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[redundant_guards]: lint slice::{starts_with,ends_with}

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y21 2023-11-15 20:53:43 +01:00
parent 998a311a13
commit 676f1f6ef8
1 changed files with 31 additions and 5 deletions
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36
clippy_lints/src/matches/redundant_guards.rs
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@ -102,22 +102,48 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'tcx>]) {
None,
);
} else if let Guard::If(if_expr) = guard
&& let ExprKind::MethodCall(path, recv, ..) = if_expr.kind
&& let ExprKind::MethodCall(path, recv, args, ..) = if_expr.kind
&& let Some(binding) = get_pat_binding(cx, recv, outer_arm)
{
let ty = cx.typeck_results().expr_ty(recv).peel_refs();
let slice_like = ty.is_slice() || ty.is_array();
if path.ident.name == sym!(is_empty) {
let sugg = if path.ident.name == sym!(is_empty) {
// `s if s.is_empty()` becomes ""
// `arr if arr.is_empty()` becomes []
if ty.is_str() {
emit_redundant_guards(cx, outer_arm, if_expr.span, r#""""#.into(), &binding, None)
r#""""#.into()
} else if slice_like {
emit_redundant_guards(cx, outer_arm, if_expr.span, "[]".into(), &binding, None)
"[]".into()
} else {
continue;
}
}
} else if slice_like
&& let Some(needle) = args.first()
&& let ExprKind::AddrOf(.., needle) = needle.kind
&& let ExprKind::Array(needles) = needle.kind
&& needles.iter().all(|needle| expr_can_be_pat(cx, needle))
{
// `arr if arr.starts_with(&[123])` becomes [123, ..]
// `arr if arr.ends_with(&[123])` becomes [.., 123]
let mut sugg = snippet(cx, needle.span, "<needle>").into_owned();
if path.ident.name == sym!(starts_with) {
sugg.insert_str(sugg.len() - 1, ", ..");
} else if path.ident.name == sym!(ends_with) {
sugg.insert_str(1, ".., ");
} else {
continue;
}
sugg.into()
} else {
continue;
};
emit_redundant_guards(cx, outer_arm, if_expr.span, sugg, &binding, None);
}
}
}