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move flat_map_identity to its own module

This commit is contained in:
Takayuki Maeda 2021-03-06 18:30:40 +09:00
parent f430384f04
commit 37ba779a53
2 changed files with 59 additions and 50 deletions
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57
clippy_lints/src/methods/flat_map_identity.rs Normal file
View File

@ -0,0 +1,57 @@
use crate::utils::{match_qpath, match_trait_method, paths, span_lint_and_sugg};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_lint::LateContext;
use rustc_span::source_map::Span;
use super::FLAT_MAP_IDENTITY;
/// lint use of `flat_map` for `Iterators` where `flatten` would be sufficient
pub(super) fn check<'tcx>(
cx: &LateContext<'tcx>,
expr: &'tcx hir::Expr<'_>,
flat_map_args: &'tcx [hir::Expr<'_>],
flat_map_span: Span,
) {
if match_trait_method(cx, expr, &paths::ITERATOR) {
let arg_node = &flat_map_args[1].kind;
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, _, _) = arg_node;
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(_, ref 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_chain! {
if let hir::ExprKind::Path(ref qpath) = arg_node;
if match_qpath(qpath, &paths::STD_CONVERT_IDENTITY);
then {
apply_lint("called `flat_map(std::convert::identity)` on an `Iterator`");
}
}
}
}

52
clippy_lints/src/methods/mod.rs
View File

@ -10,6 +10,7 @@ mod filter_map_identity;
mod filter_map_map;
mod filter_map_next;
mod filter_next;
mod flat_map_identity;
mod from_iter_instead_of_collect;
mod get_unwrap;
mod implicit_clone;
@ -1709,7 +1710,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
["map", "find"] => filter_map::check(cx, expr, true),
["flat_map", "filter"] => filter_flat_map::check(cx, expr, arg_lists[1], arg_lists[0]),
["flat_map", "filter_map"] => filter_map_flat_map::check(cx, expr, arg_lists[1], arg_lists[0]),
["flat_map", ..] => lint_flat_map_identity(cx, expr, arg_lists[0], method_spans[0]),
["flat_map", ..] => flat_map_identity::check(cx, expr, arg_lists[0], method_spans[0]),
["flatten", "map"] => lint_map_flatten(cx, expr, arg_lists[1]),
["is_some", "find"] => lint_search_is_some(cx, expr, "find", arg_lists[1], arg_lists[0], method_spans[1]),
["is_some", "position"] => {
@ -2755,55 +2756,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map
);
}
/// lint use of `flat_map` for `Iterators` where `flatten` would be sufficient
fn lint_flat_map_identity<'tcx>(
cx: &LateContext<'tcx>,
expr: &'tcx hir::Expr<'_>,
flat_map_args: &'tcx [hir::Expr<'_>],
flat_map_span: Span,
) {
if match_trait_method(cx, expr, &paths::ITERATOR) {
let arg_node = &flat_map_args[1].kind;
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, _, _) = arg_node;
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(_, ref 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_chain! {
if let hir::ExprKind::Path(ref qpath) = arg_node;
if match_qpath(qpath, &paths::STD_CONVERT_IDENTITY);
then {
apply_lint("called `flat_map(std::convert::identity)` on an `Iterator`");
}
}
}
}
/// lint searching an Iterator followed by `is_some()`
/// or calling `find()` on a string followed by `is_some()`
fn lint_search_is_some<'tcx>(