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Merge pull request #3490 from phansch/extract_single_match_else_ui_test 

Extract single_match_else UI test
This commit is contained in:
Philipp Krones 2018-12-04 14:57:19 +01:00 committed by GitHub
parent 68bb900eba 3f72d4d630
commit 3f24cdf10f
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GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 177 additions and 158 deletions
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17
clippy_lints/src/matches.rs
View File

@ -45,7 +45,7 @@ declare_clippy_lint! {
"a match statement with a single nontrivial arm (i.e. where the other arm is `_ => {}`) instead of `if let`"
}
/// **What it does:** Checks for matches with a two arms where an `if let` will
/// **What it does:** Checks for matches with a two arms where an `if let else` will
/// usually suffice.
///
/// **Why is this bad?** Just readability – `if let` nests less than a `match`.
@ -53,16 +53,29 @@ declare_clippy_lint! {
/// **Known problems:** Personal style preferences may differ.
///
/// **Example:**
///
/// Using `match`:
///
/// ```rust
/// match x {
/// Some(ref foo) => bar(foo),
/// _ => bar(other_ref),
/// }
/// ```
///
/// Using `if let` with `else`:
///
/// ```rust
/// if let Some(ref foo) = x {
/// bar(foo);
/// } else {
/// bar(other_ref);
/// }
/// ```
declare_clippy_lint! {
pub SINGLE_MATCH_ELSE,
pedantic,
"a match statement with a two arms where the second arm's pattern is a wildcard instead of `if let`"
"a match statement with a two arms where the second arm's pattern is a placeholder instead of a specific match pattern"
}
/// **What it does:** Checks for matches where all arms match a reference,

16
tests/ui/matches.rs
View File

@ -14,26 +14,12 @@
#![warn(clippy::all)]
#![allow(unused, clippy::redundant_pattern_matching)]
#![warn(clippy::single_match_else, clippy::match_same_arms)]
#![warn(clippy::match_same_arms)]
enum ExprNode {
ExprAddrOf,
Butterflies,
Unicorns,
}
static NODE: ExprNode = ExprNode::Unicorns;
fn dummy() {
}
fn unwrap_addr() -> Option<&'static ExprNode> {
match ExprNode::Butterflies {
ExprNode::ExprAddrOf => Some(&NODE),
_ => { let x = 5; None },
}
}
fn ref_pats() {
{
let v = &Some(0);

