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Auto merge of #4634 - m-ober:feature/2320-map-or, r=llogiq

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Add real suggestion to option_map_unwrap_or

changelog: Add real suggestion to `option_map_unwrap_or`

Fixes #2320
This commit is contained in:
bors 2019-12-30 15:50:06 +00:00
commit cecaca3382
6 changed files with 271 additions and 214 deletions
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2
clippy_lints/src/methods/mod.rs
View file

@ -1167,7 +1167,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
["unwrap", ..] => lint_unwrap(cx, expr, arg_lists[0]),
["expect", "ok"] => lint_ok_expect(cx, expr, arg_lists[1]),
["expect", ..] => lint_expect(cx, expr, arg_lists[0]),
["unwrap_or", "map"] => option_map_unwrap_or::lint(cx, expr, arg_lists[1], arg_lists[0]),
["unwrap_or", "map"] => option_map_unwrap_or::lint(cx, expr, arg_lists[1], arg_lists[0], method_spans[1]),
["unwrap_or_else", "map"] => lint_map_unwrap_or_else(cx, expr, arg_lists[1], arg_lists[0]),
["map_or", ..] => lint_map_or_none(cx, expr, arg_lists[0]),
["and_then", ..] => lint_option_and_then_some(cx, expr, arg_lists[0]),

56
clippy_lints/src/methods/option_map_unwrap_or.rs
View file

@ -1,9 +1,11 @@
use crate::utils::paths;
use crate::utils::{is_copy, match_type, snippet, span_lint, span_note_and_lint};
use crate::utils::{differing_macro_contexts, paths, snippet_with_applicability, span_lint_and_then};
use crate::utils::{is_copy, match_type};
use rustc::hir::intravisit::{walk_path, NestedVisitorMap, Visitor};
use rustc::hir::{self, *};
use rustc::lint::LateContext;
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::Applicability;
use syntax::source_map::Span;
use syntax_pos::symbol::Symbol;
use super::OPTION_MAP_UNWRAP_OR;
@ -14,6 +16,7 @@ pub(super) fn lint<'a, 'tcx>(
expr: &hir::Expr<'_>,
map_args: &'tcx [hir::Expr<'_>],
unwrap_args: &'tcx [hir::Expr<'_>],
map_span: Span,
) {
// lint if the caller of `map()` is an `Option`
if match_type(cx, cx.tables.expr_ty(&map_args[0]), &paths::OPTION) {
@ -39,14 +42,19 @@ pub(super) fn lint<'a, 'tcx>(
}
}
// get snippets for args to map() and unwrap_or()
let map_snippet = snippet(cx, map_args[1].span, "..");
let unwrap_snippet = snippet(cx, unwrap_args[1].span, "..");
if differing_macro_contexts(unwrap_args[1].span, map_span) {
return;
}
let mut applicability = Applicability::MachineApplicable;
// get snippet for unwrap_or()
let unwrap_snippet = snippet_with_applicability(cx, unwrap_args[1].span, "..", &mut applicability);
// 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 suggest = if unwrap_snippet == "None" {
let unwrap_snippet_none = unwrap_snippet == "None";
let suggest = if unwrap_snippet_none {
"and_then(f)"
} else {
"map_or(a, f)"
@ -56,24 +64,24 @@ pub(super) fn lint<'a, 'tcx>(
This can be done more directly by calling `{}` instead",
arg, suggest
);
// lint, with note if neither arg is > 1 line and both map() and
// unwrap_or() have the same span
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 {
let suggest = if unwrap_snippet == "None" {
format!("and_then({})", map_snippet)
} else {
format!("map_or({}, {})", unwrap_snippet, map_snippet)
};
let note = format!(
"replace `map({}).unwrap_or({})` with `{}`",
map_snippet, unwrap_snippet, suggest
);
span_note_and_lint(cx, OPTION_MAP_UNWRAP_OR, expr.span, msg, expr.span, &note);
} else if same_span && multiline {
span_lint(cx, OPTION_MAP_UNWRAP_OR, expr.span, msg);
};
span_lint_and_then(cx, OPTION_MAP_UNWRAP_OR, expr.span, msg, |db| {
let map_arg_span = map_args[1].span;
let mut suggestion = vec![
(
map_span,
String::from(if unwrap_snippet_none { "and_then" } else { "map_or" }),
),
(expr.span.with_lo(unwrap_args[0].span.hi()), String::from("")),
];
if !unwrap_snippet_none {
suggestion.push((map_arg_span.with_hi(map_arg_span.lo()), format!("{}, ", unwrap_snippet)));
}
db.multipart_suggestion(&format!("use `{}` instead", suggest), suggestion, applicability);
});
}
}

