refactor code in context_test.go

context/context_test.go

@@ -11,6 +11,7 @@ import (
 type SpyStore struct {
 	response  string
 	cancelled bool
+	t         *testing.T
 }
 
 func (s *SpyStore) Fetch() string {
@@ -22,30 +23,25 @@ func (s *SpyStore) Cancel() {
 	s.cancelled = true
 }
 
-func TestServer(t *testing.T) {
-	t.Run("tells store to cancel work if request is cancelled", func(t *testing.T) {
-		data := "hello, world"
-		store := &SpyStore{response: data}
-		svr := Server(store)
-
-		request := httptest.NewRequest(http.MethodGet, "/", nil)
-
-		cancellingCtx, cancel := context.WithCancel(request.Context())
-		time.AfterFunc(5*time.Millisecond, cancel)
-		request = request.WithContext(cancellingCtx)
-
-		response := httptest.NewRecorder()
+func (s *SpyStore) assertWasCancelled() {
+	s.t.Helper()
 
-		svr.ServeHTTP(response, request)
+	if !s.cancelled {
+		s.t.Error("store was not told to cancel")
+	}
+}
 
-		if !store.cancelled {
-			t.Error("store was not told to cancel")
-		}
-	})
+func (s *SpyStore) assertWasNotCancelled() {
+	s.t.Helper()
+	if s.cancelled {
+		s.t.Error("store was told to cancel")
+	}
+}
 
+func TestServer(t *testing.T) {
 	t.Run("returns data from store", func(t *testing.T) {
 		data := "hello, world"
-		store := &SpyStore{response: data}
+		store := &SpyStore{response: data, t: t}
 		srv := Server(store)
 
 		request := httptest.NewRequest(http.MethodGet, "/", nil)
@@ -57,8 +53,24 @@ func TestServer(t *testing.T) {
 			t.Errorf("got %v, want %v", response.Body.String(), data)
 		}
 
-		if store.cancelled {
-			t.Errorf("it should not have cancelled the store")
-		}
+		store.assertWasNotCancelled()
+	})
+
+	t.Run("tells store to cancel work if request is cancelled", func(t *testing.T) {
+		data := "hello, world"
+		store := &SpyStore{response: data, t: t}
+		svr := Server(store)
+
+		request := httptest.NewRequest(http.MethodGet, "/", nil)
+
+		cancellingCtx, cancel := context.WithCancel(request.Context())
+		time.AfterFunc(5*time.Millisecond, cancel)
+		request = request.WithContext(cancellingCtx)
+
+		response := httptest.NewRecorder()
+
+		svr.ServeHTTP(response, request)
+
+		store.assertWasCancelled()
 	})
 }