262
tests/ui/matches.stderr
View File

@ -1,155 +1,171 @@
error: you seem to be trying to use match for destructuring a single pattern. Consider using `if let`
--> $DIR/matches.rs:31:5
|
31 | / match ExprNode::Butterflies {
32 | | ExprNode::ExprAddrOf => Some(&NODE),
33 | | _ => { let x = 5; None },
34 | | }
| |_____^ help: try this: `if let ExprNode::ExprAddrOf = ExprNode::Butterflies { Some(&NODE) } else { let x = 5; None }`
|
= note: `-D clippy::single-match-else` implied by `-D warnings`
error: you don't need to add `&` to all patterns
--> $DIR/matches.rs:40:9
--> $DIR/matches.rs:26:9
|
40 | / match v {
41 | | &Some(v) => println!("{:?}", v),
42 | | &None => println!("none"),
43 | | }
26 | / match v {
27 | | &Some(v) => println!("{:?}", v),
28 | | &None => println!("none"),
29 | | }
| |_________^
|
= note: `-D clippy::match-ref-pats` implied by `-D warnings`
help: instead of prefixing all patterns with `&`, you can dereference the expression
|
40 | match *v {
41 | Some(v) => println!("{:?}", v),
42 | None => println!("none"),
26 | match *v {
27 | Some(v) => println!("{:?}", v),
28 | None => println!("none"),
|
error: you seem to be trying to use match for destructuring a single pattern. Consider using `if let`
--> $DIR/matches.rs:50:5
|
50 | / match tup {
51 | | &(v, 1) => println!("{}", v),
52 | | _ => println!("none"),
53 | | }
| |_____^ help: try this: `if let &(v, 1) = tup { println!("{}", v) } else { println!("none") }`
error: you don't need to add `&` to all patterns
--> $DIR/matches.rs:50:5
--> $DIR/matches.rs:36:5
|
50 | / match tup {
51 | | &(v, 1) => println!("{}", v),
52 | | _ => println!("none"),
53 | | }
36 | / match tup {
37 | | &(v, 1) => println!("{}", v),
38 | | _ => println!("none"),
39 | | }
| |_____^
help: instead of prefixing all patterns with `&`, you can dereference the expression
|
50 | match *tup {
51 | (v, 1) => println!("{}", v),
36 | match *tup {
37 | (v, 1) => println!("{}", v),
|
error: you don't need to add `&` to both the expression and the patterns
--> $DIR/matches.rs:56:5
--> $DIR/matches.rs:42:5
|
56 | / match &w {
57 | | &Some(v) => println!("{:?}", v),
58 | | &None => println!("none"),
59 | | }
42 | / match &w {
43 | | &Some(v) => println!("{:?}", v),
44 | | &None => println!("none"),
45 | | }
| |_____^
help: try
|
56 | match w {
57 | Some(v) => println!("{:?}", v),
58 | None => println!("none"),
42 | match w {
43 | Some(v) => println!("{:?}", v),
44 | None => println!("none"),
|
error: you don't need to add `&` to all patterns
--> $DIR/matches.rs:67:5
--> $DIR/matches.rs:53:5
|
67 | / if let &None = a {
68 | | println!("none");
69 | | }
53 | / if let &None = a {
54 | | println!("none");
55 | | }
| |_____^
help: instead of prefixing all patterns with `&`, you can dereference the expression
|
67 | if let None = *a {
53 | if let None = *a {
| ^^^^ ^^
error: you don't need to add `&` to both the expression and the patterns
--> $DIR/matches.rs:72:5
--> $DIR/matches.rs:58:5
|
72 | / if let &None = &b {
73 | | println!("none");
74 | | }
58 | / if let &None = &b {
59 | | println!("none");
60 | | }
| |_____^
help: try
|
72 | if let None = b {
58 | if let None = b {
| ^^^^ ^
error: Err(_) will match all errors, maybe not a good idea
--> $DIR/matches.rs:83:9
--> $DIR/matches.rs:69:9
|
83 | Err(_) => panic!("err")
69 | Err(_) => panic!("err")
| ^^^^^^
|
= note: `-D clippy::match-wild-err-arm` implied by `-D warnings`
= note: to remove this warning, match each error separately or use unreachable macro
error: this `match` has identical arm bodies
--> $DIR/matches.rs:82:18
--> $DIR/matches.rs:68:18
|
82 | Ok(_) => println!("ok"),
68 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
= note: `-D clippy::match-same-arms` implied by `-D warnings`
note: same as this
--> $DIR/matches.rs:81:18
--> $DIR/matches.rs:67:18
|
81 | Ok(3) => println!("ok"),
67 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:81:18
--> $DIR/matches.rs:67:18
|
81 | Ok(3) => println!("ok"),
67 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: Err(_) will match all errors, maybe not a good idea
--> $DIR/matches.rs:89:9
--> $DIR/matches.rs:75:9
|
89 | Err(_) => {panic!()}
75 | Err(_) => {panic!()}
| ^^^^^^
|
= note: to remove this warning, match each error separately or use unreachable macro
error: this `match` has identical arm bodies
--> $DIR/matches.rs:88:18
--> $DIR/matches.rs:74:18
|
88 | Ok(_) => println!("ok"),
74 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:87:18
--> $DIR/matches.rs:73:18
|
87 | Ok(3) => println!("ok"),
73 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:87:18
--> $DIR/matches.rs:73:18
|
87 | Ok(3) => println!("ok"),
73 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: Err(_) will match all errors, maybe not a good idea
--> $DIR/matches.rs:95:9
--> $DIR/matches.rs:81:9
|
95 | Err(_) => {panic!();}
81 | Err(_) => {panic!();}
| ^^^^^^
|
= note: to remove this warning, match each error separately or use unreachable macro
error: this `match` has identical arm bodies
--> $DIR/matches.rs:80:18
|
80 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:79:18
|
