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use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
use clippy_utils::source::{snippet, snippet_with_applicability};
use clippy_utils::sugg::deref_closure_args;
use clippy_utils::ty::is_type_lang_item;
use clippy_utils::{is_trait_method, strip_pat_refs};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_hir::PatKind;
use rustc_lint::LateContext;
use rustc_span::source_map::Span;
use rustc_span::symbol::sym;
use super::SEARCH_IS_SOME;
/// lint searching an Iterator followed by `is_some()`
/// or calling `find()` on a string followed by `is_some()` or `is_none()`
#[allow(clippy::too_many_arguments, clippy::too_many_lines)]
pub(super) fn check<'tcx>(
cx: &LateContext<'_>,
expr: &'tcx hir::Expr<'_>,
search_method: &str,
is_some: bool,
search_recv: &hir::Expr<'_>,
search_arg: &'tcx hir::Expr<'_>,
is_some_recv: &hir::Expr<'_>,
method_span: Span,
) {
let option_check_method = if is_some { "is_some" } else { "is_none" };
// lint if caller of search is an Iterator
if is_trait_method(cx, is_some_recv, sym::Iterator) {
let msg = format!("called `{option_check_method}()` after searching an `Iterator` with `{search_method}`");
let search_snippet = snippet(cx, search_arg.span, "..");
if search_snippet.lines().count() <= 1 {
// suggest `any(|x| ..)` instead of `any(|&x| ..)` for `find(|&x| ..).is_some()`
// suggest `any(|..| *..)` instead of `any(|..| **..)` for `find(|..| **..).is_some()`
let mut applicability = Applicability::MachineApplicable;
let any_search_snippet = if_chain! {
if search_method == "find";
if let hir::ExprKind::Closure(&hir::Closure { body, .. }) = search_arg.kind;
let closure_body = cx.tcx.hir().body(body);
if let Some(closure_arg) = closure_body.params.get(0);
then {
if let hir::PatKind::Ref(..) = closure_arg.pat.kind {
Some(search_snippet.replacen('&', "", 1))
} else if let PatKind::Binding(..) = strip_pat_refs(closure_arg.pat).kind {
// `find()` provides a reference to the item, but `any` does not,
// so we should fix item usages for suggestion
if let Some(closure_sugg) = deref_closure_args(cx, search_arg) {
applicability = closure_sugg.applicability;
Some(closure_sugg.suggestion)
} else {
Some(search_snippet.to_string())
}
} else {
None
}
} else {
None
}
};
// add note if not multi-line
if is_some {
span_lint_and_sugg(
cx,
SEARCH_IS_SOME,
method_span.with_hi(expr.span.hi()),
&msg,
"use `any()` instead",
format!(
"any({})",
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
),
applicability,
);
} else {
let iter = snippet(cx, search_recv.span, "..");
span_lint_and_sugg(
cx,
SEARCH_IS_SOME,
expr.span,
&msg,
"use `!_.any()` instead",
format!(
"!{iter}.any({})",
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
),
applicability,
);
}
} else {
let hint = format!(
"this is more succinctly expressed by calling `any()`{}",
if option_check_method == "is_none" {
" with negation"
} else {
""
}
);
span_lint_and_help(cx, SEARCH_IS_SOME, expr.span, &msg, None, &hint);
}
}
// lint if `find()` is called by `String` or `&str`
else if search_method == "find" {
let is_string_or_str_slice = |e| {
let self_ty = cx.typeck_results().expr_ty(e).peel_refs();
if is_type_lang_item(cx, self_ty, hir::LangItem::String) {
true
} else {
self_ty.is_str()
}
};
if_chain! {
if is_string_or_str_slice(search_recv);
if is_string_or_str_slice(search_arg);
then {
let msg = format!("called `{option_check_method}()` after calling `find()` on a string");
match option_check_method {
"is_some" => {
let mut applicability = Applicability::MachineApplicable;
let find_arg = snippet_with_applicability(cx, search_arg.span, "..", &mut applicability);
span_lint_and_sugg(
cx,
SEARCH_IS_SOME,
method_span.with_hi(expr.span.hi()),
&msg,
"use `contains()` instead",
format!("contains({find_arg})"),
applicability,
);
},
"is_none" => {
let string = snippet(cx, search_recv.span, "..");
let mut applicability = Applicability::MachineApplicable;
let find_arg = snippet_with_applicability(cx, search_arg.span, "..", &mut applicability);
span_lint_and_sugg(
cx,
SEARCH_IS_SOME,
expr.span,
&msg,
"use `!_.contains()` instead",
format!("!{string}.contains({find_arg})"),
applicability,
);
},
_ => (),
}
}
}
}
}
|