76
tests/ui/methods.rs
View file

@ -164,81 +164,6 @@ impl Mul<T> for T {
}
}
/// Checks implementation of the following lints:
/// * `OPTION_MAP_UNWRAP_OR`
/// * `OPTION_MAP_UNWRAP_OR_ELSE`
#[rustfmt::skip]
fn option_methods() {
let opt = Some(1);
// Check `OPTION_MAP_UNWRAP_OR`.
// Single line case.
let _ = opt.map(|x| x + 1)
// Should lint even though this call is on a separate line.
.unwrap_or(0);
// Multi-line cases.
let _ = opt.map(|x| {
x + 1
}
).unwrap_or(0);
let _ = opt.map(|x| x + 1)
.unwrap_or({
0
});
// Single line `map(f).unwrap_or(None)` case.
let _ = opt.map(|x| Some(x + 1)).unwrap_or(None);
// Multi-line `map(f).unwrap_or(None)` cases.
let _ = opt.map(|x| {
Some(x + 1)
}
).unwrap_or(None);
let _ = opt
.map(|x| Some(x + 1))
.unwrap_or(None);
// macro case
let _ = opt_map!(opt, |x| x + 1).unwrap_or(0); // should not lint
// Should not lint if not copyable
let id: String = "identifier".to_string();
let _ = Some("prefix").map(|p| format!("{}.{}", p, id)).unwrap_or(id);
// ...but DO lint if the `unwrap_or` argument is not used in the `map`
let id: String = "identifier".to_string();
let _ = Some("prefix").map(|p| format!("{}.", p)).unwrap_or(id);
// Check OPTION_MAP_UNWRAP_OR_ELSE
// single line case
let _ = opt.map(|x| x + 1)
// Should lint even though this call is on a separate line.
.unwrap_or_else(|| 0);
// Multi-line cases.
let _ = opt.map(|x| {
x + 1
}
).unwrap_or_else(|| 0);
let _ = opt.map(|x| x + 1)
.unwrap_or_else(||
0
);
// Macro case.
// Should not lint.
let _ = opt_map!(opt, |x| x + 1).unwrap_or_else(|| 0);
// Issue #4144
{
let mut frequencies = HashMap::new();
let word = "foo";
frequencies
.get_mut(word)
.map(|count| {
*count += 1;
})
.unwrap_or_else(|| {
frequencies.insert(word.to_owned(), 1);
});
}
}
/// Checks implementation of `FILTER_NEXT` lint.
#[rustfmt::skip]
fn filter_next() {
@ -302,7 +227,6 @@ fn search_is_some() {
}
fn main() {
option_methods();
filter_next();
search_is_some();
}

