diff options
| -rw-r--r-- | clippy_lints/src/methods/mod.rs | 9 | ||||
| -rw-r--r-- | tests/ui/from_iter_instead_of_collect.rs | 8 | ||||
| -rw-r--r-- | tests/ui/from_iter_instead_of_collect.stderr | 14 |
3 files changed, 27 insertions, 4 deletions
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 7a459a440ca..f53b2f67d1d 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -4094,14 +4094,19 @@ 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 sugg = if higher::range(&args[0]).is_some() { + format!("{}.collect::<{}>()", iter_expr, ty) + } else { + format!("{}.collect()", iter_expr) + }; 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, ); } diff --git a/tests/ui/from_iter_instead_of_collect.rs b/tests/ui/from_iter_instead_of_collect.rs index 045eb3133d3..6c81366c4df 100644 --- a/tests/ui/from_iter_instead_of_collect.rs +++ b/tests/ui/from_iter_instead_of_collect.rs @@ -1,6 +1,6 @@ #![warn(clippy::from_iter_instead_of_collect)] -use std::collections::HashMap; +use std::collections::{HashMap, VecDeque}; use std::iter::FromIterator; fn main() { @@ -10,4 +10,10 @@ fn main() { 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)); + + let mut b = VecDeque::from_iter(0..3); + b.push_back(4); } diff --git a/tests/ui/from_iter_instead_of_collect.stderr b/tests/ui/from_iter_instead_of_collect.stderr index 46bdc2f4e19..e2161dd3b57 100644 --- a/tests/ui/from_iter_instead_of_collect.stderr +++ b/tests/ui/from_iter_instead_of_collect.stderr @@ -12,5 +12,17 @@ error: usage of `FromIterator::from_iter` 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()` -error: aborting due to 2 previous errors +error: usage of `FromIterator::from_iter` + --> $DIR/from_iter_instead_of_collect.rs:15:19 + | +LL | assert_eq!(a, Vec::from_iter(0..3)); + | ^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<std::vec::Vec<i32>>()` + +error: usage of `FromIterator::from_iter` + --> $DIR/from_iter_instead_of_collect.rs:17:17 + | +LL | let mut b = VecDeque::from_iter(0..3); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `.collect()` instead of `::from_iter()`: `(0..3).collect::<std::collections::VecDeque<i32>>()` + +error: aborting due to 4 previous errors |