feat: add tests

__std/misc/src/bin/enum_test.rs

@@ -0,0 +1,19 @@
+enum Os {
+    Windows,
+    Linux,
+    Other(String),
+}
+
+fn main() {
+    let os = Os::Other("Unix".to_string());
+    match &os {
+        Os::Windows => println!("OS is Windows."),
+        Os::Other(name) if name == "Unix" => println!("OS is Unix"),
+        Os::Other(name) => println!("OS is other: {}", name),
+        _ => {} // IGNORE
+    }
+
+    // if let Os::Windows = os {
+    //     println!("OS is Windows");
+    // }
+}