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fix option_if_let_else when Err variant is ignored #14429

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Merged
merged 1 commit into from
Sep 18, 2025
Merged

fix option_if_let_else when Err variant is ignored #14429

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10 changes: 10 additions & 0 deletions tests/ui/option_if_let_else.fixed
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Original file line number Diff line number Diff line change
Expand Up @@ -125,6 +125,16 @@ fn complex_subpat() -> DummyEnum {
DummyEnum::Two
}

// #10335
pub fn test_result_err_ignored_1(r: Result<&[u8], &[u8]>) -> Vec<u8> {
r.map_or_else(|_| Vec::new(), |s| s.to_owned())
}

// #10335
pub fn test_result_err_ignored_2(r: Result<&[u8], &[u8]>) -> Vec<u8> {
r.map_or_else(|_| Vec::new(), |s| s.to_owned())
}

fn main() {
let optional = Some(5);
let _ = optional.map_or(5, |x| x + 2);
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16 changes: 16 additions & 0 deletions tests/ui/option_if_let_else.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -152,6 +152,22 @@ fn complex_subpat() -> DummyEnum {
DummyEnum::Two
}

// #10335
pub fn test_result_err_ignored_1(r: Result<&[u8], &[u8]>) -> Vec<u8> {
match r {
//~^ option_if_let_else
Ok(s) => s.to_owned(),
Err(_) => Vec::new(),
}
}

// #10335
pub fn test_result_err_ignored_2(r: Result<&[u8], &[u8]>) -> Vec<u8> {
if let Ok(s) = r { s.to_owned() }
//~^ option_if_let_else
else { Vec::new() }
}

fn main() {
let optional = Some(5);
let _ = if let Some(x) = optional { x + 2 } else { 5 };
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50 changes: 34 additions & 16 deletions tests/ui/option_if_let_else.stderr
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Expand Up @@ -188,14 +188,32 @@ LL + true
LL + })
|

error: use Option::map_or_else instead of an if let/else
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issue: this lint says Option, and has Option in its name, we should probably not be linting here?

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I guess we already lint on Result here.

Tbh I'm not convinced of the value of this lint overall, we should probably have a team discussion about it, but separately to that we shoudl figure out if it should also handle Result in the same lint (and if so, it needs to be updated)

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That's a separate issue from fixing what currently exists.

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Zulip thead started here.

--> tests/ui/option_if_let_else.rs:157:5
|
LL | / match r {
LL | |
LL | | Ok(s) => s.to_owned(),
LL | | Err(_) => Vec::new(),
LL | | }
| |_____^ help: try: `r.map_or_else(|_| Vec::new(), |s| s.to_owned())`

error: use Option::map_or_else instead of an if let/else
--> tests/ui/option_if_let_else.rs:166:5
|
LL | / if let Ok(s) = r { s.to_owned() }
LL | |
LL | | else { Vec::new() }
| |_______________________^ help: try: `r.map_or_else(|_| Vec::new(), |s| s.to_owned())`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:157:13
--> tests/ui/option_if_let_else.rs:173:13
|
LL | let _ = if let Some(x) = optional { x + 2 } else { 5 };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `optional.map_or(5, |x| x + 2)`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:168:13
--> tests/ui/option_if_let_else.rs:184:13
|
LL | let _ = if let Some(x) = Some(0) {
| _____________^
Expand All @@ -217,13 +235,13 @@ LL ~ });
|

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:197:13
--> tests/ui/option_if_let_else.rs:213:13
|
LL | let _ = if let Some(x) = Some(0) { s.len() + x } else { s.len() };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Some(0).map_or(s.len(), |x| s.len() + x)`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:202:13
--> tests/ui/option_if_let_else.rs:218:13
|
LL | let _ = if let Some(x) = Some(0) {
| _____________^
Expand All @@ -245,7 +263,7 @@ LL ~ });
|

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:242:13
--> tests/ui/option_if_let_else.rs:258:13
|
LL | let _ = match s {
| _____________^
Expand All @@ -256,7 +274,7 @@ LL | | };
| |_____^ help: try: `s.map_or(1, |string| string.len())`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:247:13
--> tests/ui/option_if_let_else.rs:263:13
|
LL | let _ = match Some(10) {
| _____________^
Expand All @@ -267,7 +285,7 @@ LL | | };
| |_____^ help: try: `Some(10).map_or(5, |a| a + 1)`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:254:13
--> tests/ui/option_if_let_else.rs:270:13
|
LL | let _ = match res {
| _____________^
Expand All @@ -278,7 +296,7 @@ LL | | };
| |_____^ help: try: `res.map_or(1, |a| a + 1)`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:259:13
--> tests/ui/option_if_let_else.rs:275:13
|
LL | let _ = match res {
| _____________^
Expand All @@ -289,13 +307,13 @@ LL | | };
| |_____^ help: try: `res.map_or(1, |a| a + 1)`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:264:13
--> tests/ui/option_if_let_else.rs:280:13
|
LL | let _ = if let Ok(a) = res { a + 1 } else { 5 };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `res.map_or(5, |a| a + 1)`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:282:17
--> tests/ui/option_if_let_else.rs:298:17
|
LL | let _ = match initial {
| _________________^
Expand All @@ -306,7 +324,7 @@ LL | | };
| |_________^ help: try: `initial.as_ref().map_or(42, |value| do_something(value))`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:290:17
--> tests/ui/option_if_let_else.rs:306:17
|
LL | let _ = match initial {
| _________________^
Expand All @@ -317,7 +335,7 @@ LL | | };
| |_________^ help: try: `initial.as_mut().map_or(42, |value| do_something2(value))`

error: use Option::map_or_else instead of an if let/else
--> tests/ui/option_if_let_else.rs:314:24
--> tests/ui/option_if_let_else.rs:330:24
|
LL | let mut _hashmap = if let Some(hm) = &opt {
| ________________________^
Expand All @@ -329,19 +347,19 @@ LL | | };
| |_____^ help: try: `opt.as_ref().map_or_else(HashMap::new, |hm| hm.clone())`

error: use Option::map_or_else instead of an if let/else
--> tests/ui/option_if_let_else.rs:321:19
--> tests/ui/option_if_let_else.rs:337:19
|
LL | let mut _hm = if let Some(hm) = &opt { hm.clone() } else { new_map!() };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `opt.as_ref().map_or_else(|| new_map!(), |hm| hm.clone())`

error: use Option::map_or instead of an if let/else
--> tests/ui/option_if_let_else.rs:372:22
--> tests/ui/option_if_let_else.rs:388:22
|
LL | let _ = unsafe { if let Some(o) = *opt_raw_ptr { o } else { 1 } };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `(*opt_raw_ptr).map_or(1, |o| o)`

error: use Option::map_or_else instead of an if let/else
--> tests/ui/option_if_let_else.rs:378:13
--> tests/ui/option_if_let_else.rs:394:13
|
LL | let _ = match res {
| _____________^
Expand All @@ -351,5 +369,5 @@ LL | | Err(_) => String::new(),
LL | | };
| |_____^ help: try: `res.map_or_else(|_| String::new(), |s| s.clone())`

error: aborting due to 27 previous errors
error: aborting due to 29 previous errors