1 files changed, 74 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/partialeq_to_none.rs b/src/tools/clippy/tests/ui/partialeq_to_none.rs
new file mode 100644
index 000000000..61011b3a8
--- /dev/null
+++ b/src/tools/clippy/tests/ui/partialeq_to_none.rs
@@ -0,0 +1,74 @@
+// run-rustfix
+#![warn(clippy::partialeq_to_none)]
+
+struct Foobar;
+
+impl PartialEq<Option<()>> for Foobar {
+    fn eq(&self, _: &Option<()>) -> bool {
+        false
+    }
+}
+
+#[allow(dead_code)]
+fn foo(f: Option<u32>) -> &'static str {
+    if f != None { "yay" } else { "nay" }
+}
+
+fn foobar() -> Option<()> {
+    None
+}
+
+fn bar() -> Result<(), ()> {
+    Ok(())
+}
+
+fn optref() -> &'static &'static Option<()> {
+    &&None
+}
+
+pub fn macro_expansion() {
+    macro_rules! foo {
+        () => {
+            None::<()>
+        };
+    }
+
+    let _ = foobar() == foo!();
+    let _ = foo!() == foobar();
+    let _ = foo!() == foo!();
+}
+
+fn main() {
+    let x = Some(0);
+
+    let _ = x == None;
+    let _ = x != None;
+    let _ = None == x;
+    let _ = None != x;
+
+    if foobar() == None {}
+
+    if bar().ok() != None {}
+
+    let _ = Some(1 + 2) != None;
+
+    let _ = { Some(0) } == None;
+
+    let _ = {
+        /*
+          This comment runs long
+        */
+        Some(1)
+    } != None;
+
+    // Should not trigger, as `Foobar` is not an `Option` and has no `is_none`
+    let _ = Foobar == None;
+
+    let _ = optref() == &&None;
+    let _ = &&None != optref();
+    let _ = **optref() == None;
+    let _ = &None != *optref();
+
+    let x = Box::new(Option::<()>::None);
+    let _ = None != *x;
+}