58 lines
1.8 KiB
Rust
58 lines
1.8 KiB
Rust
use super::utils::get_hint_if_single_char_arg;
|
|
use clippy_utils::diagnostics::span_lint_and_sugg;
|
|
use if_chain::if_chain;
|
|
use rustc_errors::Applicability;
|
|
use rustc_hir as hir;
|
|
use rustc_lint::LateContext;
|
|
use rustc_middle::ty;
|
|
use rustc_span::symbol::Symbol;
|
|
|
|
use super::SINGLE_CHAR_PATTERN;
|
|
|
|
const PATTERN_METHODS: [(&str, usize); 19] = [
|
|
("contains", 1),
|
|
("starts_with", 1),
|
|
("ends_with", 1),
|
|
("find", 1),
|
|
("rfind", 1),
|
|
("split", 1),
|
|
("rsplit", 1),
|
|
("split_terminator", 1),
|
|
("rsplit_terminator", 1),
|
|
("splitn", 2),
|
|
("rsplitn", 2),
|
|
("matches", 1),
|
|
("rmatches", 1),
|
|
("match_indices", 1),
|
|
("rmatch_indices", 1),
|
|
("strip_prefix", 1),
|
|
("strip_suffix", 1),
|
|
("trim_start_matches", 1),
|
|
("trim_end_matches", 1),
|
|
];
|
|
|
|
/// lint for length-1 `str`s for methods in `PATTERN_METHODS`
|
|
pub(super) fn check(cx: &LateContext<'_>, _expr: &hir::Expr<'_>, method_name: Symbol, args: &[hir::Expr<'_>]) {
|
|
for &(method, pos) in &PATTERN_METHODS {
|
|
if_chain! {
|
|
if let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty_adjusted(&args[0]).kind();
|
|
if *ty.kind() == ty::Str;
|
|
if method_name.as_str() == method && args.len() > pos;
|
|
let arg = &args[pos];
|
|
let mut applicability = Applicability::MachineApplicable;
|
|
if let Some(hint) = get_hint_if_single_char_arg(cx, arg, &mut applicability);
|
|
then {
|
|
span_lint_and_sugg(
|
|
cx,
|
|
SINGLE_CHAR_PATTERN,
|
|
arg.span,
|
|
"single-character string constant used as pattern",
|
|
"try using a `char` instead",
|
|
hint,
|
|
applicability,
|
|
);
|
|
}
|
|
}
|
|
}
|
|
}
|