From 7b7ddfa55da889b41e90243ac59a04eed832a71e Mon Sep 17 00:00:00 2001
From: Sebastian Andersson <sebastian@bittr.nu>
Date: Fri, 9 Oct 2020 20:23:03 +0200
Subject: [PATCH] Preserve raw strs for: format!(s) to s.to_string() lint
Ie:
| let s = format!(r#""hello""#);
| ^^^^^^^^^^^^^^^^^^^^^ help: consider using `.to_string()`: `r#""hello""#.to_string()`
---
clippy_lints/src/format.rs | 8 ++++++--
tests/ui/format.fixed | 3 ++-
tests/ui/format.stderr | 8 +++++++-
3 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/clippy_lints/src/format.rs b/clippy_lints/src/format.rs
index d6541010bca..26da058598e 100644
--- a/clippy_lints/src/format.rs
+++ b/clippy_lints/src/format.rs
@@ -1,6 +1,6 @@
use crate::utils::paths;
use crate::utils::{
- is_expn_of, is_type_diagnostic_item, last_path_segment, match_def_path, match_function_call, snippet,
+ is_expn_of, is_type_diagnostic_item, last_path_segment, match_def_path, match_function_call, snippet, snippet_opt,
span_lint_and_then,
};
use if_chain::if_chain;
@@ -132,7 +132,11 @@ fn on_new_v1<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<Strin
then {
// `format!("foo")` expansion contains `match () { () => [], }`
if tup.is_empty() {
- return Some(format!("{:?}.to_string()", s.as_str()));
+ if let Some(s_src) = snippet_opt(cx, lit.span) {
+ // Simulate macro expansion, converting {{ and }} to { and }.
+ let s_expand = s_src.replace("{{", "{").replace("}}", "}");
+ return Some(format!("{}.to_string()", s_expand))
+ }
} else if s.as_str().is_empty() {
return on_argumentv1_new(cx, &tup[0], arms);
}
diff --git a/tests/ui/format.fixed b/tests/ui/format.fixed
index 30651476999..740a22a07d7 100644
--- a/tests/ui/format.fixed
+++ b/tests/ui/format.fixed
@@ -13,7 +13,8 @@ fn main() {
"foo".to_string();
"{}".to_string();
"{} abc {}".to_string();
- "foo {}\n\" bar".to_string();
+ r##"foo {}
+" bar"##.to_string();
"foo".to_string();
format!("{:?}", "foo"); // Don't warn about `Debug`.
diff --git a/tests/ui/format.stderr b/tests/ui/format.stderr
index 9734492154e..96df7f37f77 100644
--- a/tests/ui/format.stderr
+++ b/tests/ui/format.stderr
@@ -25,7 +25,13 @@ LL | / format!(
LL | | r##"foo {{}}
LL | | " bar"##
LL | | );
- | |______^ help: consider using `.to_string()`: `"foo {}/n/" bar".to_string();`
+ | |______^
+ |
+help: consider using `.to_string()`
+ |
+LL | r##"foo {}
+LL | " bar"##.to_string();
+ |
error: useless use of `format!`
--> $DIR/format.rs:21:5