Auto merge of #6657 - ThibsG:FromIterParens, r=llogiq

Fix suggestions that need parens in `from_iter_instead_of_collect` lint

Fixes broken suggestions that need parens (i.e.: range)

Fixes: #6648

changelog: none
This commit is contained in:
bors 2021-02-10 19:37:27 +00:00
commit 3784cdf98e
4 changed files with 202 additions and 13 deletions

View file

@ -4142,20 +4142,54 @@ fn lint_from_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<
if implements_trait(cx, ty, from_iter_id, &[]) && implements_trait(cx, arg_ty, iter_id, &[]);
then {
// `expr` implements `FromIterator` trait
let iter_expr = snippet(cx, args[0].span, "..");
let iter_expr = sugg::Sugg::hir(cx, &args[0], "..").maybe_par();
let turbofish = extract_turbofish(cx, expr, ty);
let sugg = format!("{}.collect::<{}>()", iter_expr, turbofish);
span_lint_and_sugg(
cx,
FROM_ITER_INSTEAD_OF_COLLECT,
expr.span,
"usage of `FromIterator::from_iter`",
"use `.collect()` instead of `::from_iter()`",
format!("{}.collect()", iter_expr),
sugg,
Applicability::MaybeIncorrect,
);
}
}
}
fn extract_turbofish(cx: &LateContext<'_>, expr: &hir::Expr<'_>, ty: Ty<'tcx>) -> String {
if_chain! {
let call_site = expr.span.source_callsite();
if let Ok(snippet) = cx.sess().source_map().span_to_snippet(call_site);
let snippet_split = snippet.split("::").collect::<Vec<_>>();
if let Some((_, elements)) = snippet_split.split_last();
then {
// is there a type specifier? (i.e.: like `<u32>` in `collections::BTreeSet::<u32>::`)
if let Some(type_specifier) = snippet_split.iter().find(|e| e.starts_with('<') && e.ends_with('>')) {
// remove the type specifier from the path elements
let without_ts = elements.iter().filter_map(|e| {
if e == type_specifier { None } else { Some((*e).to_string()) }
}).collect::<Vec<_>>();
// join and add the type specifier at the end (i.e.: `collections::BTreeSet<u32>`)
format!("{}{}", without_ts.join("::"), type_specifier)
} else {
// type is not explicitly specified so wildcards are needed
// i.e.: 2 wildcards in `std::collections::BTreeMap<&i32, &char>`
let ty_str = ty.to_string();
let start = ty_str.find('<').unwrap_or(0);
let end = ty_str.find('>').unwrap_or_else(|| ty_str.len());
let nb_wildcard = ty_str[start..end].split(',').count();
let wildcards = format!("_{}", ", _".repeat(nb_wildcard - 1));
format!("{}<{}>", elements.join("::"), wildcards)
}
} else {
ty.to_string()
}
}
}
fn fn_header_equals(expected: hir::FnHeader, actual: hir::FnHeader) -> bool {
expected.constness == actual.constness
&& expected.unsafety == actual.unsafety

View file

@ -0,0 +1,48 @@
// run-rustfix
#![warn(clippy::from_iter_instead_of_collect)]
#![allow(unused_imports)]
use std::collections::{BTreeMap, BTreeSet, HashMap, VecDeque};
use std::iter::FromIterator;
fn main() {
let iter_expr = std::iter::repeat(5).take(5);
let _ = iter_expr.collect::<Vec<_>>();
let _ = vec![5, 5, 5, 5].iter().enumerate().collect::<HashMap<usize, &i8>>();
Vec::from_iter(vec![42u32]);
let a = vec![0, 1, 2];
assert_eq!(a, (0..3).collect::<Vec<_>>());
assert_eq!(a, (0..3).collect::<Vec<i32>>());
let mut b = (0..3).collect::<VecDeque<_>>();
b.push_back(4);
let mut b = (0..3).collect::<VecDeque<i32>>();
b.push_back(4);
{
use std::collections;
let mut b = (0..3).collect::<collections::VecDeque<i32>>();
b.push_back(4);
}
let values = [(0, 'a'), (1, 'b'), (2, 'c'), (3, 'd')];
let bm = values.iter().cloned().collect::<BTreeMap<_, _>>();
let mut bar = bm.range(0..2).collect::<BTreeMap<_, _>>();
bar.insert(&4, &'e');
let mut bts = (0..3).collect::<BTreeSet<_>>();
bts.insert(2);
{
use std::collections;
let _ = (0..3).collect::<collections::BTreeSet<_>>();
let _ = (0..3).collect::<collections::BTreeSet<u32>>();
}
for _i in [1, 2, 3].iter().collect::<Vec<_>>() {}
for _i in [1, 2, 3].iter().collect::<Vec<&i32>>() {}
}

