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Reuse is_expr_identity_function for flat_map_identity

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This commit is contained in:
xFrednet
2021-06-07 23:10:42 +02:00
parent 967d815a42
commit bb3b58cfcc
4 changed files with 28 additions and 38 deletions
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44
clippy_lints/src/methods/flat_map_identity.rs
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@@ -1,6 +1,5 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::{is_expr_path_def_path, is_trait_method, paths};
use if_chain::if_chain;
use clippy_utils::{is_expr_identity_function, is_trait_method};
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_lint::LateContext;
@@ -15,36 +14,15 @@ pub(super) fn check<'tcx>(
flat_map_arg: &'tcx hir::Expr<'_>,
flat_map_span: Span,
) {
if is_trait_method(cx, expr, sym::Iterator) {
let apply_lint = |message: &str| {
span_lint_and_sugg(
cx,
FLAT_MAP_IDENTITY,
flat_map_span.with_hi(expr.span.hi()),
message,
"try",
"flatten()".to_string(),
Applicability::MachineApplicable,
);
};
if_chain! {
if let hir::ExprKind::Closure(_, _, body_id, _, _) = flat_map_arg.kind;
let body = cx.tcx.hir().body(body_id);
if let hir::PatKind::Binding(_, _, binding_ident, _) = body.params[0].pat.kind;
if let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = body.value.kind;
if path.segments.len() == 1;
if path.segments[0].ident.name == binding_ident.name;
then {
apply_lint("called `flat_map(|x| x)` on an `Iterator`");
}
}
if is_expr_path_def_path(cx, flat_map_arg, &paths::CONVERT_IDENTITY) {
apply_lint("called `flat_map(std::convert::identity)` on an `Iterator`");
}
if is_trait_method(cx, expr, sym::Iterator) && is_expr_identity_function(cx, flat_map_arg) {
span_lint_and_sugg(
cx,
FLAT_MAP_IDENTITY,
flat_map_span.with_hi(expr.span.hi()),
"use of `flat_map` with an identity function",
"try",
"flatten()".to_string(),
Applicability::MachineApplicable,
);
}
}