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improve for_loops_over_fallibles to detect the usage of iter, iter_mut and into_iterator

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This commit is contained in:
DevAccentor 2022-06-04 11:03:11 +02:00
parent ebd357e4ab
commit 5a49918f36
7 changed files with 110 additions and 43 deletions
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40
clippy_lints/src/loops/for_loops_over_fallibles.rs
View File

@ -7,9 +7,22 @@
use rustc_span::symbol::sym;
/// Checks for `for` loops over `Option`s and `Result`s.
pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>, method_name: Option<&str>) {
let ty = cx.typeck_results().expr_ty(arg);
if is_type_diagnostic_item(cx, ty, sym::Option) {
let help_string = if let Some(method_name) = method_name {
format!(
"consider replacing `for {0} in {1}.{method_name}()` with `if let Some({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
)
} else {
format!(
"consider replacing `for {0} in {1}` with `if let Some({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
)
};
span_lint_and_help(
cx,
FOR_LOOPS_OVER_FALLIBLES,
@ -20,13 +33,22 @@ pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
snippet(cx, arg.span, "_")
),
None,
&format!(
"consider replacing `for {0} in {1}` with `if let Some({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
),
&help_string,
);
} else if is_type_diagnostic_item(cx, ty, sym::Result) {
let help_string = if let Some(method_name) = method_name {
format!(
"consider replacing `for {0} in {1}.{method_name}()` with `if let Ok({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
)
} else {
format!(
"consider replacing `for {0} in {1}` with `if let Ok({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
)
};
span_lint_and_help(
cx,
FOR_LOOPS_OVER_FALLIBLES,
@ -37,11 +59,7 @@ pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
snippet(cx, arg.span, "_")
),
None,
&format!(
"consider replacing `for {0} in {1}` with `if let Ok({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
),
&help_string,
);
}
}

12
clippy_lints/src/loops/mod.rs
View File

@ -188,6 +188,10 @@
/// for x in &res {
/// // ..
/// }
///
/// for x in res.iter() {
/// // ..
/// }
/// ```
///
/// Use instead:
@ -695,10 +699,14 @@ fn check_for_loop_arg(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
let method_name = method.ident.as_str();
// check for looping over x.iter() or x.iter_mut(), could use &x or &mut x
match method_name {
"iter" | "iter_mut" => explicit_iter_loop::check(cx, self_arg, arg, method_name),
"iter" | "iter_mut" => {
explicit_iter_loop::check(cx, self_arg, arg, method_name);
for_loops_over_fallibles::check(cx, pat, self_arg, Some(method_name));
},
"into_iter" => {
explicit_iter_loop::check(cx, self_arg, arg, method_name);
explicit_into_iter_loop::check(cx, self_arg, arg);
for_loops_over_fallibles::check(cx, pat, self_arg, Some(method_name));
},
"next" => {
next_loop_linted = iter_next_loop::check(cx, arg);
@ -708,6 +716,6 @@ fn check_for_loop_arg(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
}
if !next_loop_linted {
for_loops_over_fallibles::check(cx, pat, arg);
for_loops_over_fallibles::check(cx, pat, arg, None);
}
}

17
tests/ui/for_loops_over_fallibles.rs
View File

@ -2,7 +2,7 @@
fn for_loops_over_fallibles() {
let option = Some(1);
let result = option.ok_or("x not found");
let mut result = option.ok_or("x not found");
let v = vec![0, 1, 2];
// check over an `Option`
@ -10,11 +10,26 @@ fn for_loops_over_fallibles() {
println!("{}", x);
}
// check over an `Option`
for x in option.iter() {
println!("{}", x);
}
// check over a `Result`
for x in result {
println!("{}", x);
}
// check over a `Result`
for x in result.into_iter() {
println!("{}", x);
}
// check over a `Result`
for x in result.iter_mut() {
println!("{}", x);
}
for x in option.ok_or("x not found") {
println!("{}", x);
}

