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Oct 30, 2020
Merged

Improve suggestions for several lints #6197

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2911d9c
Use better placeholders for some methods lint messages
ThibsG Oct 18, 2020
3fec6f5
Improve some suggestions for `filter_map_next`, `filter_next` and `ma…
ThibsG Oct 19, 2020
2a3ae11
Move fixable `map_unwrap_or` cases to rustfixed test
ThibsG Oct 23, 2020
e2d86b5
Move fixable `filter_next` and `filter_map_next` cases to rustfixed t…
ThibsG Oct 23, 2020
c0dd1f9
Fix tests for `map_unwrap_or*`
ThibsG Oct 26, 2020
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88 changes: 45 additions & 43 deletions clippy_lints/src/methods/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -32,8 +32,7 @@ use crate::utils::{
is_copy, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath,
match_trait_method, match_type, match_var, method_calls, method_chain_args, paths, remove_blocks, return_ty,
single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint,
span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then, sugg, walk_ptrs_ty_depth,
SpanlessEq,
span_lint_and_help, span_lint_and_sugg, span_lint_and_then, sugg, walk_ptrs_ty_depth, SpanlessEq,
};

declare_clippy_lint! {
Expand Down Expand Up @@ -1748,7 +1747,7 @@ fn lint_or_fun_call<'tcx>(
"try this",
format!(
"{}.unwrap_or_default()",
snippet_with_applicability(cx, self_expr.span, "_", &mut applicability)
snippet_with_applicability(cx, self_expr.span, "..", &mut applicability)
),
applicability,
);
Expand Down Expand Up @@ -2155,7 +2154,7 @@ fn lint_clone_on_ref_ptr(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::
return;
};

let snippet = snippet_with_macro_callsite(cx, arg.span, "_");
let snippet = snippet_with_macro_callsite(cx, arg.span, "..");

span_lint_and_sugg(
cx,
Expand Down Expand Up @@ -2191,9 +2190,9 @@ fn lint_string_extend(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::E
"try this",
format!(
"{}.push_str({}{})",
snippet_with_applicability(cx, args[0].span, "_", &mut applicability),
snippet_with_applicability(cx, args[0].span, "..", &mut applicability),
ref_str,
snippet_with_applicability(cx, target.span, "_", &mut applicability)
snippet_with_applicability(cx, target.span, "..", &mut applicability)
),
applicability,
);
Expand Down Expand Up @@ -2460,7 +2459,7 @@ fn lint_get_unwrap<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, get_args:
let mut applicability = Applicability::MachineApplicable;
let expr_ty = cx.typeck_results().expr_ty(&get_args[0]);
let get_args_str = if get_args.len() > 1 {
snippet_with_applicability(cx, get_args[1].span, "_", &mut applicability)
snippet_with_applicability(cx, get_args[1].span, "..", &mut applicability)
} else {
return; // not linting on a .get().unwrap() chain or variant
};
Expand Down Expand Up @@ -2520,7 +2519,7 @@ fn lint_get_unwrap<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, get_args:
format!(
"{}{}[{}]",
borrow_str,
snippet_with_applicability(cx, get_args[0].span, "_", &mut applicability),
snippet_with_applicability(cx, get_args[0].span, "..", &mut applicability),
get_args_str
),
applicability,
Expand All @@ -2536,7 +2535,7 @@ fn lint_iter_skip_next(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[
cx,
ITER_SKIP_NEXT,
expr.span.trim_start(caller.span).unwrap(),
"called `skip(x).next()` on an iterator",
"called `skip(..).next()` on an iterator",
"use `nth` instead",
hint,
Applicability::MachineApplicable,
Expand Down Expand Up @@ -2739,11 +2738,11 @@ fn lint_map_unwrap_or_else<'tcx>(

