Skip to content

Closes Issue4903 #5058

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Jan 29, 2020
Merged
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions CHANGELOG.md
Original file line number Diff line number Diff line change
@@ -1284,6 +1284,7 @@ Released 2018-09-13
[`should_implement_trait`]: https://rust-lang.github.io/rust-clippy/master/index.html#should_implement_trait
[`similar_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#similar_names
[`single_char_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_char_pattern
[`single_component_path_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_component_path_imports
[`single_match`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_match
[`single_match_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_match_else
[`skip_while_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#skip_while_next
2 changes: 1 addition & 1 deletion README.md
Original file line number Diff line number Diff line change
@@ -6,7 +6,7 @@

A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.

[There are 349 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
[There are 350 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)

We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you:

5 changes: 5 additions & 0 deletions clippy_lints/src/lib.rs
Original file line number Diff line number Diff line change
@@ -284,6 +284,7 @@ pub mod replace_consts;
pub mod returns;
pub mod serde_api;
pub mod shadow;
pub mod single_component_path_imports;
pub mod slow_vector_initialization;
pub mod strings;
pub mod suspicious_trait_impl;
@@ -741,6 +742,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
&shadow::SHADOW_REUSE,
&shadow::SHADOW_SAME,
&shadow::SHADOW_UNRELATED,
&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS,
&slow_vector_initialization::SLOW_VECTOR_INITIALIZATION,
&strings::STRING_ADD,
&strings::STRING_ADD_ASSIGN,
@@ -993,6 +995,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
store.register_early_pass(|| box utils::internal_lints::ProduceIce);
store.register_late_pass(|| box let_underscore::LetUnderscore);
store.register_late_pass(|| box atomic_ordering::AtomicOrdering);
store.register_early_pass(|| box single_component_path_imports::SingleComponentPathImports);

store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![
LintId::of(&arithmetic::FLOAT_ARITHMETIC),
@@ -1296,6 +1299,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&returns::NEEDLESS_RETURN),
LintId::of(&returns::UNUSED_UNIT),
LintId::of(&serde_api::SERDE_API_MISUSE),
LintId::of(&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS),
LintId::of(&slow_vector_initialization::SLOW_VECTOR_INITIALIZATION),
LintId::of(&strings::STRING_LIT_AS_BYTES),
LintId::of(&suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL),
@@ -1431,6 +1435,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&returns::LET_AND_RETURN),
LintId::of(&returns::NEEDLESS_RETURN),
LintId::of(&returns::UNUSED_UNIT),
LintId::of(&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS),
LintId::of(&strings::STRING_LIT_AS_BYTES),
LintId::of(&tabs_in_doc_comments::TABS_IN_DOC_COMMENTS),
LintId::of(&to_digit_is_some::TO_DIGIT_IS_SOME),
8 changes: 4 additions & 4 deletions clippy_lints/src/methods/mod.rs
Original file line number Diff line number Diff line change
@@ -2310,7 +2310,7 @@ fn lint_unwrap(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, unwrap_args: &[hi
&format!("used `unwrap()` on `{}` value", kind,),
&format!(
"if you don't want to handle the `{}` case gracefully, consider \
using `expect()` to provide a better panic message",
using `expect()` to provide a better panic message",
none_value,
),
);
@@ -2679,7 +2679,7 @@ fn lint_filter_flat_map<'a, 'tcx>(
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter(p).flat_map(q)` on an `Iterator`";
let hint = "this is more succinctly expressed by calling `.flat_map(..)` \
and filtering by returning `iter::empty()`";
and filtering by returning `iter::empty()`";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, hint);
}
}
@@ -2695,7 +2695,7 @@ fn lint_filter_map_flat_map<'a, 'tcx>(
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter_map(p).flat_map(q)` on an `Iterator`";
let hint = "this is more succinctly expressed by calling `.flat_map(..)` \
and filtering by returning `iter::empty()`";
and filtering by returning `iter::empty()`";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, hint);
}
}
@@ -3148,7 +3148,7 @@ fn lint_option_as_ref_deref<'a, 'tcx>(

