test: cover edge cases

parsing_handlers/src/java/tweak_import_declarations.rs

@@ -67,3 +67,37 @@ pub fn tweak_import_declarations(root: CSTNode<'_>) -> CSTNode<'_> {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use model::{
+        cst_node::{NonTerminal, Terminal},
+        CSTNode,
+    };
+
+    #[test]
+    fn if_the_root_is_not_a_program_we_just_return_it() {
+        let root = CSTNode::Terminal(Terminal {
+            kind: "terminal",
+            value: "not_a_program",
+            ..Default::default()
+        });
+
+        assert_eq!(super::tweak_import_declarations(root.clone()), root);
+    }
+
+    #[test]
+    fn if_somehow_the_root_is_a_terminal_node_we_just_return_it() {
+        let root = CSTNode::NonTerminal(NonTerminal {
+            kind: "program",
+            children: vec![CSTNode::Terminal(Terminal {
+                kind: "terminal",
+                value: "not_an_import_declaration",
+                ..Default::default()
+            })],
+            ..Default::default()
+        });
+
+        assert_eq!(super::tweak_import_declarations(root.clone()), root);
+    }
+}