From 5204192574fa16befb09956a2bedfa61a7225098 Mon Sep 17 00:00:00 2001
From: Florent Biville <florent.biville@neo4j.com>
Date: Tue, 7 Mar 2023 19:04:44 +0100
Subject: [PATCH] Refine error message, add test case

---
 modulegen/main.go      |  4 ++--
 modulegen/main_test.go | 20 ++++++++++++++++++--
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/modulegen/main.go b/modulegen/main.go
index 91c312c11d2..d5e6b8b4edb 100644
--- a/modulegen/main.go
+++ b/modulegen/main.go
@@ -97,11 +97,11 @@ func (e *Example) Type() string {
 
 func (e *Example) Validate() error {
 	if !regexp.MustCompile(`^[A-Za-z][A-Za-z0-9]*$`).MatchString(e.Name) {
-		return fmt.Errorf("invalid name: %s. Only alphanumerical characters are allowed", e.Name)
+		return fmt.Errorf("invalid name: %s. Only alphanumerical characters are allowed (leading character must be a letter)", e.Name)
 	}
 
 	if !regexp.MustCompile(`^[A-Za-z][A-Za-z0-9]*$`).MatchString(e.TitleName) {
-		return fmt.Errorf("invalid title: %s. Only alphanumerical characters are allowed", e.TitleName)
+		return fmt.Errorf("invalid title: %s. Only alphanumerical characters are allowed (leading character must be a letter)", e.TitleName)
 	}
 
 	return nil
diff --git a/modulegen/main_test.go b/modulegen/main_test.go
index 2e985dfccd2..c29463062f3 100644
--- a/modulegen/main_test.go
+++ b/modulegen/main_test.go
@@ -113,7 +113,7 @@ func TestExample_Validate(outer *testing.T) {
 				Name:      "Amazing DB 4 The Win",
 				TitleName: "AmazingDB",
 			},
-			expectedErr: errors.New("invalid name: Amazing DB 4 The Win. Only alphanumerical characters are allowed"),
+			expectedErr: errors.New("invalid name: Amazing DB 4 The Win. Only alphanumerical characters are allowed (leading character must be a letter)"),
 		},
 		{
 			name: "non-alphanumerical characters in title",
@@ -121,7 +121,23 @@ func TestExample_Validate(outer *testing.T) {
 				Name:      "AmazingDB",
 				TitleName: "Amazing DB 4 The Win",
 			},
-			expectedErr: errors.New("invalid title: Amazing DB 4 The Win. Only alphanumerical characters are allowed"),
+			expectedErr: errors.New("invalid title: Amazing DB 4 The Win. Only alphanumerical characters are allowed (leading character must be a letter)"),
+		},
+		{
+			name: "leading numerical character in name",
+			example: Example{
+				Name:      "1AmazingDB",
+				TitleName: "AmazingDB",
+			},
+			expectedErr: errors.New("invalid name: 1AmazingDB. Only alphanumerical characters are allowed (leading character must be a letter)"),
+		},
+		{
+			name: "leading numerical character in title",
+			example: Example{
+				Name:      "AmazingDB",
+				TitleName: "1AmazingDB",
+			},
+			expectedErr: errors.New("invalid title: 1AmazingDB. Only alphanumerical characters are allowed (leading character must be a letter)"),
 		},
 	}