How to do unit testing of HTTP requests using Ginkgo?

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\n", 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 look at ghttp package:
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 from your server.