Use standard error messages

bucket-view.go

@@ -32,8 +32,7 @@ func BucketViewHandler(s3 S3Client) http.Handler {
 
 		t, err := template.ParseFiles(l, p)
 		if err != nil {
-			msg := "error parsing templates"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 
@@ -42,14 +41,12 @@ func BucketViewHandler(s3 S3Client) http.Handler {
 		objectCh := s3.ListObjectsV2(bucketName, "", true, doneCh)
 		for object := range objectCh {
 			if object.Err != nil {
-				msg := "error listing objects"
 				code := http.StatusInternalServerError
-				if object.Err.Error() == "The specified bucket does not exist." {
+				if object.Err.Error() == ErrBucketDoesNotExist {
-					msg = "bucket not found"
 					code = http.StatusNotFound
 				}
 
-				handleHTTPError(w, msg, object.Err, code)
+				handleHTTPError(w, code, object.Err)
 				return
 			}
 			objectWithIcon := ObjectWithIcon{object, icon(object.Key)}
@@ -63,8 +60,7 @@ func BucketViewHandler(s3 S3Client) http.Handler {
 
 		err = t.ExecuteTemplate(w, "layout", bucketPage)
 		if err != nil {
-			msg := "error executing template"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 	})

bucket-view_test.go

@@ -88,7 +88,7 @@ func TestBucketViewHandler(t *testing.T) {
 			s3:                    &S3ClientMock{},
 			bucketName:            "testBucket",
 			expectedStatusCode:    http.StatusNotFound,
-			expectedBodyCountains: "bucket not found\n",
+			expectedBodyCountains: http.StatusText(http.StatusNotFound),
 		},
 		"s3 error": {
 			s3: &S3ClientMock{
@@ -96,7 +96,7 @@ func TestBucketViewHandler(t *testing.T) {
 			},
 			bucketName:            "testBucket",
 			expectedStatusCode:    http.StatusInternalServerError,
-			expectedBodyCountains: "error listing objects\n",
+			expectedBodyCountains: http.StatusText(http.StatusInternalServerError),
 		},
 	}
 

buckets-view.go

@@ -14,22 +14,19 @@ func BucketsViewHandler(s3 S3Client) http.Handler {
 
 		t, err := template.ParseFiles(l, p)
 		if err != nil {
-			msg := "error parsing templates"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 
 		buckets, err := s3.ListBuckets()
 		if err != nil {
-			msg := "error listing buckets"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 
 		err = t.ExecuteTemplate(w, "layout", buckets)
 		if err != nil {
-			msg := "error executing template"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 	})

buckets-view_test.go

@@ -37,7 +37,7 @@ func TestBucketsViewHandler(t *testing.T) {
 				Err: errors.New("mocked S3 error"),
 			},
 			expectedStatusCode:   http.StatusInternalServerError,
-			expectedBodyContains: "error listing buckets\n",
+			expectedBodyContains: http.StatusText(http.StatusInternalServerError),
 		},
 	}
 

create-bucket.go

@@ -14,15 +14,13 @@ func CreateBucketHandler(s3 S3Client) http.Handler {
 
 		err := json.NewDecoder(r.Body).Decode(&bucket)
 		if err != nil {
-			msg := "error decoding json"
+			handleHTTPError(w, http.StatusUnprocessableEntity, err)
-			handleHTTPError(w, msg, err, http.StatusUnprocessableEntity)
 			return
 		}
 
 		err = s3.MakeBucket(bucket.Name, "")
 		if err != nil {
-			msg := "error making bucket"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 
@@ -31,8 +29,7 @@ func CreateBucketHandler(s3 S3Client) http.Handler {
 
 		err = json.NewEncoder(w).Encode(bucket)
 		if err != nil {
-			msg := "error encoding json"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 	})

create-bucket_test.go

@@ -14,36 +14,36 @@ func TestCreateBucketHandler(t *testing.T) {
 	assert := assert.New(t)
 
