add test fixtures

examples/test/src/clipboard.rs

@@ -0,0 +1,12 @@
+use anyhow::ensure;
+use tauri_sys::clipboard;
+
+pub async fn test() -> anyhow::Result<()> {
+    clipboard::write_text("foobar").await;
+
+    let text = clipboard::read_text().await;
+
+    ensure!(text == Some("foobar".to_string()));
+
+    Ok(())
+}