I am trying to mock an HTTP client that's being used within an API function call in my Go code.
import (
"internal.repo/[...]/http"
"encoding/json"
"strings"
"github.com/stretchr/testify/require"
)
func CreateResource(t *testing.T, url string, bodyReq interface{}, username string, password string, resource string) []byte {
bodyReqJSON, err := json.Marshal(bodyReq)
if err != nil {
panic(err)
}
headers := make(map[string]string)
headers["Content-Type"] = "application/json"
logger.Logf(t, "*************************** CREATE a temporary test %s ***************************", resource)
// this func below should be mocked
statusCode, body := http.POST(t, url, bodyReqJSON, headers, username, password)
require.Equal(t, statusCode, 201, "******ERROR!! A problem occurred while creating %s. Body: %s******", resource, strings.TrimSpace(string(body)))
return body
}
I'd like to mock my http.POST function that it's part of an internal HTTP package so that I do not need to actually make the online call, and isolate the test offline.
Is there an alternative way to dependency-inject a mock structure that implements an hypothetical HTTP interface?
How would you do something like this?
Here's the solution, thanks to #Peter.
import (
"net/http"
"net/http/httptest"
"testing"
"github.com/stretchr/testify/assert"
)
func TestCreateResource(t *testing.T) {
t.Run("successful", func(t *testing.T) {
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(201)
}))
defer server.Close()
o := CreateResource(t, server.URL, nil, "admin", "password", "resource")
assert.Equal(t, []byte{}, o)
})
}
Related
I've looked into various different tools that can be used for mock testing in golang, but I'm trying to accomplish this task using httptest. In particular, I have a function as such:
type contact struct {
username string
number int
}
func getResponse(c contact) string {
url := fmt.Sprintf("https://mywebsite/%s", c.username)
req, err := http.NewRequest(http.MethodGet, url, nil)
// error checking
resp, err := http.DefaultClient.Do(req)
// error checking
return response
}
A lot of the documentation I've read seems to require creating a client interface or a custom transport. Is there no way to mock a response in a test file without changing this main code at all? I want to keep my client, response, and all the related details within the getResponse function. I could have the wrong idea, but I'm trying to find a way to intercept the http.DefaultClient.Do(req) call and return a custom response, is that possible?
https://pkg.go.dev/net/http/httptest#example-Server is a good example for your use case with a small refactoring of your code.
You just have to change the getResponse() by getResponse(url string) to be able to give the server mock url.
I've read seems to require creating a client interface
without changing this main code at all
Keeping your code clean is a good practice and you'll finally get used to it, a testable code is cleaner and a cleaner code is more testable, so don't worry to change your code (using interfaces) so it can accept mock objects.
Your code in its simplest form can be like this:
package main
import (
"fmt"
"net/http"
)
type contact struct {
username string
number int
}
type Client interface {
Do(req *http.Request) (*http.Response, error)
}
func main() {
getResponse(http.DefaultClient, contact{})
}
func getResponse(client Client, c contact) string {
url := fmt.Sprintf("https://mywebsite/%s", c.username)
req, _ := http.NewRequest(http.MethodGet, url, nil)
// error checking
resp, _ := http.DefaultClient.Do(req)
// error checking and response processing
return response
}
And your test can be like this:
package main
import (
"net/http"
"testing"
)
type mockClient struct {
}
// Do function will cause mockClient to implement the Client interface
func (tc mockClient) Do(req *http.Request) (*http.Response, error) {
return &http.Response{}, nil
}
func TestGetResponse(t *testing.T) {
client := new(mockClient)
getResponse(client, contact{})
}
But if you prefer to use httptest:
package main
import (
"fmt"
"io"
"net/http"
"net/http/httptest"
)
type contact struct {
username string
number int
}
func main() {
fmt.Println(getResponse(contact{}))
}
func getResponse(c contact) string {
// Make a test server
ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
fmt.Fprintln(w, "your response")
}))
defer ts.Close()
// You should still set your base url
base_url := ts.URL
url := fmt.Sprintf("%s/%s", base_url, c.username)
req, _ := http.NewRequest(http.MethodGet, url, nil)
// Use ts.Client() instead of http.DefaultClient in your tests.
resp, _ := ts.Client().Do(req)
// Processing the response
response, _ := io.ReadAll(resp.Body)
resp.Body.Close()
return string(response)
}
How do I get the body that was sent?
package main
import (
"fmt"
"github.com/gin-gonic/gin"
)
func main() {
fmt.Println("Hello, world!")
r := gin.Default()
r.POST("/", func(c *gin.Context) {
body := c.Request.Body
c.JSON(200,body);
})
r.Run(":8080");
}
I make a request via postman
{
"email": "test#gmail.com",
"password": "test"
}
and in response I get empty json {}
what to do?
You can bind the incoming request json as follows:
package main
import (
"github.com/gin-gonic/gin"
)
type LoginReq struct {
Email string
Password string
}
func main() {
r := gin.Default()
r.POST("/", func(c *gin.Context) {
var req LoginReq
c.BindJSON(&req)
c.JSON(200, req)
})
r.Run(":8080")
}
Remember this method gives 400 if there is a binding error. If you want to handle error yourself, try ShouldBindJSON which returns an error if any or nil.
