Changes for core review

src/statement.rs

@@ -55,16 +55,17 @@ impl<'l> Statement<'l> {
         unsafe { ffi::sqlite3_column_count(self.raw.0) as usize }
     }
 
-    /// Return the name of a column in the statement
+    /// Return the name of a column.
     #[inline]
     pub fn column_name(&self, i: usize) -> &str {
+        debug_assert!(i < self.columns(), format!("column position has to be between 0 and {}", self.columns() - 1));
         unsafe {
             let ret = ffi::sqlite3_column_name(self.raw.0, i as c_int);
             c_str_to_str!(ret).unwrap()
         }
     }
 
-    /// Return column names in the statement
+    /// Return column names.
     #[inline]
     pub fn column_names(&self) -> Vec<&str> {
         (0..self.columns()).map(|i| self.column_name(i)).collect()

tests/lib.rs

@@ -137,22 +137,28 @@ fn cursor_workflow() {
 #[test]
 fn statement_columns() {
     let connection = setup_users(":memory:");
-    let statement = "SELECT id, name, age, photo as user_photo FROM users";
+    let statement = "SELECT * FROM users";
     let mut statement = ok!(connection.prepare(statement));
 
-    assert_eq!(statement.columns(), 4);
-
-    {
-        let column_names = statement.column_names();
-        assert_eq!(column_names, vec!["id", "name", "age", "user_photo"]);
-        assert_eq!("user_photo", statement.column_name(3));
-    }
-
     assert_eq!(ok!(statement.next()), State::Row);
 
     assert_eq!(statement.columns(), 4);
 }
 
+#[test]
+fn statement_column_name() {
+    let connection = setup_users(":memory:");
+    let statement = "SELECT id, name, age, photo as user_photo FROM users";
+    let statement = ok!(connection.prepare(statement));
+
+    assert_eq!(statement.columns(), 4);
+
+    let column_names = statement.column_names();
+    assert_eq!(column_names, vec!["id", "name", "age", "user_photo"]);
+    assert_eq!("user_photo", statement.column_name(3));
+
+}
+
 #[test]
 fn statement_kind() {
     let connection = setup_users(":memory:");