Auto merge of #4314 - chansuke:add-negation-to-is_empty, r=flip1995

Add negation to `len_zero` lint to show more explicit message.

Fixes #4304 I have updated the `len_zero` to show the required negation in case of like the below case.

```
fn main() {
    let v = vec![1];
    if v.len() > 0 {
    }
}
```

changelog: Clarify suggestion of `len_zero` lint.
This commit is contained in:
bors 2019-08-01 14:09:59 +00:00
commit 18a7dce4da
2 changed files with 8 additions and 8 deletions

View File

@ -244,7 +244,7 @@ fn check_len(
LEN_ZERO,
span,
&format!("length comparison to {}", if compare_to == 0 { "zero" } else { "one" }),
"using `is_empty` is clearer and more explicit",
&format!("using `{}is_empty` is clearer and more explicit", op),
format!(
"{}{}.is_empty()",
op,

View File

@ -22,13 +22,13 @@ error: length comparison to zero
--> $DIR/len_zero.rs:83:8
|
LL | if has_is_empty.len() != 0 {
| ^^^^^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
| ^^^^^^^^^^^^^^^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
error: length comparison to zero
--> $DIR/len_zero.rs:86:8
|
LL | if has_is_empty.len() > 0 {
| ^^^^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
| ^^^^^^^^^^^^^^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
error: length comparison to one
--> $DIR/len_zero.rs:89:8
@ -40,7 +40,7 @@ error: length comparison to one
--> $DIR/len_zero.rs:92:8
|
LL | if has_is_empty.len() >= 1 {
| ^^^^^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
| ^^^^^^^^^^^^^^^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
error: length comparison to zero
--> $DIR/len_zero.rs:103:8
@ -52,19 +52,19 @@ error: length comparison to zero
--> $DIR/len_zero.rs:106:8
|
LL | if 0 != has_is_empty.len() {
| ^^^^^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
| ^^^^^^^^^^^^^^^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
error: length comparison to zero
--> $DIR/len_zero.rs:109:8
|
LL | if 0 < has_is_empty.len() {
| ^^^^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
| ^^^^^^^^^^^^^^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
error: length comparison to one
--> $DIR/len_zero.rs:112:8
|
LL | if 1 <= has_is_empty.len() {
| ^^^^^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
| ^^^^^^^^^^^^^^^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!has_is_empty.is_empty()`
error: length comparison to one
--> $DIR/len_zero.rs:115:8
@ -82,7 +82,7 @@ error: length comparison to zero
--> $DIR/len_zero.rs:142:8
|
LL | if b.len() != 0 {}
| ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!b.is_empty()`
| ^^^^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!b.is_empty()`
error: aborting due to 14 previous errors