Improve username validation

src/models/profiles/validators.rs

@@ -1,10 +1,20 @@
+use regex::Regex;
 use crate::errors::ValidationError;
 use crate::utils::html::{clean_html, clean_html_strict};
 
+const USERNAME_RE: &str = r"^[a-zA-Z0-9_\.-]+$";
+
 pub fn validate_username(username: &str) -> Result<(), ValidationError> {
+    if username.is_empty() {
+        return Err(ValidationError("username is empty"));
+    };
     if username.len() > 100 {
         return Err(ValidationError("username is too long"));
     };
+    let username_regexp = Regex::new(USERNAME_RE).unwrap();
+    if !username_regexp.is_match(username) {
+        return Err(ValidationError("invalid username"));
+    };
     Ok(())
 }
 
@@ -41,8 +51,18 @@ mod tests {
     fn test_validate_username() {
         let result_1 = validate_username("test");
         assert!(result_1.is_ok());
-        let result_2 = validate_username(&"x".repeat(101));
+        let result_2 = validate_username("test_12-3.xyz");
-        assert!(result_2.is_err());
+        assert!(result_2.is_ok());
+    }
+
+    #[test]
+    fn test_validate_username_error() {
+        let error = validate_username(&"x".repeat(101)).unwrap_err();
+        assert_eq!(error.to_string(), "username is too long");
+        let error = validate_username("").unwrap_err();
+        assert_eq!(error.to_string(), "username is empty");
+        let error = validate_username("abc&").unwrap_err();
+        assert_eq!(error.to_string(), "invalid username");
     }
 
     #[test]