1 files changed, 27 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/ok_expect.rs b/src/tools/clippy/tests/ui/ok_expect.rs
new file mode 100644
index 000000000..ff68d38c7
--- /dev/null
+++ b/src/tools/clippy/tests/ui/ok_expect.rs
@@ -0,0 +1,27 @@
+use std::io;
+
+struct MyError(()); // doesn't implement Debug
+
+#[derive(Debug)]
+struct MyErrorWithParam<T> {
+    x: T,
+}
+
+fn main() {
+    let res: Result<i32, ()> = Ok(0);
+    let _ = res.unwrap();
+
+    res.ok().expect("disaster!");
+    // the following should not warn, since `expect` isn't implemented unless
+    // the error type implements `Debug`
+    let res2: Result<i32, MyError> = Ok(0);
+    res2.ok().expect("oh noes!");
+    let res3: Result<u32, MyErrorWithParam<u8>> = Ok(0);
+    res3.ok().expect("whoof");
+    let res4: Result<u32, io::Error> = Ok(0);
+    res4.ok().expect("argh");
+    let res5: io::Result<u32> = Ok(0);
+    res5.ok().expect("oops");
+    let res6: Result<u32, &str> = Ok(0);
+    res6.ok().expect("meh");
+}