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| author | bors <bors@rust-lang.org> | 2020-10-09 23:14:58 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2020-10-09 23:14:58 +0000 |
| commit | 2bdadd8e7dc54651df06e0adff1c1b1e7dcf6480 (patch) | |
| tree | b3471fef1070d8876826263fbb632602d8a76d5e | |
| parent | 0b86340999c207647b797bccbb1d49f824a277df (diff) | |
| parent | 7b7ddfa55da889b41e90243ac59a04eed832a71e (diff) | |
| download | rust-2bdadd8e7dc54651df06e0adff1c1b1e7dcf6480.tar.gz rust-2bdadd8e7dc54651df06e0adff1c1b1e7dcf6480.zip | |
Auto merge of #6151 - bofh69:master, r=ebroto
Preserve raw strs for: format!(s) to s.to_string() lint
fixes #6142
clippy::useless_format will keep the source's string (after converting {{ and }} to { and }) when suggesting a change from format!() to .to_string() usage. Ie:
| let s = format!(r#""hello {{}}""#);
| ^^^^^^^^^^^^^^^^^^^^^ help: consider using `.to_string()`: `r#""hello {}""#.to_string()`
changelog: [`useless_format`]: preserve raw string literals when no arguments to `format!()` are provided.
| -rw-r--r-- | clippy_lints/src/format.rs | 8 | ||||
| -rw-r--r-- | tests/ui/format.fixed | 3 | ||||
| -rw-r--r-- | 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 |