From 87eca014f7b0fdea8eea900d33208457b171a335 Mon Sep 17 00:00:00 2001
From: jw013 <jw013@users.noreply.github.com>
Date: Sat, 6 Jan 2024 13:53:13 -0500
Subject: [PATCH] Add test crate to test async fn and impl Future (#622)

* Add test crate to test async fn and impl Future

* Disable trait async fn for now, add TODO
---
 .../new/Cargo.toml                            |  7 +++++
 .../new/src/lib.rs                            | 29 +++++++++++++++++++
 .../old/Cargo.toml                            |  7 +++++
 .../old/src/lib.rs                            | 29 +++++++++++++++++++
 4 files changed, 72 insertions(+)
 create mode 100644 test_crates/async_impl_future_equivalence/new/Cargo.toml
 create mode 100644 test_crates/async_impl_future_equivalence/new/src/lib.rs
 create mode 100644 test_crates/async_impl_future_equivalence/old/Cargo.toml
 create mode 100644 test_crates/async_impl_future_equivalence/old/src/lib.rs

diff --git a/test_crates/async_impl_future_equivalence/new/Cargo.toml b/test_crates/async_impl_future_equivalence/new/Cargo.toml
new file mode 100644
index 00000000..984e1e0e
--- /dev/null
+++ b/test_crates/async_impl_future_equivalence/new/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+publish = false
+name = "async_impl_future_equivalence"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/test_crates/async_impl_future_equivalence/new/src/lib.rs b/test_crates/async_impl_future_equivalence/new/src/lib.rs
new file mode 100644
index 00000000..3f2d8003
--- /dev/null
+++ b/test_crates/async_impl_future_equivalence/new/src/lib.rs
@@ -0,0 +1,29 @@
+//! async fn and return position impl Future are equivalent.
+//! Switching from one to the other should NOT generate any lints
+
+use std::future::Future;
+
+pub fn switches_to_return_impl() -> impl Future {
+    async {}
+}
+
+pub async fn switches_to_async() {}
+
+pub struct S;
+
+impl S {
+    pub fn switches_to_return_impl() -> impl Future {
+        async {}
+    }
+
+    pub async fn switches_to_async() {}
+}
+
+// TODO: https://github.com/obi1kenobi/cargo-semver-checks/issues/624
+// Uncomment once the project drops support for Rust < 1.75
+//
+// #[allow(async_fn_in_trait)]
+// pub trait Trait {
+//     fn switches_to_return_impl() -> impl Future;
+//     async fn switches_to_async();
+// }
diff --git a/test_crates/async_impl_future_equivalence/old/Cargo.toml b/test_crates/async_impl_future_equivalence/old/Cargo.toml
new file mode 100644
index 00000000..984e1e0e
--- /dev/null
+++ b/test_crates/async_impl_future_equivalence/old/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+publish = false
+name = "async_impl_future_equivalence"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/test_crates/async_impl_future_equivalence/old/src/lib.rs b/test_crates/async_impl_future_equivalence/old/src/lib.rs
new file mode 100644
index 00000000..04d5c3f3
--- /dev/null
+++ b/test_crates/async_impl_future_equivalence/old/src/lib.rs
@@ -0,0 +1,29 @@
+//! async fn and return position impl Future are equivalent.
+//! Switching from one to the other should NOT generate any lints
+
+use std::future::Future;
+
+pub async fn switches_to_return_impl() {}
+
+pub fn switches_to_async() -> impl Future {
+    async {}
+}
+
+pub struct S;
+
+impl S {
+    pub async fn switches_to_return_impl() {}
+
+    pub fn switches_to_async() -> impl Future {
+        async {}
+    }
+}
+
+// TODO: https://github.com/obi1kenobi/cargo-semver-checks/issues/624
+// Uncomment once the project drops support for Rust < 1.75
+//
+// #[allow(async_fn_in_trait)]
+// pub trait Trait {
+//     async fn switches_to_return_impl();
+//     fn switches_to_async() -> impl Future;
+// }