cyrtophora

commit 1260f427514333d961218b7f82b80803c70f0d76
parent 9b3451ca36d0ffcdb9731e552cc49d74e2fee8c4
Author: Jackson G. Kaindume <seestem@merely.tech>
Date:   Sun, 21 Aug 2022 11:33:39 +0200

add input validator

Diffstat:
A
src/validator.rs
 | 
77
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 77 insertions(+), 0 deletions(-)
diff --git a/src/validator.rs b/src/validator.rs
@@ -0,0 +1,77 @@
+pub struct Validator;
+
+impl Validator {
+    /// Validate username (using Twitter style usernames)
+    pub fn username(username: &str) -> bool {
+        // Username cannot be empty
+        if username.is_empty() {
+            return false;
+        }
+
+        // Username length cannot be greater than 15 characters
+        if username.len() > 15 {
+            return false;
+        }
+
+        let chars: Vec<char> = username.chars().collect();
+        let mut underscore_count = 0;
+
+        for i in 0..chars.len() {
+            // Username cannot start with a underscore (_)
+            if i == 0 && chars[i] == '_' {
+                return false;
+            }
+
+            // Username can only contain letters, numbers, and one underscore
+            if chars[i] != '_' {
+                if !chars[i].is_ascii_alphanumeric() {
+                    return false;
+                }
+            } else {
+                // Count underscores because username can have only one [ _ ] underscore
+                underscore_count += 1;
+            }
+        }
+
+        // Username can have only one [ _ ] underscore
+        if underscore_count > 1 {
+            return false;
+        }
+
+        true
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn username_validation() {
+        let valid_username = "firephoenix";
+        let valid_username1 = "natty_dread";
+        let valid_username2 = "ironlion_ironii";
+        let invalid_username = "";
+        let invalid_username1 = "natty_dread_iron";
+        let invalid_username2 = "_natty_dread_iron";
+        let invalid_username3 = "nattydre@d";
+        let invalid_username4 = "nattydread$";
+        let invalid_username5 = "firephoenixfirephoenixfirephoenixfirephoenixfirephoenix";
+
+        assert!(Validator::username(valid_username));
+        assert!(Validator::username(valid_username1));
+        assert!(Validator::username(valid_username2));
+
+        // username cannot be empty
+        assert!(!Validator::username(invalid_username));
+        // username cannot contain more than 1 underscore
+        assert!(!Validator::username(invalid_username1));
+        // username cannot start with an underscore
+        assert!(!Validator::username(invalid_username2));
+        // username cannot contain special symbols (only the _ is allowed)
+        assert!(!Validator::username(invalid_username3));
+        assert!(!Validator::username(invalid_username4));
+        // username cannot be more than 15 characters long
+        assert!(!Validator::username(invalid_username5));
+    }
+}