let msg = format!(
"called `{0}` (or with one of deref aliases) on an Option value. \
This can be done more directly by calling `{1}` instead",
This can be done more directly by calling `{1}` instead",
current_method, hint
);
span_lint_and_sugg(
61 changes: 61 additions & 0 deletions clippy_lints/src/single_component_path_imports.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,61 @@
use crate::utils::span_lint_and_sugg;
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_lint::{EarlyContext, EarlyLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::edition::Edition;
use syntax::ast::{Item, ItemKind, UseTreeKind};

declare_clippy_lint! {
/// **What it does:** Checking for imports with single component use path.
///
/// **Why is this bad?** Import with single component use path such as `use cratename;`
/// is not necessary, and thus should be removed.
///
/// **Known problems:** None.
///
/// **Example:**
///
/// ```rust, ignore
/// use regex;
///
/// fn main() {
/// regex::Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
/// }
/// ```
/// Better as
/// ```rust, ignore
/// fn main() {
/// regex::Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
/// }
/// ```
pub SINGLE_COMPONENT_PATH_IMPORTS,
style,
"imports with single component path are redundant"
}

declare_lint_pass!(SingleComponentPathImports => [SINGLE_COMPONENT_PATH_IMPORTS]);

impl EarlyLintPass for SingleComponentPathImports {
fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
if_chain! {
if cx.sess.opts.edition == Edition::Edition2018;
if !item.vis.node.is_pub();
if let ItemKind::Use(use_tree) = &item.kind;
if let segments = &use_tree.prefix.segments;
if segments.len() == 1;
if let UseTreeKind::Simple(None, _, _) = use_tree.kind;
then {
span_lint_and_sugg(
cx,
SINGLE_COMPONENT_PATH_IMPORTS,
item.span,
"this import is redundant",
"remove it entirely",
String::new(),
Applicability::MachineApplicable
);
}
}
}
}
2 changes: 1 addition & 1 deletion clippy_lints/src/types.rs
Original file line number Diff line number Diff line change
@@ -316,7 +316,7 @@ impl Types {
OPTION_OPTION,
hir_ty.span,
"consider using `Option<T>` instead of `Option<Option<T>>` or a custom \
enum if you need to distinguish all 3 cases",
enum if you need to distinguish all 3 cases",
);
return; // don't recurse into the type
}
9 changes: 8 additions & 1 deletion src/lintlist/mod.rs
Original file line number Diff line number Diff line change
@@ -6,7 +6,7 @@ pub use lint::Lint;
pub use lint::LINT_LEVELS;

// begin lint list, do not remove this comment, it’s used in `update_lints`
pub const ALL_LINTS: [Lint; 349] = [
pub const ALL_LINTS: [Lint; 350] = [
Lint {
name: "absurd_extreme_comparisons",
group: "correctness",
@@ -1855,6 +1855,13 @@ pub const ALL_LINTS: [Lint; 349] = [
deprecation: None,
module: "methods",
},
Lint {
name: "single_component_path_imports",
group: "style",
desc: "imports with single component path are redundant",
deprecation: None,
module: "single_component_path_imports",
},
Lint {
name: "single_match",
group: "style",
12 changes: 12 additions & 0 deletions tests/ui/single_component_path_imports.fixed
Original file line number Diff line number Diff line change
@@ -0,0 +1,12 @@
// run-rustfix
// compile-flags: --edition 2018
#![warn(clippy::single_component_path_imports)]
#![allow(unused_imports)]


use serde as edres;
pub use serde;

fn main() {
regex::Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
}
12 changes: 12 additions & 0 deletions tests/ui/single_component_path_imports.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,12 @@
// run-rustfix
// compile-flags: --edition 2018
#![warn(clippy::single_component_path_imports)]
#![allow(unused_imports)]

use regex;
use serde as edres;
pub use serde;

fn main() {
regex::Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
}
10 changes: 10 additions & 0 deletions tests/ui/single_component_path_imports.stderr
Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
error: this import is redundant
--> $DIR/single_component_path_imports.rs:6:1
|
LL | use regex;
| ^^^^^^^^^^ help: remove it entirely
|
= note: `-D clippy::single-component-path-imports` implied by `-D warnings`

error: aborting due to previous error