125
tests/ui/methods.stderr
View file

@ -18,109 +18,8 @@ LL | | }
|
= note: `-D clippy::new-ret-no-self` implied by `-D warnings`
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/methods.rs:176:13
|
LL | let _ = opt.map(|x| x + 1)
| _____________^
LL | | // Should lint even though this call is on a separate line.
LL | | .unwrap_or(0);
| |____________________________^
|
= note: `-D clippy::option-map-unwrap-or` implied by `-D warnings`
= note: replace `map(|x| x + 1).unwrap_or(0)` with `map_or(0, |x| x + 1)`
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/methods.rs:180:13
|
LL | let _ = opt.map(|x| {
| _____________^
LL | | x + 1
LL | | }
LL | | ).unwrap_or(0);
| |____________________________^
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/methods.rs:184:13
|
LL | let _ = opt.map(|x| x + 1)
| _____________^
LL | | .unwrap_or({
LL | | 0
LL | | });
| |__________________^
error: called `map(f).unwrap_or(None)` on an Option value. This can be done more directly by calling `and_then(f)` instead
--> $DIR/methods.rs:189:13
|
LL | let _ = opt.map(|x| Some(x + 1)).unwrap_or(None);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: replace `map(|x| Some(x + 1)).unwrap_or(None)` with `and_then(|x| Some(x + 1))`
error: called `map(f).unwrap_or(None)` on an Option value. This can be done more directly by calling `and_then(f)` instead
--> $DIR/methods.rs:191:13
|
LL | let _ = opt.map(|x| {
| _____________^
LL | | Some(x + 1)
LL | | }
LL | | ).unwrap_or(None);
| |_____________________^
error: called `map(f).unwrap_or(None)` on an Option value. This can be done more directly by calling `and_then(f)` instead
--> $DIR/methods.rs:195:13
|
LL | let _ = opt
| _____________^
LL | | .map(|x| Some(x + 1))
LL | | .unwrap_or(None);
| |________________________^
|
= note: replace `map(|x| Some(x + 1)).unwrap_or(None)` with `and_then(|x| Some(x + 1))`
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/methods.rs:206:13
|
LL | let _ = Some("prefix").map(|p| format!("{}.", p)).unwrap_or(id);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: replace `map(|p| format!("{}.", p)).unwrap_or(id)` with `map_or(id, |p| format!("{}.", p))`
error: 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
--> $DIR/methods.rs:210:13
|
LL | let _ = opt.map(|x| x + 1)
| _____________^
LL | | // Should lint even though this call is on a separate line.
LL | | .unwrap_or_else(|| 0);
| |____________________________________^
|
= note: `-D clippy::option-map-unwrap-or-else` implied by `-D warnings`
= note: replace `map(|x| x + 1).unwrap_or_else(|| 0)` with `map_or_else(|| 0, |x| x + 1)`
error: 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
--> $DIR/methods.rs:214:13
|
LL | let _ = opt.map(|x| {
| _____________^
LL | | x + 1
LL | | }
LL | | ).unwrap_or_else(|| 0);
| |____________________________________^
error: 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
--> $DIR/methods.rs:218:13
|
LL | let _ = opt.map(|x| x + 1)
| _____________^
LL | | .unwrap_or_else(||
LL | | 0
LL | | );
| |_________________^
error: called `filter(p).next()` on an `Iterator`. This is more succinctly expressed by calling `.find(p)` instead.
--> $DIR/methods.rs:248:13
--> $DIR/methods.rs:173:13
|
LL | let _ = v.iter().filter(|&x| *x < 0).next();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -129,7 +28,7 @@ LL | let _ = v.iter().filter(|&x| *x < 0).next();
= note: replace `filter(|&x| *x < 0).next()` with `find(|&x| *x < 0)`
error: called `filter(p).next()` on an `Iterator`. This is more succinctly expressed by calling `.find(p)` instead.
--> $DIR/methods.rs:251:13
--> $DIR/methods.rs:176:13
|
LL | let _ = v.iter().filter(|&x| {
| _____________^
@ -139,7 +38,7 @@ LL | | ).next();
| |___________________________^
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:268:22
--> $DIR/methods.rs:193:22
|
LL | let _ = v.iter().find(|&x| *x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|x| *x < 0)`
@ -147,25 +46,25 @@ LL | let _ = v.iter().find(|&x| *x < 0).is_some();
= note: `-D clippy::search-is-some` implied by `-D warnings`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:269:20
--> $DIR/methods.rs:194:20
|
LL | let _ = (0..1).find(|x| **y == *x).is_some(); // one dereference less
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|x| **y == x)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:270:20
--> $DIR/methods.rs:195:20
|
LL | let _ = (0..1).find(|x| *x == 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|x| x == 0)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:271:22
--> $DIR/methods.rs:196:22
|
LL | let _ = v.iter().find(|x| **x == 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|x| *x == 0)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:274:13
--> $DIR/methods.rs:199:13
|
LL | let _ = v.iter().find(|&x| {
| _____________^
@ -175,13 +74,13 @@ LL | | ).is_some();
| |______________________________^
error: called `is_some()` after searching an `Iterator` with position. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:280:22
--> $DIR/methods.rs:205:22
|
LL | let _ = v.iter().position(|&x| x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|&x| x < 0)`
error: called `is_some()` after searching an `Iterator` with position. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:283:13
--> $DIR/methods.rs:208:13
|
LL | let _ = v.iter().position(|&x| {
| _____________^
@ -191,13 +90,13 @@ LL | | ).is_some();
| |______________________________^
error: called `is_some()` after searching an `Iterator` with rposition. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:289:22
--> $DIR/methods.rs:214:22
|
LL | let _ = v.iter().rposition(|&x| x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|&x| x < 0)`
error: called `is_some()` after searching an `Iterator` with rposition. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:292:13
--> $DIR/methods.rs:217:13
|
LL | let _ = v.iter().rposition(|&x| {
| _____________^
@ -206,5 +105,5 @@ LL | | }
LL | | ).is_some();
| |______________________________^
error: aborting due to 23 previous errors
error: aborting due to 13 previous errors

