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single_char_pattern: lint only on the argument span #2984

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Merged
merged 1 commit into from
Jul 31, 2018
Merged

single_char_pattern: lint only on the argument span #2984

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9 changes: 4 additions & 5 deletions clippy_lints/src/methods.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1889,18 +1889,17 @@ fn lint_single_char_pattern<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx hi
if let Some((Constant::Str(r), _)) = constant(cx, cx.tables, arg) {
if r.len() == 1 {
let c = r.chars().next().unwrap();
let snip = snippet(cx, expr.span, "..");
let snip = snippet(cx, arg.span, "..");
let hint = snip.replace(
&format!("\"{}\"", c.escape_default()),
&format!("'{}'", c.escape_default()));
span_lint_and_then(
span_lint_and_sugg(
cx,
SINGLE_CHAR_PATTERN,
arg.span,
"single-character string constant used as pattern",
|db| {
db.span_suggestion(expr.span, "try using a char instead", hint);
},
"try using a char instead",
hint,
);
}
}
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2 changes: 2 additions & 0 deletions tests/ui/single_char_pattern.rs
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Expand Up @@ -40,4 +40,6 @@ fn main() {

let h = HashSet::<String>::new();
h.contains("X"); // should not warn

x.replace(";", ",").split(","); // issue #2978
}
44 changes: 25 additions & 19 deletions tests/ui/single_char_pattern.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -2,111 +2,117 @@ error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:5:13
|
5 | x.split("x");
| --------^^^- help: try using a char instead: `x.split('x')`
| ^^^ help: try using a char instead: `'x'`
|
= note: `-D single-char-pattern` implied by `-D warnings`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:22:16
|
22 | x.contains("x");
| -----------^^^- help: try using a char instead: `x.contains('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:23:19
|
23 | x.starts_with("x");
| --------------^^^- help: try using a char instead: `x.starts_with('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:24:17
|
24 | x.ends_with("x");
| ------------^^^- help: try using a char instead: `x.ends_with('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:25:12
|
25 | x.find("x");
| -------^^^- help: try using a char instead: `x.find('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:26:13
|
26 | x.rfind("x");
| --------^^^- help: try using a char instead: `x.rfind('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:27:14
|
27 | x.rsplit("x");
| ---------^^^- help: try using a char instead: `x.rsplit('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:28:24
|
28 | x.split_terminator("x");
| -------------------^^^- help: try using a char instead: `x.split_terminator('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:29:25
|
29 | x.rsplit_terminator("x");
| --------------------^^^- help: try using a char instead: `x.rsplit_terminator('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:30:17
|
30 | x.splitn(0, "x");
| ------------^^^- help: try using a char instead: `x.splitn(0, 'x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:31:18
|
31 | x.rsplitn(0, "x");
| -------------^^^- help: try using a char instead: `x.rsplitn(0, 'x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:32:15
|
32 | x.matches("x");
| ----------^^^- help: try using a char instead: `x.matches('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:33:16
|
33 | x.rmatches("x");
| -----------^^^- help: try using a char instead: `x.rmatches('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:34:21
|
34 | x.match_indices("x");
| ----------------^^^- help: try using a char instead: `x.match_indices('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:35:22
|
35 | x.rmatch_indices("x");
| -----------------^^^- help: try using a char instead: `x.rmatch_indices('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:36:25
|
36 | x.trim_left_matches("x");
| --------------------^^^- help: try using a char instead: `x.trim_left_matches('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:37:26
|
37 | x.trim_right_matches("x");
| ---------------------^^^- help: try using a char instead: `x.trim_right_matches('x')`
| ^^^ help: try using a char instead: `'x'`

error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:39:13
|
39 | x.split("/n");
| --------^^^^- help: try using a char instead: `x.split('/n')`
| ^^^^ help: try using a char instead: `'/n'`

error: aborting due to 18 previous errors
error: single-character string constant used as pattern
--> $DIR/single_char_pattern.rs:44:31
|
44 | x.replace(";", ",").split(","); // issue #2978
| ^^^ help: try using a char instead: `','`

error: aborting due to 19 previous errors