View file

@ -1,13 +1,48 @@
#![warn(clippy::from_iter_instead_of_collect)]
// run-rustfix
use std::collections::HashMap;
#![warn(clippy::from_iter_instead_of_collect)]
#![allow(unused_imports)]
use std::collections::{BTreeMap, BTreeSet, HashMap, VecDeque};
use std::iter::FromIterator;
fn main() {
let iter_expr = std::iter::repeat(5).take(5);
Vec::from_iter(iter_expr);
let _ = Vec::from_iter(iter_expr);
HashMap::<usize, &i8>::from_iter(vec![5, 5, 5, 5].iter().enumerate());
let _ = HashMap::<usize, &i8>::from_iter(vec![5, 5, 5, 5].iter().enumerate());
Vec::from_iter(vec![42u32]);
let a = vec![0, 1, 2];
assert_eq!(a, Vec::from_iter(0..3));
assert_eq!(a, Vec::<i32>::from_iter(0..3));
let mut b = VecDeque::from_iter(0..3);
b.push_back(4);
let mut b = VecDeque::<i32>::from_iter(0..3);
b.push_back(4);
{
use std::collections;
let mut b = collections::VecDeque::<i32>::from_iter(0..3);
b.push_back(4);
}
let values = [(0, 'a'), (1, 'b'), (2, 'c'), (3, 'd')];
let bm = BTreeMap::from_iter(values.iter().cloned());
let mut bar = BTreeMap::from_iter(bm.range(0..2));
bar.insert(&4, &'e');
let mut bts = BTreeSet::from_iter(0..3);
bts.insert(2);
{
use std::collections;
let _ = collections::BTreeSet::from_iter(0..3);
let _ = collections::BTreeSet::<u32>::from_iter(0..3);
}
for _i in Vec::from_iter([1, 2, 3].iter()) {}
for _i in Vec::<&i32>::from_iter([1, 2, 3].iter()) {}
}

View file

@ -1,16 +1,88 @@
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:8:5
--> $DIR/from_iter_instead_of_collect.rs:11:13
|
LL | Vec::from_iter(iter_expr);
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `iter_expr.collect()`
LL | let _ = Vec::from_iter(iter_expr);
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `iter_expr.collect::<Vec<_>>()`
|
= note: `-D clippy::from-iter-instead-of-collect` implied by `-D warnings`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:10:5
--> $DIR/from_iter_instead_of_collect.rs:13:13
|
LL | HashMap::<usize, &i8>::from_iter(vec![5, 5, 5, 5].iter().enumerate());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `vec![5, 5, 5, 5].iter().enumerate().collect()`
LL | let _ = HashMap::<usize, &i8>::from_iter(vec![5, 5, 5, 5].iter().enumerate());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `vec![5, 5, 5, 5].iter().enumerate().collect::<HashMap<usize, &i8>>()`
error: aborting due to 2 previous errors
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:18:19
|
LL | assert_eq!(a, Vec::from_iter(0..3));
| ^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<Vec<_>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:19:19
|
LL | assert_eq!(a, Vec::<i32>::from_iter(0..3));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<Vec<i32>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:21:17
|
LL | let mut b = VecDeque::from_iter(0..3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<VecDeque<_>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:24:17
|
LL | let mut b = VecDeque::<i32>::from_iter(0..3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<VecDeque<i32>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:29:21
|
LL | let mut b = collections::VecDeque::<i32>::from_iter(0..3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<collections::VecDeque<i32>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:34:14
|
LL | let bm = BTreeMap::from_iter(values.iter().cloned());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `values.iter().cloned().collect::<BTreeMap<_, _>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:35:19
|
LL | let mut bar = BTreeMap::from_iter(bm.range(0..2));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `bm.range(0..2).collect::<BTreeMap<_, _>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:38:19
|
LL | let mut bts = BTreeSet::from_iter(0..3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<BTreeSet<_>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:42:17
|
LL | let _ = collections::BTreeSet::from_iter(0..3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<collections::BTreeSet<_>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:43:17
|
LL | let _ = collections::BTreeSet::<u32>::from_iter(0..3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<collections::BTreeSet<u32>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:46:15
|
LL | for _i in Vec::from_iter([1, 2, 3].iter()) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `[1, 2, 3].iter().collect::<Vec<_>>()`
error: usage of `FromIterator::from_iter`
--> $DIR/from_iter_instead_of_collect.rs:47:15
|
LL | for _i in Vec::<&i32>::from_iter([1, 2, 3].iter()) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `[1, 2, 3].iter().collect::<Vec<&i32>>()`
error: aborting due to 14 previous errors