I've some web-application server using go http and I want that each request will have context with uuid, for this I can use http request context https://golang.org/pkg/net/http/#Request.Context
we are using logrus and we initiate it in one file and use the logger instance in other files.
what I need is to print request ID in all the logs but not to add new paremeters to each log print, I want do to it once in each http request (pass the req-id) and all the logs print will have it without doing anything with it
e.g. if the id=123 so log.info("foo") will print
// id=123 foo
I've tried with the following but not sure it's the right way, please advice.
package main
import (
"context"
"errors"
log "github.com/sirupsen/logrus"
)
type someContextKey string
var (
keyA = someContextKey("a")
keyB = someContextKey("b")
)
func main() {
ctx := context.Background()
ctx = context.WithValue(ctx, keyA, "foo")
ctx = context.WithValue(ctx, keyB, "bar")
logger(ctx, nil).Info("did nothing")
err := errors.New("an error")
logger(ctx, err).Fatal("unrecoverable error")
}
func logger(ctx context.Context, err error) *log.Entry {
entry := log.WithField("component", "main")
entry = entry.WithField("ReqID", "myRequestID")
return entry
}
https://play.golang.org/p/oCW09UhTjZ5
Every time you call the logger function you are creating a new *log.Entry and writing the request ID to it again. From your question it sounded like you do not want that.
func main() {
ctx := context.Background()
ctx = context.WithValue(ctx, keyA, "foo")
ctx = context.WithValue(ctx, keyB, "bar")
lg := logger(ctx)
lg.Info("did nothing")
err := errors.New("an error")
lg.WithError(err).Fatal("unrecoverable error")
}
func logger(ctx context.Context) *log.Entry {
entry := log.WithField("component", "main")
entry = entry.WithField("ReqID", "myRequestID")
return entry
}
The downside of this is that you will have to pass the lg variable to every function this request calls and which should also log the request ID.
What we did at our company is create a thin layer around logrus that has an additional method WithRequestCtx so we could pass in the request context and it would extract the request ID itself (which we had written to the context in a middleware). If no request ID was present nothing was added to the log entry. This however did add the request ID to every log entry again as your sample code also did.
Note: our thin layer around logrus had a lot more functionality and default settings to justify the extra effort. In the long run this turned out very helpful to have one place to be able to adjust logging for all our services.
Note2: meanwhile we are in the process of replacing logrus with zerolog to be more lightweight.
Late answer but all you need to do is just call logrus.WithContext(/* your *http.Request.Context() goes here*/).... in your application and logrus will automatically add "id":"SOME-UUID" to each logs. Design is flexible for extracting more key-value from request context if you wanted to.
initialise logger
package main
import (
"path/to/logger"
"path/to/request"
)
func main() {
err := logger.Setup(logger.Config{
ContextFields: map[string]interface{}{
string(request.CtxIDKey): request.CtxIDKey,
}
})
if err != nil {
// ...
}
}
logger
package logger
import (
"github.com/sirupsen/logrus"
)
type Config struct {
Level string
ContextFields map[string]interface{}
}
func Setup(config Config) error {
lev, err := logrus.ParseLevel(config.Level)
if err != nil {
return err
}
logrus.SetLevel(lev)
return nil
}
func (c Config) Fire(e *logrus.Entry) error {
for k, v := range c.StaticFields {
e.Data[k] = v
}
if e.Context != nil {
for k, v := range c.ContextFields {
if e.Context.Value(v) != nil {
e.Data[k] = e.Context.Value(v).(string)
}
}
}
return nil
}
request
package request
import (
"context"
"net/http"
"github.com/google/uuid"
)
type ctxID string
const CtxIDKey = ctxID("id")
func ID(h http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
h.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), CtxIDKey, uuid.New().String())))
})
}
I'm having difficulty authenticating using Google OAuth2.
I've obtainedd client ID and secret from google developer console, and I came up with this code :
package main
import (
"fmt"
"golang.org/x/oauth2"
"golang.org/x/oauth2/google"
"io/ioutil"
"net/http"
"os"
)
const htmlIndex = `<html><body>
Log in with Google
</body></html>
`
func init() {
// Setup Google's example test keys
os.Setenv("CLIENT_ID", "somrestring-otherstring.apps.googleusercontent.com")
os.Setenv("SECRET_KEY", "alongcharachterjumble")
}
var (
googleOauthConfig = &oauth2.Config{
RedirectURL: "http://127.0.0.1:8080/auth", //defined in Google console
ClientID: os.Getenv("CLIENT_ID"),
ClientSecret: os.Getenv("SECRET_KEY"),
Scopes: []string{"https://www.googleapis.com/auth/userinfo.profile",
"https://www.googleapis.com/auth/userinfo.email"},
Endpoint: google.Endpoint,
}
// Some random string, random for each request
oauthStateString = "random"
)
func main() {
http.HandleFunc("/", handleMain)
http.HandleFunc("/GoogleLogin", handleGoogleLogin)
http.HandleFunc("/GoogleCallback", handleGoogleCallback)
fmt.Println(http.ListenAndServe(":8080", nil))
}
func handleMain(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, htmlIndex)
fmt.Println("another request made")
}
func handleGoogleLogin(w http.ResponseWriter, r *http.Request) {
url := googleOauthConfig.AuthCodeURL(oauthStateString)
http.Redirect(w, r, url, http.StatusTemporaryRedirect)
}
func handleGoogleCallback(w http.ResponseWriter, r *http.Request) {
state := r.FormValue("state")
if state != oauthStateString {
fmt.Printf("invalid oauth state, expected '%s', got '%s'\n", oauthStateString, state)
http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
return
}
code := r.FormValue("code")
token, err := googleOauthConfig.Exchange(oauth2.NoContext, code)
if err != nil {
fmt.Println("Code exchange failed with '%s'\n", err)
http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
return
}
response, err := http.Get("https://www.googleapis.com/oauth2/v2/userinfo?access_token=" + token.AccessToken)
defer response.Body.Close()
contents, err := ioutil.ReadAll(response.Body)
fmt.Fprintf(w, "Content: %s\n", contents)
}
But I get this error from google:
That’s an error.
