isLoading" />
    <template v-else>
      <div
        v-for="todo in todos"
        :key="todo.id"
        :class="{ 'gl-strike': todo.isDone }"
        data-testid="todo-item"
      >{{ todo.text }}</div>
      <footer class="gl-border-t-1 gl-mt-3 gl-pt-3">
        <gl-form-input
          type="text"
          v-model="todoText"
          data-testid="text-input"
        >
        <gl-button
          variant="confirm"
          data-testid="add-button"
          @click="addTodo"
        >Add</gl-button>
      </footer>
    </template>
  </div>
</template>