Auto merge of #68717 - petrochenkov:stabexpat, r=varkor

[rust.git] / tests / ui / format.rs

diff --git a/tests/ui/format.rs b/tests/ui/format.rs
index e9379d0a05bdd4874e6faaadc8d9154e87e55bff..b604d79cca373119935232370d9cee658c540f5c 100644 (file)
--- a/tests/ui/format.rs
+++ b/tests/ui/format.rs
@@ -1,34 +1,70 @@
+// run-rustfix
 
+#![allow(clippy::print_literal, clippy::redundant_clone)]
+#![warn(clippy::useless_format)]
 
-#![warn(useless_format)]
+struct Foo(pub String);
+
+macro_rules! foo {
+    ($($t:tt)*) => (Foo(format!($($t)*)))
+}
 
 fn main() {
     format!("foo");
+    format!("{{}}");
+    format!("{{}} abc {{}}");
+    format!(
+        r##"foo {{}}
+" bar"##
+    );
 
     format!("{}", "foo");
-    format!("{:?}", "foo"); // we only want to warn about `{}`
-    format!("{:+}", "foo"); // we only want to warn about `{}`
+    format!("{:?}", "foo"); // Don't warn about `Debug`.
+    format!("{:8}", "foo");
+    format!("{:width$}", "foo", width = 8);
+    format!("{:+}", "foo"); // Warn when the format makes no difference.
+    format!("{:<}", "foo"); // Warn when the format makes no difference.
     format!("foo {}", "bar");
     format!("{} bar", "foo");
 
     let arg: String = "".to_owned();
     format!("{}", arg);
-    format!("{:?}", arg); // we only want to warn about `{}`
-    format!("{:+}", arg); // we only want to warn about `{}`
+    format!("{:?}", arg); // Don't warn about debug.
+    format!("{:8}", arg);
+    format!("{:width$}", arg, width = 8);
+    format!("{:+}", arg); // Warn when the format makes no difference.
+    format!("{:<}", arg); // Warn when the format makes no difference.
     format!("foo {}", arg);
     format!("{} bar", arg);
 
-    // we don’t want to warn for non-string args, see #697
+    // We don’t want to warn for non-string args; see issue #697.
     format!("{}", 42);
     format!("{:?}", 42);
     format!("{:+}", 42);
     format!("foo {}", 42);
     format!("{} bar", 42);
 
-    // we only want to warn about `format!` itself
+    // We only want to warn about `format!` itself.
     println!("foo");
     println!("{}", "foo");
     println!("foo {}", "foo");
     println!("{}", 42);
     println!("foo {}", 42);
+
+    // A `format!` inside a macro should not trigger a warning.
+    foo!("should not warn");
+
+    // Precision on string means slicing without panicking on size.
+    format!("{:.1}", "foo"); // Could be `"foo"[..1]`
+    format!("{:.10}", "foo"); // Could not be `"foo"[..10]`
+    format!("{:.prec$}", "foo", prec = 1);
+    format!("{:.prec$}", "foo", prec = 10);
+
+    format!("{}", 42.to_string());
+    let x = std::path::PathBuf::from("/bar/foo/qux");
+    format!("{}", x.display().to_string());
+
+    // False positive
+    let a = "foo".to_string();
+    let _ = Some(format!("{}", a + "bar"));
 }