// lint message
let msg = if is_option {
"called `map(f).unwrap_or_else(g)` on an `Option` value. This can be done more directly by calling \
`map_or_else(g, f)` instead"
"called `map(<f>).unwrap_or_else(<g>)` on an `Option` value. This can be done more directly by calling \
`map_or_else(<g>, <f>)` instead"
} else {
"called `map(f).unwrap_or_else(g)` on a `Result` value. This can be done more directly by calling \
`.map_or_else(g, f)` instead"
"called `map(<f>).unwrap_or_else(<g>)` on a `Result` value. This can be done more directly by calling \
`.map_or_else(<g>, <f>)` instead"
};
// get snippets for args to map() and unwrap_or_else()
let map_snippet = snippet(cx, map_args[1].span, "..");
Expand All @@ -2753,16 +2752,15 @@ fn lint_map_unwrap_or_else<'tcx>(
let multiline = map_snippet.lines().count() > 1 || unwrap_snippet.lines().count() > 1;
let same_span = map_args[1].span.ctxt() == unwrap_args[1].span.ctxt();
if same_span && !multiline {
span_lint_and_note(
let var_snippet = snippet(cx, map_args[0].span, "..");
span_lint_and_sugg(
cx,
MAP_UNWRAP_OR,
expr.span,
msg,
None,
&format!(
"replace `map({0}).unwrap_or_else({1})` with `map_or_else({1}, {0})`",
map_snippet, unwrap_snippet,
),
"try this",
format!("{}.map_or_else({}, {})", var_snippet, unwrap_snippet, map_snippet),
Applicability::MachineApplicable,
);
return true;
} else if same_span && multiline {
Expand Down Expand Up @@ -2809,8 +2807,8 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map
if is_option {
let self_snippet = snippet(cx, map_or_args[0].span, "..");
let func_snippet = snippet(cx, map_or_args[2].span, "..");
let msg = "called `map_or(None, f)` on an `Option` value. This can be done more directly by calling \
`and_then(f)` instead";
let msg = "called `map_or(None, ..)` on an `Option` value. This can be done more directly by calling \
`and_then(..)` instead";
(
OPTION_MAP_OR_NONE,
msg,
Expand Down Expand Up @@ -2848,18 +2846,20 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map
fn lint_filter_next<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, filter_args: &'tcx [hir::Expr<'_>]) {
// lint if caller of `.filter().next()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter(p).next()` on an `Iterator`. This is more succinctly expressed by calling \
`.find(p)` instead.";
let msg = "called `filter(..).next()` on an `Iterator`. This is more succinctly expressed by calling \
`.find(..)` instead.";
let filter_snippet = snippet(cx, filter_args[1].span, "..");
if filter_snippet.lines().count() <= 1 {
let iter_snippet = snippet(cx, filter_args[0].span, "..");
// add note if not multi-line
span_lint_and_note(
span_lint_and_sugg(
cx,
FILTER_NEXT,
expr.span,
msg,
None,
&format!("replace `filter({0}).next()` with `find({0})`", filter_snippet),
"try this",
format!("{}.find({})", iter_snippet, filter_snippet),
Applicability::MachineApplicable,
);
} else {
span_lint(cx, FILTER_NEXT, expr.span, msg);
Expand All @@ -2879,9 +2879,9 @@ fn lint_skip_while_next<'tcx>(
cx,
SKIP_WHILE_NEXT,
expr.span,
"called `skip_while(p).next()` on an `Iterator`",
"called `skip_while(<p>).next()` on an `Iterator`",
None,
"this is more succinctly expressed by calling `.find(!p)` instead",
"this is more succinctly expressed by calling `.find(!<p>)` instead",
);
}
}
Expand All @@ -2895,7 +2895,7 @@ fn lint_filter_map<'tcx>(
) {
// lint if caller of `.filter().map()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter(p).map(q)` on an `Iterator`";
let msg = "called `filter(..).map(..)` on an `Iterator`";
let hint = "this is more succinctly expressed by calling `.filter_map(..)` instead";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
}
Expand All @@ -2904,17 +2904,19 @@ fn lint_filter_map<'tcx>(
/// lint use of `filter_map().next()` for `Iterators`
fn lint_filter_map_next<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, filter_args: &'tcx [hir::Expr<'_>]) {
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter_map(p).next()` on an `Iterator`. This is more succinctly expressed by calling \
`.find_map(p)` instead.";
let msg = "called `filter_map(..).next()` on an `Iterator`. This is more succinctly expressed by calling \
`.find_map(..)` instead.";
let filter_snippet = snippet(cx, filter_args[1].span, "..");
if filter_snippet.lines().count() <= 1 {
span_lint_and_note(
let iter_snippet = snippet(cx, filter_args[0].span, "..");
span_lint_and_sugg(
cx,
FILTER_MAP_NEXT,
expr.span,
msg,
None,
&format!("replace `filter_map({0}).next()` with `find_map({0})`", filter_snippet),
"try this",
format!("{}.find_map({})", iter_snippet, filter_snippet),
Applicability::MachineApplicable,
);
} else {
span_lint(cx, FILTER_MAP_NEXT, expr.span, msg);
Expand All @@ -2931,7 +2933,7 @@ fn lint_find_map<'tcx>(
) {
// lint if caller of `.filter().map()` is an Iterator
if match_trait_method(cx, &map_args[0], &paths::ITERATOR) {
let msg = "called `find(p).map(q)` on an `Iterator`";
let msg = "called `find(..).map(..)` on an `Iterator`";
let hint = "this is more succinctly expressed by calling `.find_map(..)` instead";
span_lint_and_help(cx, FIND_MAP, expr.span, msg, None, hint);
}
Expand All @@ -2946,7 +2948,7 @@ fn lint_filter_map_map<'tcx>(
) {
// lint if caller of `.filter().map()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter_map(p).map(q)` on an `Iterator`";
let msg = "called `filter_map(..).map(..)` on an `Iterator`";
let hint = "this is more succinctly expressed by only calling `.filter_map(..)` instead";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
}
Expand All @@ -2961,7 +2963,7 @@ fn lint_filter_flat_map<'tcx>(
) {
// lint if caller of `.filter().flat_map()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter(p).flat_map(q)` on an `Iterator`";
let msg = "called `filter(..).flat_map(..)` on an `Iterator`";
let hint = "this is more succinctly expressed by calling `.flat_map(..)` \
and filtering by returning `iter::empty()`";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
Expand All @@ -2977,7 +2979,7 @@ fn lint_filter_map_flat_map<'tcx>(
) {
// lint if caller of `.filter_map().flat_map()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter_map(p).flat_map(q)` on an `Iterator`";
let msg = "called `filter_map(..).flat_map(..)` on an `Iterator`";
let hint = "this is more succinctly expressed by calling `.flat_map(..)` \
and filtering by returning `iter::empty()`";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
Expand Down Expand Up @@ -3148,9 +3150,9 @@ fn lint_chars_cmp(
"like this",
format!("{}{}.{}({})",
if info.eq { "" } else { "!" },
snippet_with_applicability(cx, args[0][0].span, "_", &mut applicability),
snippet_with_applicability(cx, args[0][0].span, "..", &mut applicability),
suggest,
snippet_with_applicability(cx, arg_char[0].span, "_", &mut applicability)),
snippet_with_applicability(cx, arg_char[0].span, "..", &mut applicability)),
applicability,
);

