From 4560b61cd15aa026a03a64c99ead1edf7896826f Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Tue, 31 Jan 2023 21:22:11 +0000
Subject: [PATCH] Broken tests

---
 tests/ui/closures/self-supertrait-bounds.rs   | 14 ++++++++
 .../ui/lint/unused/trait-alias-supertrait.rs  | 15 +++++++++
 .../traits/alias/dont-elaborate-non-self.rs   | 10 ++++++
 .../alias-where-clause-isnt-supertrait.rs     | 33 +++++++++++++++++++
 4 files changed, 72 insertions(+)
 create mode 100644 tests/ui/closures/self-supertrait-bounds.rs
 create mode 100644 tests/ui/lint/unused/trait-alias-supertrait.rs
 create mode 100644 tests/ui/traits/alias/dont-elaborate-non-self.rs
 create mode 100644 tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.rs

diff --git a/tests/ui/closures/self-supertrait-bounds.rs b/tests/ui/closures/self-supertrait-bounds.rs
new file mode 100644
index 00000000000..f4f1cea6b81
--- /dev/null
+++ b/tests/ui/closures/self-supertrait-bounds.rs
@@ -0,0 +1,14 @@
+// check-pass
+
+// Makes sure that we only consider `Self` supertrait predicates while
+// elaborating during closure signature deduction.
+
+#![feature(trait_alias)]
+
+trait Confusing<F> = Fn(i32) where F: Fn(u32);
+
+fn alias<T: Confusing<F>, F>(_: T, _: F) {}
+
+fn main() {
+    alias(|_| {}, |_| {});
+}
diff --git a/tests/ui/lint/unused/trait-alias-supertrait.rs b/tests/ui/lint/unused/trait-alias-supertrait.rs
new file mode 100644
index 00000000000..46f00c06bf1
--- /dev/null
+++ b/tests/ui/lint/unused/trait-alias-supertrait.rs
@@ -0,0 +1,15 @@
+// check-pass
+
+// Make sure that we only consider *Self* supertrait predicates
+// in the `unused_must_use` lint.
+
+#![feature(trait_alias)]
+#![deny(unused_must_use)]
+
+trait Foo<T> = Sized where T: Iterator;
+
+fn test<T: Iterator>() -> impl Foo<T> {}
+
+fn main() {
+    test::<std::iter::Once<()>>();
+}
diff --git a/tests/ui/traits/alias/dont-elaborate-non-self.rs b/tests/ui/traits/alias/dont-elaborate-non-self.rs
new file mode 100644
index 00000000000..4f9eaacb8ed
--- /dev/null
+++ b/tests/ui/traits/alias/dont-elaborate-non-self.rs
@@ -0,0 +1,10 @@
+#![feature(trait_alias)]
+
+use std::future::Future;
+
+trait F<Fut: Future<Output = usize>> = Fn() -> Fut;
+
+fn f<Fut>(a: dyn F<Fut>) {}
+//~^ ERROR the size for values of type `(dyn Fn() -> Fut + 'static)` cannot be known at compilation time
+
+fn main() {}
diff --git a/tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.rs b/tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.rs
new file mode 100644
index 00000000000..4a5e445d1ef
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.rs
@@ -0,0 +1,33 @@
+#![feature(trait_upcasting)]
+#![feature(trait_alias)]
+
+// Although we *elaborate* `T: Alias` to `i32: B`, we should
+// not consider `B` to be a supertrait of the type.
+trait Alias = A where i32: B;
+
+trait A {}
+
+trait B {
+    fn test(&self);
+}
+
+trait C: Alias {}
+
+impl A for () {}
+
+impl C for () {}
+
+impl B for i32 {
+    fn test(&self) {
+        println!("hi {self}");
+    }
+}
+
+fn test(x: &dyn C) -> &dyn B {
+    x
+    //~^ ERROR mismatched types
+}
+
+fn main() {
+    let x: &dyn C = &();
+}