Fixed golangci-lint reported linting issues

Signed-off-by: Frederic BIDON <fredbi@yahoo.com>

.golangci.yml

@@ -0,0 +1,19 @@
+linters-settings:
+  govet:
+    check-shadowing: true
+  golint:
+    min-confidence: 0
+  gocyclo:
+    min-complexity: 30
+  maligned:
+    suggest-new: true
+  dupl:
+    threshold: 100
+  goconst:
+    min-len: 2
+    min-occurrences: 4
+linters:
+  enable-all: true
+  disable:
+    - maligned
+    - lll

api.go

@@ -134,26 +134,26 @@ func ServeError(rw http.ResponseWriter, r *http.Request, err error) {
 		rw.Header().Add("Allow", strings.Join(err.(*MethodNotAllowedError).Allowed, ","))
 		rw.WriteHeader(asHTTPCode(int(e.Code())))
 		if r == nil || r.Method != head {
-			rw.Write(errorAsJSON(e))
+			_, _ = rw.Write(errorAsJSON(e))
 		}
 	case Error:
 		value := reflect.ValueOf(e)
 		if value.Kind() == reflect.Ptr && value.IsNil() {
 			rw.WriteHeader(http.StatusInternalServerError)
-			rw.Write(errorAsJSON(New(http.StatusInternalServerError, "Unknown error")))
+			_, _ = rw.Write(errorAsJSON(New(http.StatusInternalServerError, "Unknown error")))
 			return
 		}
 		rw.WriteHeader(asHTTPCode(int(e.Code())))
 		if r == nil || r.Method != head {
-			rw.Write(errorAsJSON(e))
+			_, _ = rw.Write(errorAsJSON(e))
 		}
 	case nil:
 		rw.WriteHeader(http.StatusInternalServerError)
-		rw.Write(errorAsJSON(New(http.StatusInternalServerError, "Unknown error")))
+		_, _ = rw.Write(errorAsJSON(New(http.StatusInternalServerError, "Unknown error")))
 	default:
 		rw.WriteHeader(http.StatusInternalServerError)
 		if r == nil || r.Method != head {
-			rw.Write(errorAsJSON(New(http.StatusInternalServerError, err.Error())))
+			_, _ = rw.Write(errorAsJSON(New(http.StatusInternalServerError, err.Error())))
 		}
 	}
 }

headers.go

@@ -54,7 +54,7 @@ const (
 
 // InvalidContentType error for an invalid content type
 func InvalidContentType(value string, allowed []string) *Validation {
-	var values []interface{}
+	values := make([]interface{}, 0, len(allowed))
 	for _, v := range allowed {
 		values = append(values, v)
 	}
@@ -70,7 +70,7 @@ func InvalidContentType(value string, allowed []string) *Validation {
 
 // InvalidResponseFormat error for an unacceptable response format request
 func InvalidResponseFormat(value string, allowed []string) *Validation {
-	var values []interface{}
+	values := make([]interface{}, 0, len(allowed))
 	for _, v := range allowed {
 		values = append(values, v)
 	}

schema_test.go

@@ -293,10 +293,10 @@ func TestSchemaErrors(t *testing.T) {
 	assert.EqualValues(t, CompositeErrorCode, err2.Code())
 	assert.Equal(t, "validation failure list", err2.Error())
 
-	err2 = CompositeValidationError(fmt.Errorf("First error"), fmt.Errorf("Second error"))
+	err2 = CompositeValidationError(fmt.Errorf("first error"), fmt.Errorf("second error"))
 	assert.Error(t, err2)
 	assert.EqualValues(t, CompositeErrorCode, err2.Code())
-	assert.Equal(t, "validation failure list:\nFirst error\nSecond error", err2.Error())
+	assert.Equal(t, "validation failure list:\nfirst error\nsecond error", err2.Error())
 
 	//func MultipleOfMustBePositive(name, in string, factor interface{}) *Validation {
 	err = MultipleOfMustBePositive("path", "body", float64(-10))