fix(core): encode postgres usernames in connection urls (#40)

Encode saved Postgres usernames when building runtime connection URLs
and decode usernames imported from pasted URLs. This keeps `@` from
breaking URI parsing while preserving literal percent sequences.

Author: fcoury

crates/tsql/src/config/connections.rs

@@ -416,7 +416,7 @@ impl ConnectionEntry {
         let mut url = "postgres://".to_string();
 
         // Add user
-        url.push_str(&self.user);
+        url.push_str(&urlencoding::encode(&self.user));
 
         // Add password if provided
         if let Some(pwd) = password {
@@ -528,7 +528,9 @@ impl ConnectionEntry {
                 DbKind::Mongo => String::new(),
             }
         } else {
-            url.username().to_string()
+            urlencoding::decode(url.username())
+                .map(|s| s.into_owned())
+                .unwrap_or_else(|_| url.username().to_string())
         };
 
         let password = url.password().map(|p| {
@@ -2088,6 +2090,51 @@ user = "me"
         assert!(url.contains("p%40ss%3Aword%2F123"));
     }
 
+    #[test]
+    fn test_connection_to_url_with_at_in_username() {
+        let entry = ConnectionEntry {
+            name: "test".to_string(),
+            host: "localhost".to_string(),
+            port: 5432,
+            database: "mydb".to_string(),
+            user: "user@domain.com".to_string(),
+            ..Default::default()
+        };
+
+        let url = entry.to_url(None);
+        assert_eq!(url, "postgres://user%40domain.com@localhost/mydb");
+    }
+
+    #[test]
+    fn test_connection_to_url_encodes_reserved_username_chars() {
+        let entry = ConnectionEntry {
+            name: "test".to_string(),
+            host: "localhost".to_string(),
+            port: 5432,
+            database: "mydb".to_string(),
+            user: "user:name/role".to_string(),
+            ..Default::default()
+        };
+
+        let url = entry.to_url(None);
+        assert_eq!(url, "postgres://user%3Aname%2Frole@localhost/mydb");
+    }
+
+    #[test]
+    fn test_connection_to_url_preserves_literal_percent_username() {
+        let entry = ConnectionEntry {
+            name: "test".to_string(),
+            host: "localhost".to_string(),
+            port: 5432,
+            database: "mydb".to_string(),
+            user: "user%40team".to_string(),
+            ..Default::default()
+        };
+
+        let url = entry.to_url(None);
+        assert_eq!(url, "postgres://user%2540team@localhost/mydb");
+    }
+
     #[test]
     fn test_connection_to_url_non_default_port() {
         let entry = ConnectionEntry {
@@ -2117,6 +2164,28 @@ user = "me"
         assert!(entry.ssl_mode.is_none());
     }
 
+    #[test]
+    fn test_connection_from_url_decodes_encoded_username() {
+        let (entry, password) =
+            ConnectionEntry::from_url("test", "postgres://user%40domain.com@localhost/mydb")
+                .unwrap();
+
+        assert_eq!(entry.user, "user@domain.com");
+        assert!(password.is_none());
+    }
+
+    #[test]
+    fn test_connection_url_round_trip_literal_percent_username() {
+        let (entry, password) =
+            ConnectionEntry::from_url("test", "postgres://user%2540team@localhost/mydb").unwrap();
+
+        assert_eq!(entry.user, "user%40team");
+        assert!(password.is_none());
+
+        let url = entry.to_url(None);
+        assert_eq!(url, "postgres://user%2540team@localhost/mydb");
+    }
+
     #[test]
     fn test_connection_from_url_with_password() {
         let (entry, password) =

crates/tsql/src/ui/connection_form.rs

@@ -2133,6 +2133,21 @@ mod tests {
         assert!(form.url_paste.is_empty());
     }
 
+    #[test]
+    fn test_url_paste_decodes_postgres_username() {
+        let mut form = ConnectionFormModal::new();
+        form.focused = FormField::UrlPaste;
+        form.url_paste =
+            "postgres://user%40domain.com:secret@db.example.com:5433/production".to_string();
+
+        let action = form.handle_key(KeyEvent::new(KeyCode::Enter, KeyModifiers::NONE));
+        assert!(matches!(action, ConnectionFormAction::StatusMessage(_)));
+
+        assert_eq!(form.user, "user@domain.com");
+        assert_eq!(form.password, "secret");
+        assert_eq!(form.kind, DbKind::Postgres);
+    }
+
     #[test]
     fn test_url_paste_mongodb_sets_kind_and_uri() {
         let mut form = ConnectionFormModal::new();