 	tests := map[string]struct {
-		s3                 S3Client
+		s3                   S3Client
-		body               string
+		body                 string
-		expectedStatusCode int
+		expectedStatusCode   int
-		expectedBody       string
+		expectedBodyContains string
 	}{
 		"success": {
-			s3:                 &S3ClientMock{},
+			s3:                   &S3ClientMock{},
-			body:               "{\"name\":\"myBucket\"}",
+			body:                 "{\"name\":\"myBucket\"}",
-			expectedStatusCode: http.StatusCreated,
+			expectedStatusCode:   http.StatusCreated,
-			expectedBody:       "{\"name\":\"myBucket\",\"creationDate\":\"0001-01-01T00:00:00Z\"}\n",
+			expectedBodyContains: "{\"name\":\"myBucket\",\"creationDate\":\"0001-01-01T00:00:00Z\"}\n",
 		},
 		"empty request": {
-			s3:                 &S3ClientMock{},
+			s3:                   &S3ClientMock{},
-			body:               "",
+			body:                 "",
-			expectedStatusCode: http.StatusUnprocessableEntity,
+			expectedStatusCode:   http.StatusUnprocessableEntity,
-			expectedBody:       "error decoding json\n",
+			expectedBodyContains: http.StatusText(http.StatusUnprocessableEntity),
 		},
 		"malformed request": {
-			s3:                 &S3ClientMock{},
+			s3:                   &S3ClientMock{},
-			body:               "}",
+			body:                 "}",
-			expectedStatusCode: http.StatusUnprocessableEntity,
+			expectedStatusCode:   http.StatusUnprocessableEntity,
-			expectedBody:       "error decoding json\n",
+			expectedBodyContains: http.StatusText(http.StatusUnprocessableEntity),
 		},
 		"s3 error": {
 			s3: &S3ClientMock{
 				Err: errors.New("mocked S3 error"),
 			},
-			body:               "{\"name\":\"myBucket\"}",
+			body:                 "{\"name\":\"myBucket\"}",
-			expectedStatusCode: http.StatusInternalServerError,
+			expectedStatusCode:   http.StatusInternalServerError,
-			expectedBody:       "error making bucket\n",
+			expectedBodyContains: http.StatusText(http.StatusInternalServerError),
 		},
 	}
 
@@ -57,6 +57,6 @@ func TestCreateBucketHandler(t *testing.T) {
 		handler.ServeHTTP(rr, req)
 
 		assert.Equal(tc.expectedStatusCode, rr.Code, tcID)
-		assert.Equal(tc.expectedBody, rr.Body.String(), tcID)
+		assert.Contains(rr.Body.String(), tc.expectedBodyContains, tcID)
 	}
 }

create-object.go

@@ -28,8 +28,7 @@ func CreateObjectHandler(s3 S3Client) http.Handler {
 
 			err := json.NewDecoder(r.Body).Decode(&copy)
 			if err != nil {
-				msg := "error decoding json"
+				handleHTTPError(w, http.StatusInternalServerError, err)
-				handleHTTPError(w, msg, err, http.StatusUnprocessableEntity)
 				return
 			}
 
@@ -37,8 +36,7 @@ func CreateObjectHandler(s3 S3Client) http.Handler {
 			objectSource := fmt.Sprintf("/%s/%s", copy.SourceBucketName, copy.SourceObjectName)
 			err = s3.CopyObject(copy.BucketName, copy.ObjectName, objectSource, copyConds)
 			if err != nil {
-				msg := "error copying object"
+				handleHTTPError(w, http.StatusInternalServerError, err)
-				handleHTTPError(w, msg, err, http.StatusInternalServerError)
 				return
 			}
 
@@ -47,30 +45,26 @@ func CreateObjectHandler(s3 S3Client) http.Handler {
 
 			err = json.NewEncoder(w).Encode(copy)
 			if err != nil {
-				msg := "error encoding json"
+				handleHTTPError(w, http.StatusInternalServerError, err)
-				handleHTTPError(w, msg, err, http.StatusInternalServerError)
 				return
 			}
 		} else {
 			err := r.ParseMultipartForm(32 << 20)
 			if err != nil {
-				msg := "error parsing form"
+				handleHTTPError(w, http.StatusUnprocessableEntity, err)
-				handleHTTPError(w, msg, err, http.StatusUnprocessableEntity)
 				return
 			}
 
 			file, handler, err := r.FormFile("file")
 			if err != nil {
-				msg := "error getting form file"
+				handleHTTPError(w, http.StatusInternalServerError, err)
-				handleHTTPError(w, msg, err, http.StatusInternalServerError)
 				return
 			}
 			defer file.Close()
 
 			_, err = s3.PutObject(vars["bucketName"], handler.Filename, file, contentTypeOctetStream)
 			if err != nil {
-				msg := "error putting object"
+				handleHTTPError(w, http.StatusInternalServerError, err)
-				handleHTTPError(w, msg, err, http.StatusInternalServerError)
 				return
 			}
 

delete-bucket.go

@@ -13,8 +13,7 @@ func DeleteBucketHandler(s3 S3Client) http.Handler {
 
 		err := s3.RemoveBucket(vars["bucketName"])
 		if err != nil {
-			msg := "error removing bucket"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 

delete-bucket_test.go

@@ -13,21 +13,21 @@ func TestDeleteBucketHandler(t *testing.T) {
 	assert := assert.New(t)
 
 	tests := map[string]struct {
-		s3                 S3Client
+		s3                   S3Client
-		expectedStatusCode int
+		expectedStatusCode   int
-		expectedBody       string
+		expectedBodyContains string
 	}{
 		"success": {
-			s3:                 &S3ClientMock{},
+			s3:                   &S3ClientMock{},
-			expectedStatusCode: http.StatusNoContent,
+			expectedStatusCode:   http.StatusNoContent,
-			expectedBody:       "",
+			expectedBodyContains: "",
 		},
 		"s3 error": {
 			s3: &S3ClientMock{
 				Err: errors.New("mocked S3 error"),
 			},
-			expectedStatusCode: http.StatusInternalServerError,
+			expectedStatusCode:   http.StatusInternalServerError,
-			expectedBody:       "error removing bucket\n",
+			expectedBodyContains: http.StatusText(http.StatusInternalServerError),
 		},
 	}
 