79 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:79:18
|
79 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: this `match` has identical arm bodies
--> $DIR/matches.rs:87:18
|
87 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:86:18
|
86 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:86:18
|
86 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: this `match` has identical arm bodies
--> $DIR/matches.rs:94:18
|
@ -169,134 +185,98 @@ note: consider refactoring into `Ok(3) | Ok(_)`
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: this `match` has identical arm bodies
--> $DIR/matches.rs:101:18
|
101 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:100:18
|
100 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:100:18
|
100 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: this `match` has identical arm bodies
--> $DIR/matches.rs:108:18
|
108 | Ok(_) => println!("ok"),
100 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:107:18
--> $DIR/matches.rs:99:18
|
107 | Ok(3) => println!("ok"),
99 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:107:18
--> $DIR/matches.rs:99:18
|
107 | Ok(3) => println!("ok"),
99 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: this `match` has identical arm bodies
--> $DIR/matches.rs:114:18
--> $DIR/matches.rs:106:18
|
114 | Ok(_) => println!("ok"),
106 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:113:18
--> $DIR/matches.rs:105:18
|
113 | Ok(3) => println!("ok"),
105 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:113:18
--> $DIR/matches.rs:105:18
|
113 | Ok(3) => println!("ok"),
105 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: this `match` has identical arm bodies
--> $DIR/matches.rs:120:18
--> $DIR/matches.rs:127:29
|
120 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:119:18
|
119 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:119:18
|
119 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: this `match` has identical arm bodies
--> $DIR/matches.rs:141:29
|
141 | (Ok(_), Some(x)) => println!("ok {}", x),
127 | (Ok(_), Some(x)) => println!("ok {}", x),
| ^^^^^^^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:140:29
--> $DIR/matches.rs:126:29
|
140 | (Ok(x), Some(_)) => println!("ok {}", x),
126 | (Ok(x), Some(_)) => println!("ok {}", x),
| ^^^^^^^^^^^^^^^^^^^^
note: consider refactoring into `(Ok(x), Some(_)) | (Ok(_), Some(x))`
--> $DIR/matches.rs:140:29
--> $DIR/matches.rs:126:29
|
140 | (Ok(x), Some(_)) => println!("ok {}", x),
126 | (Ok(x), Some(_)) => println!("ok {}", x),
| ^^^^^^^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: this `match` has identical arm bodies
--> $DIR/matches.rs:156:18
--> $DIR/matches.rs:142:18
|
156 | Ok(_) => println!("ok"),
142 | Ok(_) => println!("ok"),
| ^^^^^^^^^^^^^^
|
note: same as this
--> $DIR/matches.rs:155:18
--> $DIR/matches.rs:141:18
|
155 | Ok(3) => println!("ok"),
141 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
note: consider refactoring into `Ok(3) | Ok(_)`
--> $DIR/matches.rs:155:18
--> $DIR/matches.rs:141:18
|
155 | Ok(3) => println!("ok"),
141 | Ok(3) => println!("ok"),
| ^^^^^^^^^^^^^^
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error: use as_ref() instead
--> $DIR/matches.rs:163:33
--> $DIR/matches.rs:149:33
|
163 | let borrowed: Option<&()> = match owned {
149 | let borrowed: Option<&()> = match owned {
| _________________________________^
164 | | None => None,
165 | | Some(ref v) => Some(v),
166 | | };
150 | | None => None,
151 | | Some(ref v) => Some(v),
152 | | };
| |_____^ help: try this: `owned.as_ref()`
|
= note: `-D clippy::match-as-ref` implied by `-D warnings`
error: use as_mut() instead
--> $DIR/matches.rs:169:39
--> $DIR/matches.rs:155:39
|
169 | let borrow_mut: Option<&mut ()> = match mut_owned {
155 | let borrow_mut: Option<&mut ()> = match mut_owned {
| _______________________________________^
170 | | None => None,
171 | | Some(ref mut v) => Some(v),
172 | | };
156 | | None => None,
157 | | Some(ref mut v) => Some(v),
158 | | };
| |_____^ help: try this: `mut_owned.as_mut()`
error: aborting due to 21 previous errors
error: aborting due to 19 previous errors

27
tests/ui/single_match_else.rs Normal file
View File

@ -0,0 +1,27 @@
// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![warn(clippy::single_match_else)]
enum ExprNode {
ExprAddrOf,
Butterflies,
Unicorns,
}
static NODE: ExprNode = ExprNode::Unicorns;
fn unwrap_addr() -> Option<&'static ExprNode> {
match ExprNode::Butterflies {
ExprNode::ExprAddrOf => Some(&NODE),
_ => { let x = 5; None },
}
}
fn main() {}

13
tests/ui/single_match_else.stderr Normal file
View File

@ -0,0 +1,13 @@
error: you seem to be trying to use match for destructuring a single pattern. Consider using `if let`
--> $DIR/single_match_else.rs:21:5
|
21 | / match ExprNode::Butterflies {
22 | | ExprNode::ExprAddrOf => Some(&NODE),
23 | | _ => { let x = 5; None },
24 | | }
| |_____^ help: try this: `if let ExprNode::ExprAddrOf = ExprNode::Butterflies { Some(&NODE) } else { let x = 5; None }`
|
= note: `-D clippy::single-match-else` implied by `-D warnings`
error: aborting due to previous error