Add test code

tests/ui/unwrap_literal.rs

@@ -0,0 +1,17 @@
+#![warn(clippy::unnecessary_unwrap)]
+
+fn unwrap_option() {
+    let val = Some(1).unwrap();
+    let val = Some(1).expect("this never happens");
+}
+
+fn unwrap_result() {
+    let val = Ok(1).unwrap();
+    let val = Err(1).unwrap_err();
+    let val = Ok(1).expect("this never happens");
+}
+
+fn main() {
+    unwrap_option();
+    unwrap_result();
+}