40
tests/ui/for_loops_over_fallibles.stderr
View File

@ -7,16 +7,40 @@ LL | for x in option {
= note: `-D clippy::for-loops-over-fallibles` implied by `-D warnings`
= help: consider replacing `for x in option` with `if let Some(x) = option`
error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
error: for loop over `option`, which is an `Option`. This is more readably written as an `if let` statement
--> $DIR/for_loops_over_fallibles.rs:14:14
|
LL | for x in option.iter() {
| ^^^^^^
|
= help: consider replacing `for x in option.iter()` with `if let Some(x) = option`
error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
--> $DIR/for_loops_over_fallibles.rs:19:14
|
LL | for x in result {
| ^^^^^^
|
= help: consider replacing `for x in result` with `if let Ok(x) = result`
error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
--> $DIR/for_loops_over_fallibles.rs:24:14
|
LL | for x in result.into_iter() {
| ^^^^^^
|
= help: consider replacing `for x in result.into_iter()` with `if let Ok(x) = result`
error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
--> $DIR/for_loops_over_fallibles.rs:29:14
|
LL | for x in result.iter_mut() {
| ^^^^^^
|
= help: consider replacing `for x in result.iter_mut()` with `if let Ok(x) = result`
error: for loop over `option.ok_or("x not found")`, which is a `Result`. This is more readably written as an `if let` statement
--> $DIR/for_loops_over_fallibles.rs:18:14
--> $DIR/for_loops_over_fallibles.rs:33:14
|
LL | for x in option.ok_or("x not found") {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -24,7 +48,7 @@ LL | for x in option.ok_or("x not found") {
= help: consider replacing `for x in option.ok_or("x not found")` with `if let Ok(x) = option.ok_or("x not found")`
error: you are iterating over `Iterator::next()` which is an Option; this will compile but is probably not what you want
--> $DIR/for_loops_over_fallibles.rs:24:14
--> $DIR/for_loops_over_fallibles.rs:39:14
|
LL | for x in v.iter().next() {
| ^^^^^^^^^^^^^^^
@ -32,7 +56,7 @@ LL | for x in v.iter().next() {
= note: `#[deny(clippy::iter_next_loop)]` on by default
error: for loop over `v.iter().next().and(Some(0))`, which is an `Option`. This is more readably written as an `if let` statement
--> $DIR/for_loops_over_fallibles.rs:29:14
--> $DIR/for_loops_over_fallibles.rs:44:14
|
LL | for x in v.iter().next().and(Some(0)) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -40,7 +64,7 @@ LL | for x in v.iter().next().and(Some(0)) {
= help: consider replacing `for x in v.iter().next().and(Some(0))` with `if let Some(x) = v.iter().next().and(Some(0))`
error: for loop over `v.iter().next().ok_or("x not found")`, which is a `Result`. This is more readably written as an `if let` statement
--> $DIR/for_loops_over_fallibles.rs:33:14
--> $DIR/for_loops_over_fallibles.rs:48:14
|
LL | for x in v.iter().next().ok_or("x not found") {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -48,7 +72,7 @@ LL | for x in v.iter().next().ok_or("x not found") {
= help: consider replacing `for x in v.iter().next().ok_or("x not found")` with `if let Ok(x) = v.iter().next().ok_or("x not found")`
error: this loop never actually loops
--> $DIR/for_loops_over_fallibles.rs:45:5
--> $DIR/for_loops_over_fallibles.rs:60:5
|
LL | / while let Some(x) = option {
LL | | println!("{}", x);
@ -59,7 +83,7 @@ LL | | }
= note: `#[deny(clippy::never_loop)]` on by default
error: this loop never actually loops
--> $DIR/for_loops_over_fallibles.rs:51:5
--> $DIR/for_loops_over_fallibles.rs:66:5
|
LL | / while let Ok(x) = result {
LL | | println!("{}", x);
@ -67,5 +91,5 @@ LL | | break;
LL | | }
| |_____^
error: aborting due to 8 previous errors
error: aborting due to 11 previous errors

1
tests/ui/manual_map_option.fixed
View File

@ -7,6 +7,7 @@
clippy::unit_arg,
clippy::match_ref_pats,
clippy::redundant_pattern_matching,
clippy::for_loops_over_fallibles,
dead_code
)]

1
tests/ui/manual_map_option.rs
View File

@ -7,6 +7,7 @@
clippy::unit_arg,
clippy::match_ref_pats,
clippy::redundant_pattern_matching,
clippy::for_loops_over_fallibles,
dead_code
)]

