1 files changed, 56 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/positional_named_format_parameters.rs b/src/tools/clippy/tests/ui/positional_named_format_parameters.rs
new file mode 100644
index 000000000..553d8494e
--- /dev/null
+++ b/src/tools/clippy/tests/ui/positional_named_format_parameters.rs
@@ -0,0 +1,56 @@
+// run-rustfix
+#![allow(unused_must_use)]
+#![allow(named_arguments_used_positionally)] // Unstable at time of writing.
+#![warn(clippy::positional_named_format_parameters)]
+
+use std::io::Write;
+
+fn main() {
+    let mut v = Vec::new();
+    let hello = "Hello";
+
+    println!("{hello:.foo$}", foo = 2);
+    writeln!(v, "{hello:.foo$}", foo = 2);
+
+    // Warnings
+    println!("{} {1:?}", zero = 0, one = 1);
+    println!("This is a test { } {000001:?}", zero = 0, one = 1);
+    println!("Hello {1} is {2:.0$}", zero = 5, one = hello, two = 0.01);
+    println!("Hello {1:0$}!", zero = 5, one = 1);
+    println!("Hello {0:1$}!", zero = 4, one = 1);
+    println!("Hello {0:01$}!", zero = 4, one = 1);
+    println!("Hello is {1:.*}", zero = 5, one = 0.01);
+    println!("Hello is {:<6.*}", zero = 5, one = 0.01);
+    println!("{}, `{two:>8.*}` has 3", zero = hello, one = 3, two = hello);
+    println!("Hello {1} is {2:.0$}", zero = 5, one = hello, two = 0.01);
+    println!("Hello {world} {}!", world = 5);
+
+    writeln!(v, "{} {1:?}", zero = 0, one = 1);
+    writeln!(v, "This is a test { } {000001:?}", zero = 0, one = 1);
+    writeln!(v, "Hello {1} is {2:.0$}", zero = 5, one = hello, two = 0.01);
+    writeln!(v, "Hello {1:0$}!", zero = 4, one = 1);
+    writeln!(v, "Hello {0:1$}!", zero = 4, one = 1);
+    writeln!(v, "Hello {0:01$}!", zero = 4, one = 1);
+    writeln!(v, "Hello is {1:.*}", zero = 3, one = 0.01);
+    writeln!(v, "Hello is {:<6.*}", zero = 2, one = 0.01);
+    writeln!(v, "{}, `{two:>8.*}` has 3", zero = hello, one = 3, two = hello);
+    writeln!(v, "Hello {1} is {2:.0$}", zero = 1, one = hello, two = 0.01);
+    writeln!(v, "Hello {world} {}!", world = 0);
+
+    // Tests from other files
+    println!("{:w$}", w = 1);
+    println!("{:.p$}", p = 1);
+    println!("{}", v = 1);
+    println!("{:0$}", v = 1);
+    println!("{0:0$}", v = 1);
+    println!("{:0$.0$}", v = 1);
+    println!("{0:0$.0$}", v = 1);
+    println!("{0:0$.v$}", v = 1);
+    println!("{0:v$.0$}", v = 1);
+    println!("{v:0$.0$}", v = 1);
+    println!("{v:v$.0$}", v = 1);
+    println!("{v:0$.v$}", v = 1);
+    println!("{:w$}", w = 1);
+    println!("{:.p$}", p = 1);
+    println!("{:p$.w$}", 1, w = 1, p = 1);
+}