如何使用Ginkgo对HTTP请求进行单元测试？

i have just started learning to write unit tests for the http requests, i went through several blogs but i didn't understood how to write tests for this using Ginkgo.

func getVolDetails(volName string, obj interface{}) error {
addr := os.Getenv("SOME_ADDR")
if addr == "" {
    err := errors.New("SOME_ADDR environment variable not set")
    fmt.Println(err)
    return err
}
url := addr + "/path/to/somepage/" + volName
client := &http.Client{
    Timeout: timeout,
}
resp, err := client.Get(url)
if resp != nil {
    if resp.StatusCode == 500 {
        fmt.Printf("VSM %s not found
", volName)
        return err
    } else if resp.StatusCode == 503 {
        fmt.Println("server not reachable")
        return err
    }
} else {
    fmt.Println("server not reachable")
    return err
}

if err != nil {
    fmt.Println(err)
    return err
}
defer resp.Body.Close()

return json.NewDecoder(resp.Body).Decode(obj)
}

// GetVolAnnotations gets annotations of volume
func GetVolAnnotations(volName string) (*Annotations, error) {
var volume Volume
var annotations Annotations
err := getVolDetails(volName, &volume)
if err != nil || volume.Metadata.Annotations == nil {
    if volume.Status.Reason == "pending" {
        fmt.Println("VSM status Unknown to server")
    }
    return nil, err
}
// Skipped some part,not required
}

I went through this blog and it exactly explains what my code requires but it uses Testing package and i want to implement this using ginkgo.

Take a loot at ghttp: http://onsi.github.io/gomega/#ghttp-testing-http-clients https://godoc.org/github.com/onsi/gomega/ghttp

A rough sketch might look like:

import (
    "os"

    . "github.com/onsi/ginkgo/tmp"
    "github.com/onsi/gomega/ghttp"

    . "github.com/onsi/ginkgo"
    . "github.com/onsi/gomega"
)

var _ = Describe("GetVolAnnotations", func() {
    var server *ghttp.Server
    var returnedVolume Volume
    var statusCode int

    BeforeEach(func() {
        server = ghttp.NewServer()
        os.Setenv("SOME_ADDR", server.Addr())

        server.AppendHandlers(
            ghttp.CombineHandlers(
                ghttp.VerifyRequest("GET", "/path/to/somepage/VOLUME"),
                ghttp.RespondWithJSONEncodedPtr(&statusCode, &returnedVolume),
            )
        )
    })

    AfterEach(func() {
        server.Close()
    })

    Context("When when the server returns a volume", func() {
        BeforeEach(func() {
            returnedVolume = Volume{
                Metadata: Metadata{
                    Annotations: []string{"foo"}
                }
            }
            statusCode = 200
        })

        It("returns the annotations associated with the volume", func() {
            Expect(GetVolAnnotations("VOLUME")).To(Equal([]string{"foo"}))
        })
    })

    Context("when the server returns 500", func() {
        BeforEach(func() {
            statusCode = 500
        })

        It("errors", func() {
            value, err := GetVolAnnotations("VOLUME")
            Expect(value).To(BeNil())
            Expect(err).To(HaveOccurred())
        })
    })

    Context("when the server returns 503", func() {
        BeforEach(func() {
            statusCode = 503
        })

        It("errors", func() {
            value, err := GetVolAnnotations("VOLUME")
            Expect(value).To(BeNil())
            Expect(err).To(HaveOccurred())
        })
    })
})

I think you've got a few issues with your code though. If you get a 500 or 503 status code you won't necessarily have an err so you'll need to create and send back a custom error.