Add linters that check for bugs (#310)

Author: lucacome

.golangci.yml

@@ -34,14 +34,19 @@ linters:
     - asasalint
     - asciicheck
     - bidichk
+    - contextcheck
     - dupword
+    - durationcheck
     - errcheck
+    - errchkjson
     - errname
     - errorlint
     - exportloopref
     - fatcontext
     - forcetypeassert
     - gocheckcompilerdirectives
+    - gochecksumtype
+    - gocritic
     - godot
     - gofmt
     - gofumpt
@@ -54,6 +59,7 @@ linters:
     - intrange
     - makezero
     - misspell
+    - musttag
     - nilerr
     - noctx
     - nolintlint

client/nginx.go

@@ -83,9 +83,9 @@ type StreamUpstreamServer struct {
 }
 
 type apiErrorResponse struct {
-	RequestID string `json:"request_id"`
-	Href      string
-	Error     apiError
+	RequestID string   `json:"request_id"`
+	Href      string   `json:"href"`
+	Error     apiError `json:"error"`
 }
 
 func (resp *apiErrorResponse) toString() string {
@@ -94,9 +94,9 @@ func (resp *apiErrorResponse) toString() string {
 }
 
 type apiError struct {
-	Text   string
-	Code   string
-	Status int
+	Text   string `json:"text"`
+	Code   string `json:"code"`
+	Status int    `json:"status"`
 }
 
 type internalError struct {

client/nginx_test.go

@@ -602,19 +602,20 @@ func TestClientWithHTTPClient(t *testing.T) {
 func TestGetStats_NoStreamEndpoint(t *testing.T) {
 	t.Parallel()
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.RequestURI == "/" {
+		switch {
+		case r.RequestURI == "/":
 			_, err := w.Write([]byte(`[4, 5, 6, 7, 8, 9]`))
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
 			}
-		} else if r.RequestURI == "/7/" {
+		case r.RequestURI == "/7/":
 			_, err := w.Write([]byte(`["nginx","processes","connections","slabs","http","resolvers","ssl"]`))
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
 			}
-		} else if strings.HasPrefix(r.RequestURI, "/7/stream") {
+		case strings.HasPrefix(r.RequestURI, "/7/stream"):
 			t.Fatal("Stream endpoint should not be called since it does not exist.")
-		} else {
+		default:
 			_, err := w.Write([]byte(`{}`))
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
@@ -654,17 +655,18 @@ func TestGetStats_NoStreamEndpoint(t *testing.T) {
 func TestGetStats_SSL(t *testing.T) {
 	t.Parallel()
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.RequestURI == "/" {
+		switch {
+		case r.RequestURI == "/":
 			_, err := w.Write([]byte(`[4, 5, 6, 7, 8, 9]`))
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
 			}
-		} else if r.RequestURI == "/8/" {
+		case r.RequestURI == "/8/":
 			_, err := w.Write([]byte(`["nginx","processes","connections","slabs","http","resolvers","ssl","workers"]`))
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
 			}
-		} else if strings.HasPrefix(r.RequestURI, "/8/ssl") {
+		case strings.HasPrefix(r.RequestURI, "/8/ssl"):
 			_, err := w.Write([]byte(`{
 				"handshakes" : 79572,
 				"handshakes_failed" : 21025,
@@ -684,7 +686,7 @@ func TestGetStats_SSL(t *testing.T) {
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
 			}
-		} else {
+		default:
 			_, err := w.Write([]byte(`{}`))
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)