1 files changed, 58 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/print_in_format_impl.rs b/src/tools/clippy/tests/ui/print_in_format_impl.rs
new file mode 100644
index 000000000..64e886866
--- /dev/null
+++ b/src/tools/clippy/tests/ui/print_in_format_impl.rs
@@ -0,0 +1,58 @@
+#![allow(unused, clippy::print_literal, clippy::write_literal)]
+#![warn(clippy::print_in_format_impl)]
+use std::fmt::{Debug, Display, Error, Formatter};
+
+macro_rules! indirect {
+    () => {{ println!() }};
+}
+
+macro_rules! nested {
+    ($($tt:tt)*) => {
+        $($tt)*
+    };
+}
+
+struct Foo;
+impl Debug for Foo {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
+        static WORKS_WITH_NESTED_ITEMS: bool = true;
+
+        print!("{}", 1);
+        println!("{}", 2);
+        eprint!("{}", 3);
+        eprintln!("{}", 4);
+        nested! {
+            println!("nested");
+        };
+
+        write!(f, "{}", 5);
+        writeln!(f, "{}", 6);
+        indirect!();
+
+        Ok(())
+    }
+}
+
+impl Display for Foo {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
+        print!("Display");
+        write!(f, "Display");
+
+        Ok(())
+    }
+}
+
+struct UnnamedFormatter;
+impl Debug for UnnamedFormatter {
+    fn fmt(&self, _: &mut Formatter) -> Result<(), Error> {
+        println!("UnnamedFormatter");
+        Ok(())
+    }
+}
+
+fn main() {
+    print!("outside fmt");
+    println!("outside fmt");
+    eprint!("outside fmt");
+    eprintln!("outside fmt");
+}