1 files changed, 30 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/unused_format_specs_unfixable.rs b/src/tools/clippy/tests/ui/unused_format_specs_unfixable.rs
new file mode 100644
index 000000000..78601a348
--- /dev/null
+++ b/src/tools/clippy/tests/ui/unused_format_specs_unfixable.rs
@@ -0,0 +1,30 @@
+#![warn(clippy::unused_format_specs)]
+#![allow(unused)]
+
+macro_rules! format_args_from_macro {
+    () => {
+        format_args!("from macro")
+    };
+}
+
+fn main() {
+    // prints `.`, not `     .`
+    println!("{:5}.", format_args!(""));
+    //prints `abcde`, not `abc`
+    println!("{:.3}", format_args!("abcde"));
+
+    println!("{:5}.", format_args_from_macro!());
+
+    let args = format_args!("");
+    println!("{args:5}");
+}
+
+fn should_not_lint() {
+    println!("{}", format_args!(""));
+    // Technically the same as `{}`, but the `format_args` docs specifically mention that you can use
+    // debug formatting so allow it
+    println!("{:?}", format_args!(""));
+
+    let args = format_args!("");
+    println!("{args}");
+}