88
tests/ui/option_map_unwrap_or.rs Normal file
View file

@ -0,0 +1,88 @@
// FIXME: Add "run-rustfix" once it's supported for multipart suggestions
// aux-build:option_helpers.rs
#![warn(clippy::option_map_unwrap_or, clippy::option_map_unwrap_or_else)]
#[macro_use]
extern crate option_helpers;
use std::collections::HashMap;
/// Checks implementation of the following lints:
/// * `OPTION_MAP_UNWRAP_OR`
/// * `OPTION_MAP_UNWRAP_OR_ELSE`
#[rustfmt::skip]
fn option_methods() {
let opt = Some(1);
// Check `OPTION_MAP_UNWRAP_OR`.
// Single line case.
let _ = opt.map(|x| x + 1)
// Should lint even though this call is on a separate line.
.unwrap_or(0);
// Multi-line cases.
let _ = opt.map(|x| {
x + 1
}
).unwrap_or(0);
let _ = opt.map(|x| x + 1)
.unwrap_or({
0
});
// Single line `map(f).unwrap_or(None)` case.
let _ = opt.map(|x| Some(x + 1)).unwrap_or(None);
// Multi-line `map(f).unwrap_or(None)` cases.
let _ = opt.map(|x| {
Some(x + 1)
}
).unwrap_or(None);
let _ = opt
.map(|x| Some(x + 1))
.unwrap_or(None);
// macro case
let _ = opt_map!(opt, |x| x + 1).unwrap_or(0); // should not lint
// Should not lint if not copyable
let id: String = "identifier".to_string();
let _ = Some("prefix").map(|p| format!("{}.{}", p, id)).unwrap_or(id);
// ...but DO lint if the `unwrap_or` argument is not used in the `map`
let id: String = "identifier".to_string();
let _ = Some("prefix").map(|p| format!("{}.", p)).unwrap_or(id);
// Check OPTION_MAP_UNWRAP_OR_ELSE
// single line case
let _ = opt.map(|x| x + 1)
// Should lint even though this call is on a separate line.
.unwrap_or_else(|| 0);
// Multi-line cases.
let _ = opt.map(|x| {
x + 1
}
).unwrap_or_else(|| 0);
let _ = opt.map(|x| x + 1)
.unwrap_or_else(||
0
);
// Macro case.
// Should not lint.
let _ = opt_map!(opt, |x| x + 1).unwrap_or_else(|| 0);
// Issue #4144
{
let mut frequencies = HashMap::new();
let word = "foo";
frequencies
.get_mut(word)
.map(|count| {
*count += 1;
})
.unwrap_or_else(|| {
frequencies.insert(word.to_owned(), 1);
});
}
}
fn main() {
option_methods();
}