Expand Down Expand Up @@ -3197,7 +3199,7 @@ fn lint_chars_cmp_with_unwrap<'tcx>(
"like this",
format!("{}{}.{}('{}')",
if info.eq { "" } else { "!" },
snippet_with_applicability(cx, args[0][0].span, "_", &mut applicability),
snippet_with_applicability(cx, args[0][0].span, "..", &mut applicability),
suggest,
c),
applicability,
Expand Down Expand Up @@ -3272,7 +3274,7 @@ fn lint_single_char_pattern(cx: &LateContext<'_>, _expr: &hir::Expr<'_>, arg: &h
fn lint_single_char_push_string(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
let mut applicability = Applicability::MachineApplicable;
if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[1], &mut applicability) {
let base_string_snippet = snippet_with_applicability(cx, args[0].span, "_", &mut applicability);
let base_string_snippet = snippet_with_applicability(cx, args[0].span, "..", &mut applicability);
let sugg = format!("{}.push({})", base_string_snippet, extension_string);
span_lint_and_sugg(
cx,
Expand Down Expand Up @@ -3315,7 +3317,7 @@ fn lint_asref(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_re
expr.span,
&format!("this call to `{}` does nothing", call_name),
"try this",
snippet_with_applicability(cx, recvr.span, "_", &mut applicability).to_string(),
snippet_with_applicability(cx, recvr.span, "..", &mut applicability).to_string(),
applicability,
);
}
Expand Down
8 changes: 4 additions & 4 deletions clippy_lints/src/methods/option_map_unwrap_or.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -53,15 +53,15 @@ pub(super) fn lint<'tcx>(
// lint message
// comparing the snippet from source to raw text ("None") below is safe
// because we already have checked the type.
let arg = if unwrap_snippet == "None" { "None" } else { "a" };
let arg = if unwrap_snippet == "None" { "None" } else { "<a>" };
let unwrap_snippet_none = unwrap_snippet == "None";
let suggest = if unwrap_snippet_none {
"and_then(f)"
"and_then(<f>)"
} else {
"map_or(a, f)"
"map_or(<a>, <f>)"
};
let msg = &format!(
"called `map(f).unwrap_or({})` on an `Option` value. \
"called `map(<f>).unwrap_or({})` on an `Option` value. \
This can be done more directly by calling `{}` instead",
arg, suggest
);
Expand Down
3 changes: 0 additions & 3 deletions tests/ui/filter_map_next.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -3,9 +3,6 @@
fn main() {
let a = ["1", "lol", "3", "NaN", "5"];

let element: Option<i32> = a.iter().filter_map(|s| s.parse().ok()).next();
assert_eq!(element, Some(1));

