Vue.js/test/unit/features/options/inject.spec.js

import Vue from 'vue'

describe('Options provide/inject', () => {
  let injected
  const injectedComp = {
    inject: ['foo', 'bar'],
    render () {},
    created () {
      injected = [this.foo, this.bar]
    }
  }

  beforeEach(() => {
    injected = null
  })

  it('should work', () => {
    new Vue({
      template: `<child/>`,
      provide: {
        foo: 1,
        bar: 2
      },
      components: {
        child: {
          template: `<injected-comp/>`,
          components: {
            injectedComp
          }
        }
      }
    }).$mount()

    expect(injected).toEqual([1, 2])
  })

  it('should use closest parent', () => {
    new Vue({
      template: `<child/>`,
      provide: {
        foo: 1,
        bar: 2
      },
      components: {
        child: {
          provide: {
            foo: 3
          },
          template: `<injected-comp/>`,
          components: {
            injectedComp
          }
        }
      }
    }).$mount()

    expect(injected).toEqual([3, 2])
  })

  it('provide function', () => {
    new Vue({
      template: `<child/>`,
      data: {
        a: 1,
        b: 2
      },
      provide () {
        return {
          foo: this.a,
          bar: this.b
        }
      },
      components: {
        child: {
          template: `<injected-comp/>`,
          components: {
            injectedComp
          }
        }
      }
    }).$mount()

    expect(injected).toEqual([1, 2])
  })

  it('inject with alias', () => {
    const injectAlias = {
      inject: {
        baz: 'foo',
        qux: 'bar'
      },
      render () {},
      created () {
        injected = [this.baz, this.qux]
      }
    }

    new Vue({
      template: `<child/>`,
      provide: {
        foo: 1,
        bar: 2
      },
      components: {
        child: {
          template: `<inject-alias/>`,
          components: {
            injectAlias
          }
        }
      }
    }).$mount()

    expect(injected).toEqual([1, 2])
  })

  it('self-inject', () => {
    const vm = new Vue({
      provide: {
        foo: 1
      },
      inject: ['foo']
    })

    expect(vm.foo).toBe(1)
  })
})