138
tests/ui/option_map_unwrap_or.stderr Normal file
View file

@ -0,0 +1,138 @@
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/option_map_unwrap_or.rs:20:13
|
LL | let _ = opt.map(|x| x + 1)
| _____________^
LL | | // Should lint even though this call is on a separate line.
LL | | .unwrap_or(0);
| |_____________________^
|
= note: `-D clippy::option-map-unwrap-or` implied by `-D warnings`
help: use `map_or(a, f)` instead
|
LL | let _ = opt.map_or(0, |x| x + 1);
| ^^^^^^ ^^ --
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/option_map_unwrap_or.rs:24:13
|
LL | let _ = opt.map(|x| {
| _____________^
LL | | x + 1
LL | | }
LL | | ).unwrap_or(0);
| |__________________^
|
help: use `map_or(a, f)` instead
|
LL | let _ = opt.map_or(0, |x| {
LL | x + 1
LL | }
LL | );
|
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/option_map_unwrap_or.rs:28:13
|
LL | let _ = opt.map(|x| x + 1)
| _____________^
LL | | .unwrap_or({
LL | | 0
LL | | });
| |__________^
|
help: use `map_or(a, f)` instead
|
LL | let _ = opt.map_or({
LL | 0
LL | }, |x| x + 1);
|
error: called `map(f).unwrap_or(None)` on an Option value. This can be done more directly by calling `and_then(f)` instead
--> $DIR/option_map_unwrap_or.rs:33:13
|
LL | let _ = opt.map(|x| Some(x + 1)).unwrap_or(None);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
help: use `and_then(f)` instead
|
LL | let _ = opt.and_then(|x| Some(x + 1));
| ^^^^^^^^ --
error: called `map(f).unwrap_or(None)` on an Option value. This can be done more directly by calling `and_then(f)` instead
--> $DIR/option_map_unwrap_or.rs:35:13
|
LL | let _ = opt.map(|x| {
| _____________^
LL | | Some(x + 1)
LL | | }
LL | | ).unwrap_or(None);
| |_____________________^
|
help: use `and_then(f)` instead
|
LL | let _ = opt.and_then(|x| {
LL | Some(x + 1)
LL | }
LL | );
|
error: called `map(f).unwrap_or(None)` on an Option value. This can be done more directly by calling `and_then(f)` instead
--> $DIR/option_map_unwrap_or.rs:39:13
|
LL | let _ = opt
| _____________^
LL | | .map(|x| Some(x + 1))
LL | | .unwrap_or(None);
| |________________________^
|
help: use `and_then(f)` instead
|
LL | .and_then(|x| Some(x + 1));
| ^^^^^^^^ --
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/option_map_unwrap_or.rs:50:13
|
LL | let _ = Some("prefix").map(|p| format!("{}.", p)).unwrap_or(id);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
help: use `map_or(a, f)` instead
|
LL | let _ = Some("prefix").map_or(id, |p| format!("{}.", p));
| ^^^^^^ ^^^ --
error: 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
--> $DIR/option_map_unwrap_or.rs:54:13
|
LL | let _ = opt.map(|x| x + 1)
| _____________^
LL | | // Should lint even though this call is on a separate line.
LL | | .unwrap_or_else(|| 0);
| |_____________________________^
|
= note: `-D clippy::option-map-unwrap-or-else` implied by `-D warnings`
= note: replace `map(|x| x + 1).unwrap_or_else(|| 0)` with `map_or_else(|| 0, |x| x + 1)`
error: 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
--> $DIR/option_map_unwrap_or.rs:58:13
|
LL | let _ = opt.map(|x| {
| _____________^
LL | | x + 1
LL | | }
LL | | ).unwrap_or_else(|| 0);
| |__________________________^
error: 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
--> $DIR/option_map_unwrap_or.rs:62:13
|
LL | let _ = opt.map(|x| x + 1)
| _____________^
LL | | .unwrap_or_else(||
LL | | 0
LL | | );
| |_________^
error: aborting due to 10 previous errors