Error: invalid_request
Missing required parameter: client_id
Learn more
Request Details client_id= redirect_uri=http://127.0.0.1:8080/auth
response_type=code
scope=https://www.googleapis.com/auth/userinfo.profile
https://www.googleapis.com/auth/userinfo.email state=random
What's wrong here? How can I fix it?
The error message indicates that ClientID is not initialized.
That looks consistent with the code, since var declarations are executed before the init functions.
So when your var requests os.Getenv("CLIENT_ID") the value is blank since init has not executed yet.
From the documentation:
A package with no imports is initialized by assigning initial values to all its package-level variables followed by calling all init functions in the order they appear in the source, possibly in multiple files, as presented to the compiler
https://golang.org/ref/spec#Package_initialization
To fix this, either put the string directly in the var initialization, or trigger the initialization from the init after you set the values.
Like:
var (
googleOauthConfig *oauth2.Config
)
func init() {
// init ENV
// initialize the variable using ENV values
googleOauthConfig = &oauth2.Config{ ... }
}
Alternatively, you can set those ENV values at the OS level before executing the actual Go program.
I wrote a functions that save data into redis database server. The challenge is that I want to test these functions and do not know how to test it.
I just start somehow with
Functions
package sessrage
/*
* Save data into redis database. In the common case,
* the data will be only valid during a request. Use
* hash datatype in redis.
*/
import (
"../context"
"github.com/garyburd/redigo/redis"
"net/http"
)
const (
protocol string = "tcp"
port string = ":6379"
)
func connectAndCloseRedis(connectCall func(con redis.Conn)) {
c, err := redis.Dial("tcp", ":6379")
defer c.Close()
if err != nil {
panic(err.Error())
}
connectCall(c)
}
func PostSessionData(r *http.Request, key, value string) {
go connectAndCloseRedis(func(con redis.Conn) {
sessionId := context.Get(r, context.JwtId).(string)
con.Do("HMSET", sessionId, key, value)
})
}
func GetSessionData(r *http.Request, key string) interface{} {
var result interface{}
sessionId := context.Get(r, context.JwtId).(string)
reply, _ := redis.Values(c.Do("HMGET", sessionId, key))
redis.Scan(reply, &result)
return result
}
and the test file
package sessrage
import (
//"fmt"
"../context"
. "github.com/smartystreets/goconvey/convey"
"github.com/stretchr/testify/assert"
"net/http"
"net/http/httptest"
"testing"
"time"
)
var server *httptest.Server
var glrw http.ResponseWriter
var glr *http.Request
func init() {
server = httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
glrw = rw
glr = r
context.Set(glr, context.JwtId, "TestId")
}))
}
func TestPostAndGetSession(t *testing.T) {
Convey("POST and GET data on redis.", t, func() {
PostSessionData(glr, "key1", "value1")
time.Sleep(time.Second * 10)
v := GetSessionData(glr, "key1")
assert.Equal(t, "value1", v)
})
}
when I try to run the test I've got
an't load package: ......./sessrage.go:10:2: local import "../context" in non-local package
and the context package looks like
package context
import (
"github.com/gorilla/context"
"net/http"
)
type contextKey int
const (
LanguageId contextKey = iota
JwtId
)
func Get(r *http.Request, key interface{}) interface{} {
return context.Get(r, key)
}
func Set(r *http.Request, key, val interface{}) {
context.Set(r, key, val)
}
What do I wrong?
That is the first time, I am testing code in conjunction with http. It seems to be very hard to test.
There are a few issues:
Don't use relative import paths.
Use a pool instead of dialing redis on every action.
The call to sessionId := context.Get(r, context.JwtId).(string) in the PostSessionData anonymous function can fail if the mux or something higher in the call chain clears the Gorilla context before the goroutine runs. Do this instead:
func PostSessionData(r *http.Request, key, value string) {
c := pool.Get()
defer c.Close()
sessionId := context.Get(r, context.JwtId).(string)
if err := c.Do("HMSET", sessionId, key, value); err != nil {
// handle error
}
}