42
tests/ui/manual_map_option.stderr
View File

@ -1,5 +1,5 @@
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:14:5
--> $DIR/manual_map_option.rs:15:5
|
LL | / match Some(0) {
LL | | Some(_) => Some(2),
@ -10,7 +10,7 @@ LL | | };
= note: `-D clippy::manual-map` implied by `-D warnings`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:19:5
--> $DIR/manual_map_option.rs:20:5
|
LL | / match Some(0) {
LL | | Some(x) => Some(x + 1),
@ -19,7 +19,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| x + 1)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:24:5
--> $DIR/manual_map_option.rs:25:5
|
LL | / match Some("") {
LL | | Some(x) => Some(x.is_empty()),
@ -28,7 +28,7 @@ LL | | };
| |_____^ help: try this: `Some("").map(|x| x.is_empty())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:29:5
--> $DIR/manual_map_option.rs:30:5
|
LL | / if let Some(x) = Some(0) {
LL | | Some(!x)
@ -38,7 +38,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| !x)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:36:5
--> $DIR/manual_map_option.rs:37:5
|
LL | / match Some(0) {
LL | | Some(x) => { Some(std::convert::identity(x)) }
@ -47,7 +47,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(std::convert::identity)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:41:5
--> $DIR/manual_map_option.rs:42:5
|
LL | / match Some(&String::new()) {
LL | | Some(x) => Some(str::len(x)),
@ -56,7 +56,7 @@ LL | | };
| |_____^ help: try this: `Some(&String::new()).map(|x| str::len(x))`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:51:5
--> $DIR/manual_map_option.rs:52:5
|
LL | / match &Some([0, 1]) {
LL | | Some(x) => Some(x[0]),
@ -65,7 +65,7 @@ LL | | };
| |_____^ help: try this: `Some([0, 1]).as_ref().map(|x| x[0])`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:56:5
--> $DIR/manual_map_option.rs:57:5
|
LL | / match &Some(0) {
LL | | &Some(x) => Some(x * 2),
@ -74,7 +74,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| x * 2)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:61:5
--> $DIR/manual_map_option.rs:62:5
|
LL | / match Some(String::new()) {
LL | | Some(ref x) => Some(x.is_empty()),
@ -83,7 +83,7 @@ LL | | };
| |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:66:5
--> $DIR/manual_map_option.rs:67:5
|
LL | / match &&Some(String::new()) {
LL | | Some(x) => Some(x.len()),
@ -92,7 +92,7 @@ LL | | };
| |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:71:5
--> $DIR/manual_map_option.rs:72:5
|
LL | / match &&Some(0) {
LL | | &&Some(x) => Some(x + x),
@ -101,7 +101,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| x + x)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:84:9
--> $DIR/manual_map_option.rs:85:9
|
LL | / match &mut Some(String::new()) {
LL | | Some(x) => Some(x.push_str("")),
@ -110,7 +110,7 @@ LL | | };
| |_________^ help: try this: `Some(String::new()).as_mut().map(|x| x.push_str(""))`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:90:5
--> $DIR/manual_map_option.rs:91:5
|
LL | / match &mut Some(String::new()) {
LL | | Some(ref x) => Some(x.len()),
@ -119,7 +119,7 @@ LL | | };
| |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:95:5
--> $DIR/manual_map_option.rs:96:5
|
LL | / match &mut &Some(String::new()) {
LL | | Some(x) => Some(x.is_empty()),
@ -128,7 +128,7 @@ LL | | };
| |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:100:5
--> $DIR/manual_map_option.rs:101:5
|
LL | / match Some((0, 1, 2)) {
LL | | Some((x, y, z)) => Some(x + y + z),
@ -137,7 +137,7 @@ LL | | };
| |_____^ help: try this: `Some((0, 1, 2)).map(|(x, y, z)| x + y + z)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:105:5
--> $DIR/manual_map_option.rs:106:5
|
LL | / match Some([1, 2, 3]) {
LL | | Some([first, ..]) => Some(first),
@ -146,7 +146,7 @@ LL | | };
| |_____^ help: try this: `Some([1, 2, 3]).map(|[first, ..]| first)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:110:5
--> $DIR/manual_map_option.rs:111:5
|
LL | / match &Some((String::new(), "test")) {
LL | | Some((x, y)) => Some((y, x)),
@ -155,7 +155,7 @@ LL | | };
| |_____^ help: try this: `Some((String::new(), "test")).as_ref().map(|(x, y)| (y, x))`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:168:5
--> $DIR/manual_map_option.rs:169:5
|
LL | / match Some(0) {
LL | | Some(x) => Some(vec![x]),
@ -164,7 +164,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| vec![x])`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:173:5
--> $DIR/manual_map_option.rs:174:5
|
LL | / match option_env!("") {
LL | | Some(x) => Some(String::from(x)),
@ -173,7 +173,7 @@ LL | | };
| |_____^ help: try this: `option_env!("").map(String::from)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:193:12
--> $DIR/manual_map_option.rs:194:12
|
LL | } else if let Some(x) = Some(0) {
| ____________^
@ -184,7 +184,7 @@ LL | | };
| |_____^ help: try this: `{ Some(0).map(|x| x + 1) }`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:201:12
--> $DIR/manual_map_option.rs:202:12
|
LL | } else if let Some(x) = Some(0) {
| ____________^