@@ -41,6 +41,6 @@ func TestDeleteBucketHandler(t *testing.T) {
 		handler.ServeHTTP(rr, req)
 
 		assert.Equal(tc.expectedStatusCode, rr.Code, tcID)
-		assert.Equal(tc.expectedBody, rr.Body.String(), tcID)
+		assert.Contains(rr.Body.String(), tc.expectedBodyContains, tcID)
 	}
 }

delete-object.go

@@ -13,8 +13,7 @@ func DeleteObjectHandler(s3 S3Client) http.Handler {
 
 		err := s3.RemoveObject(vars["bucketName"], vars["objectName"])
 		if err != nil {
-			msg := "error removing object"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 

delete-object_test.go

@@ -13,21 +13,21 @@ func TestDeleteObjectHandler(t *testing.T) {
 	assert := assert.New(t)
 
 	tests := map[string]struct {
-		s3                 S3Client
+		s3                   S3Client
-		expectedStatusCode int
+		expectedStatusCode   int
-		expectedBody       string
+		expectedBodyContains string
 	}{
 		"success": {
-			s3:                 &S3ClientMock{},
+			s3:                   &S3ClientMock{},
-			expectedStatusCode: http.StatusNoContent,
+			expectedStatusCode:   http.StatusNoContent,
-			expectedBody:       "",
+			expectedBodyContains: "",
 		},
 		"s3 error": {
 			s3: &S3ClientMock{
 				Err: errors.New("mocked S3 error"),
 			},
-			expectedStatusCode: http.StatusInternalServerError,
+			expectedStatusCode:   http.StatusInternalServerError,
-			expectedBody:       "error removing object\n",
+			expectedBodyContains: http.StatusText(http.StatusInternalServerError),
 		},
 	}
 
@@ -41,6 +41,6 @@ func TestDeleteObjectHandler(t *testing.T) {
 		handler.ServeHTTP(rr, req)
 
 		assert.Equal(tc.expectedStatusCode, rr.Code, tcID)
-		assert.Equal(tc.expectedBody, rr.Body.String(), tcID)
+		assert.Contains(rr.Body.String(), tc.expectedBodyContains, tcID)
 	}
 }

errors.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"log"
+	"net/http"
+)
+
+// Common error messages within the app
+const (
+	ErrBucketDoesNotExist = "The specified bucket does not exist."
+	ErrKeyDoesNotExist    = "The specified key does not exist."
+)
+
+// handleHTTPError handles HTTP errors
+func handleHTTPError(w http.ResponseWriter, statusCode int, err error) {
+	msg := http.StatusText(statusCode)
+	http.Error(w, msg, statusCode)
+
+	logMsg := msg
+	if err != nil {
+		logMsg = logMsg + ": " + err.Error()
+	}
+	log.Println(logMsg)
+}

get-object.go

@@ -16,8 +16,7 @@ func GetObjectHandler(s3 S3Client) http.Handler {
 
 		object, err := s3.GetObject(vars["bucketName"], objectName)
 		if err != nil {
-			msg := "error getting object"
+			handleHTTPError(w, http.StatusInternalServerError, err)
-			handleHTTPError(w, msg, err, http.StatusInternalServerError)
 			return
 		}
 
@@ -26,18 +25,11 @@ func GetObjectHandler(s3 S3Client) http.Handler {
 
 		_, err = io.Copy(w, object)
 		if err != nil {
-			msg := "error copying object"
 			code := http.StatusInternalServerError
-			if err.Error() == "The specified key does not exist." {
+			if err.Error() == ErrBucketDoesNotExist || err.Error() == ErrKeyDoesNotExist {
-				msg = "object not found"
 				code = http.StatusNotFound
 			}
-			if err.Error() == "The specified bucket does not exist." {
+			handleHTTPError(w, code, err)
-				msg = "bucket not found"
-				code = http.StatusNotFound
-			}
-
-			handleHTTPError(w, msg, err, code)
 			return
 		}
 	})

get-object_test.go

@@ -29,7 +29,7 @@ func TestGetObjectHandler(t *testing.T) {
 			bucketName:            "testBucket",
 			objectName:            "testObject",
 			expectedStatusCode:    http.StatusInternalServerError,
-			expectedBodyCountains: "error getting object\n",
+			expectedBodyCountains: http.StatusText(http.StatusInternalServerError),
 		},
 	}
 

handle-http-error.go

@@ -1,16 +0,0 @@
-package main
-
-import (
-	"log"
-	"net/http"
-)
-
-// handleHTTPError handles HTTP errors
-func handleHTTPError(w http.ResponseWriter, msg string, err error, statusCode int) {
-	http.Error(w, msg, statusCode)
-	if err != nil {
-		log.Println(msg+":", err.Error())
-	} else {
-		log.Println(msg)
-	}
-}