improving code coverage

app/http/http.go

@@ -43,8 +43,10 @@ func FindAuthorizedContentType(h http.Header) (ContentType, error) {
 
 type notAuthorizedFileContentTypeError struct{}
 
+const notAuthorizedFileContentTypeErrorMessage = "Unable to detect an authorized file content type"
+
 func (e *notAuthorizedFileContentTypeError) Error() string {
-	return fmt.Sprintf("Unable to detect a file content type")
+	return notAuthorizedFileContentTypeErrorMessage
 }
 
 // SniffContentType tries to detect the content type of a file.

app/http/http_test.go

@@ -1,6 +1,7 @@
 package http
 
 import (
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -40,3 +41,18 @@ func TestSniffContentType(t *testing.T) {
 		t.Error("It should have been able to retrieve an authorized content type from a PDF file!")
 	}
 }
+
+func TestNotAuthorizedContentTypeError(t *testing.T) {
+	err := &notAuthorizedContentTypeError{}
+	message := fmt.Sprintf("Accepted values for 'Content-Type': %s, %s", OctetStreamContentType, MultipartFormDataContentType)
+	if err.Error() != message {
+		t.Errorf("Error returned a wrong message: got %s want %s", err.Error(), message)
+	}
+}
+
+func TestNotAuthorizedFileContentTypeError(t *testing.T) {
+	err := &notAuthorizedFileContentTypeError{}
+	if err.Error() != notAuthorizedFileContentTypeErrorMessage {
+		t.Errorf("Error returned a wrong message: got %s want %s", err.Error(), notAuthorizedFileContentTypeErrorMessage)
+	}
+}