test: enhance Rust test snippet with trait and struct examples

tests/basic/test_repomap.py

@@ -520,8 +520,41 @@ if __name__ == "__main__":
             ),
             "rust": (
                 "test.rs",
-                'fn main() {\n    println!("Hello, World!");\n}\n',
-                "main",  # Key symbol to check
+                """// Define a trait
+trait Greeting {
+    fn greet(&self) -> String;
+}
+
+// Define a struct
+struct Person {
+    name: String,
+    age: u32,
+}
+
+// Implement the trait for Person
+impl Greeting for Person {
+    fn greet(&self) -> String {
+        format!("Hello, {}! You are {} years old.", self.name, self.age)
+    }
+}
+
+// Implementation block for Person
+impl Person {
+    fn new(name: String, age: u32) -> Self {
+        Person { name, age }
+    }
+}
+
+// Constants
+const DEFAULT_NAME: &str = "World";
+const MAX_AGE: u32 = 150;
+
+fn main() {
+    let person = Person::new(DEFAULT_NAME.to_string(), 30);
+    println!("{}", person.greet());
+}
+""",
+                "Person",  # Key symbol to check
             ),
             "typescript": (
                 "test.ts",