#[rustfmt::skip]
let _: Option<u32> = vec![1, 2, 3, 4, 5, 6]
.into_iter()
Expand Down
17 changes: 5 additions & 12 deletions tests/ui/filter_map_next.stderr
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Original file line number Diff line number Diff line change
@@ -1,14 +1,5 @@
error: called `filter_map(p).next()` on an `Iterator`. This is more succinctly expressed by calling `.find_map(p)` instead.
--> $DIR/filter_map_next.rs:6:32
|
LL | let element: Option<i32> = a.iter().filter_map(|s| s.parse().ok()).next();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D clippy::filter-map-next` implied by `-D warnings`
= note: replace `filter_map(|s| s.parse().ok()).next()` with `find_map(|s| s.parse().ok())`

error: called `filter_map(p).next()` on an `Iterator`. This is more succinctly expressed by calling `.find_map(p)` instead.
--> $DIR/filter_map_next.rs:10:26
error: called `filter_map(..).next()` on an `Iterator`. This is more succinctly expressed by calling `.find_map(..)` instead.
--> $DIR/filter_map_next.rs:7:26
|
LL | let _: Option<u32> = vec![1, 2, 3, 4, 5, 6]
| __________________________^
Expand All @@ -19,6 +10,8 @@ LL | | if x == 2 {
LL | | })
LL | | .next();
| |_______________^
|
= note: `-D clippy::filter-map-next` implied by `-D warnings`

error: aborting due to 2 previous errors
error: aborting due to previous error

10 changes: 10 additions & 0 deletions tests/ui/filter_map_next_fixable.fixed
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Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
// run-rustfix

#![warn(clippy::all, clippy::pedantic)]

fn main() {
let a = ["1", "lol", "3", "NaN", "5"];

let element: Option<i32> = a.iter().find_map(|s| s.parse().ok());
assert_eq!(element, Some(1));
}
10 changes: 10 additions & 0 deletions tests/ui/filter_map_next_fixable.rs
View file
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Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
// run-rustfix

#![warn(clippy::all, clippy::pedantic)]

fn main() {
let a = ["1", "lol", "3", "NaN", "5"];

let element: Option<i32> = a.iter().filter_map(|s| s.parse().ok()).next();
assert_eq!(element, Some(1));
}
10 changes: 10 additions & 0 deletions tests/ui/filter_map_next_fixable.stderr
View file
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Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
error: called `filter_map(..).next()` on an `Iterator`. This is more succinctly expressed by calling `.find_map(..)` instead.
--> $DIR/filter_map_next_fixable.rs:8:32
|
LL | let element: Option<i32> = a.iter().filter_map(|s| s.parse().ok()).next();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `a.iter().find_map(|s| s.parse().ok())`
|
= note: `-D clippy::filter-map-next` implied by `-D warnings`

error: aborting due to previous error

8 changes: 4 additions & 4 deletions tests/ui/filter_methods.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
error: called `filter(p).map(q)` on an `Iterator`
error: called `filter(..).map(..)` on an `Iterator`
--> $DIR/filter_methods.rs:5:21
|
LL | let _: Vec<_> = vec![5; 6].into_iter().filter(|&x| x == 0).map(|x| x * 2).collect();
Expand All @@ -7,7 +7,7 @@ LL | let _: Vec<_> = vec![5; 6].into_iter().filter(|&x| x == 0).map(|x| x *
= note: `-D clippy::filter-map` implied by `-D warnings`
= help: this is more succinctly expressed by calling `.filter_map(..)` instead

error: called `filter(p).flat_map(q)` on an `Iterator`
error: called `filter(..).flat_map(..)` on an `Iterator`
--> $DIR/filter_methods.rs:7:21
|
LL | let _: Vec<_> = vec![5_i8; 6]
Expand All @@ -19,7 +19,7 @@ LL | | .flat_map(|x| x.checked_mul(2))
|
= help: this is more succinctly expressed by calling `.flat_map(..)` and filtering by returning `iter::empty()`

error: called `filter_map(p).flat_map(q)` on an `Iterator`
error: called `filter_map(..).flat_map(..)` on an `Iterator`
--> $DIR/filter_methods.rs:13:21
|
LL | let _: Vec<_> = vec![5_i8; 6]
Expand All @@ -31,7 +31,7 @@ LL | | .flat_map(|x| x.checked_mul(2))
|
= help: this is more succinctly expressed by calling `.flat_map(..)` and filtering by returning `iter::empty()`

error: called `filter_map(p).map(q)` on an `Iterator`
error: called `filter_map(..).map(..)` on an `Iterator`
--> $DIR/filter_methods.rs:19:21
|
LL | let _: Vec<_> = vec![5_i8; 6]
Expand Down
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