Unit test the index handler

main.go

@@ -7,10 +7,12 @@ import (
 )
 
 func init() {
- http.HandleFunc("/", handler)
+ http.HandleFunc("/", IndexHandler)
 }
 
-func handler(w http.ResponseWriter, r *http.Request) {
+func IndexHandler(w http.ResponseWriter, r *http.Request) {
+ w.WriteHeader(http.StatusOK)
+ w.Header().Set("Content-Type", "text/plain")
  fmt.Fprint(w, "a plaintext pastebin service")
 }
 

main_test.go

@@ -1,6 +1,30 @@
 package main
 
-import "testing"
+import (
+ "testing"
+ "net/http"
+ "net/http/httptest"
+)
 
-func TestTrivial(t *testing.T) {
+func TestIndexHandler(t *testing.T) {
+ request, err := http.NewRequest("GET", "/", nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ response := httptest.NewRecorder()
+ http.HandlerFunc(IndexHandler).ServeHTTP(response, request)
+
+ if status := response.Code; status != http.StatusOK {
+ t.Errorf(
+ "Handler returned wrong status code: got %v want %v",
+ status, http.StatusOK)
+ }
+
+ expected_body := "a plaintext pastebin service"
+ if response.Body.String() != expected_body {
+ t.Errorf(
+ "Handler returned unexpected body: got %v want %v",
+ response.Body.String(), expected_body)
+ }
 }