3 files changed, 151 insertions, 0 deletions
diff --git a/tests/ui/cloned_ref_to_slice_refs.fixed b/tests/ui/cloned_ref_to_slice_refs.fixed
new file mode 100644
index 00000000000..818c6e23259
--- /dev/null
+++ b/tests/ui/cloned_ref_to_slice_refs.fixed
@@ -0,0 +1,64 @@
+#![warn(clippy::cloned_ref_to_slice_refs)]
+
+#[derive(Clone)]
+struct Data;
+
+fn main() {
+    {
+        let data = Data;
+        let data_ref = &data;
+        let _ = std::slice::from_ref(data_ref); //~ ERROR: this call to `clone` can be replaced with `std::slice::from_ref`
+    }
+
+    {
+        let _ = std::slice::from_ref(&Data); //~ ERROR: this call to `clone` can be replaced with `std::slice::from_ref`
+    }
+
+    {
+        #[derive(Clone)]
+        struct Point(i32, i32);
+
+        let _ = std::slice::from_ref(&Point(0, 0)); //~ ERROR: this call to `clone` can be replaced with `std::slice::from_ref`
+    }
+
+    // the string was cloned with the intention to not mutate
+    {
+        struct BetterString(String);
+
+        let mut message = String::from("good");
+        let sender = BetterString(message.clone());
+
+        message.push_str("bye!");
+
+        println!("{} {}", message, sender.0)
+    }
+
+    // the string was cloned with the intention to not mutate
+    {
+        let mut x = String::from("Hello");
+        let r = &[x.clone()];
+        x.push('!');
+        println!("r = `{}', x = `{x}'", r[0]);
+    }
+
+    // mutable borrows may have the intention to clone
+    {
+        let data = Data;
+        let data_ref = &data;
+        let _ = &mut [data_ref.clone()];
+    }
+
+    // `T::clone` is used to denote a clone with side effects
+    {
+        use std::sync::Arc;
+        let data = Arc::new(Data);
+        let _ = &[Arc::clone(&data)];
+    }
+
+    // slices with multiple members can only be made from a singular reference
+    {
+        let data_1 = Data;
+        let data_2 = Data;
+        let _ = &[data_1.clone(), data_2.clone()];
+    }
+}
diff --git a/tests/ui/cloned_ref_to_slice_refs.rs b/tests/ui/cloned_ref_to_slice_refs.rs
new file mode 100644
index 00000000000..9517dbfd156
--- /dev/null
+++ b/tests/ui/cloned_ref_to_slice_refs.rs
@@ -0,0 +1,64 @@
+#![warn(clippy::cloned_ref_to_slice_refs)]
+
+#[derive(Clone)]
+struct Data;
+
+fn main() {
+    {
+        let data = Data;
+        let data_ref = &data;
+        let _ = &[data_ref.clone()]; //~ ERROR: this call to `clone` can be replaced with `std::slice::from_ref`
+    }
+
+    {
+        let _ = &[Data.clone()]; //~ ERROR: this call to `clone` can be replaced with `std::slice::from_ref`
+    }
+
+    {
+        #[derive(Clone)]
+        struct Point(i32, i32);
+
+        let _ = &[Point(0, 0).clone()]; //~ ERROR: this call to `clone` can be replaced with `std::slice::from_ref`
+    }
+
+    // the string was cloned with the intention to not mutate
+    {
+        struct BetterString(String);
+
+        let mut message = String::from("good");
+        let sender = BetterString(message.clone());
+
+        message.push_str("bye!");
+
+        println!("{} {}", message, sender.0)
+    }
+
+    // the string was cloned with the intention to not mutate
+    {
+        let mut x = String::from("Hello");
+        let r = &[x.clone()];
+        x.push('!');
+        println!("r = `{}', x = `{x}'", r[0]);
+    }
+
+    // mutable borrows may have the intention to clone
+    {
+        let data = Data;
+        let data_ref = &data;
+        let _ = &mut [data_ref.clone()];
+    }
+
+    // `T::clone` is used to denote a clone with side effects
+    {
+        use std::sync::Arc;
+        let data = Arc::new(Data);
+        let _ = &[Arc::clone(&data)];
+    }
+
+    // slices with multiple members can only be made from a singular reference
+    {
+        let data_1 = Data;
+        let data_2 = Data;
+        let _ = &[data_1.clone(), data_2.clone()];
+    }
+}
diff --git a/tests/ui/cloned_ref_to_slice_refs.stderr b/tests/ui/cloned_ref_to_slice_refs.stderr
new file mode 100644
index 00000000000..6a31d878239
--- /dev/null
+++ b/tests/ui/cloned_ref_to_slice_refs.stderr
@@ -0,0 +1,23 @@
+error: this call to `clone` can be replaced with `std::slice::from_ref`
+  --> tests/ui/cloned_ref_to_slice_refs.rs:10:17
+   |
+LL |         let _ = &[data_ref.clone()];
+   |                 ^^^^^^^^^^^^^^^^^^^ help: try: `std::slice::from_ref(data_ref)`
+   |
+   = note: `-D clippy::cloned-ref-to-slice-refs` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::cloned_ref_to_slice_refs)]`
+
+error: this call to `clone` can be replaced with `std::slice::from_ref`
+  --> tests/ui/cloned_ref_to_slice_refs.rs:14:17
+   |
+LL |         let _ = &[Data.clone()];
+   |                 ^^^^^^^^^^^^^^^ help: try: `std::slice::from_ref(&Data)`
+
+error: this call to `clone` can be replaced with `std::slice::from_ref`
+  --> tests/ui/cloned_ref_to_slice_refs.rs:21:17
+   |
+LL |         let _ = &[Point(0, 0).clone()];
+   |                 ^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::slice::from_ref(&Point(0, 0))`
+
+error: aborting due to 3 previous errors
+