diff options
| -rw-r--r-- | src/test/ui/lint/for_loop_over_fallibles.rs | 43 | ||||
| -rw-r--r-- | src/test/ui/lint/for_loop_over_fallibles.stderr | 102 |
2 files changed, 145 insertions, 0 deletions
diff --git a/src/test/ui/lint/for_loop_over_fallibles.rs b/src/test/ui/lint/for_loop_over_fallibles.rs new file mode 100644 index 00000000000..43d71c2e808 --- /dev/null +++ b/src/test/ui/lint/for_loop_over_fallibles.rs @@ -0,0 +1,43 @@ +// check-pass + +fn main() { + // Common + for _ in Some(1) {} + //~^ WARN for loop over an `Option`. This is more readably written as an `if let` statement + //~| HELP to check pattern in a loop use `while let` + //~| HELP consider using `if let` to clear intent + for _ in Ok::<_, ()>(1) {} + //~^ WARN for loop over a `Result`. This is more readably written as an `if let` statement + //~| HELP to check pattern in a loop use `while let` + //~| HELP consider using `if let` to clear intent + + // `Iterator::next` specific + for _ in [0; 0].iter().next() {} + //~^ WARN for loop over an `Option`. This is more readably written as an `if let` statement + //~| HELP to iterate over `[0; 0].iter()` remove the call to `next` + //~| HELP consider using `if let` to clear intent + + // `Result<impl Iterator, _>`, but function doesn't return `Result` + for _ in Ok::<_, ()>([0; 0].iter()) {} + //~^ WARN for loop over a `Result`. This is more readably written as an `if let` statement + //~| HELP to check pattern in a loop use `while let` + //~| HELP consider using `if let` to clear intent +} + +fn _returns_result() -> Result<(), ()> { + // `Result<impl Iterator, _>` + for _ in Ok::<_, ()>([0; 0].iter()) {} + //~^ WARN for loop over a `Result`. This is more readably written as an `if let` statement + //~| HELP to check pattern in a loop use `while let` + //~| HELP consider unwrapping the `Result` with `?` to iterate over its contents + //~| HELP consider using `if let` to clear intent + + // `Result<impl IntoIterator>` + for _ in Ok::<_, ()>([0; 0]) {} + //~^ WARN for loop over a `Result`. This is more readably written as an `if let` statement + //~| HELP to check pattern in a loop use `while let` + //~| HELP consider unwrapping the `Result` with `?` to iterate over its contents + //~| HELP consider using `if let` to clear intent + + Ok(()) +} diff --git a/src/test/ui/lint/for_loop_over_fallibles.stderr b/src/test/ui/lint/for_loop_over_fallibles.stderr new file mode 100644 index 00000000000..52eac945d85 --- /dev/null +++ b/src/test/ui/lint/for_loop_over_fallibles.stderr @@ -0,0 +1,102 @@ +warning: for loop over an `Option`. This is more readably written as an `if let` statement + --> $DIR/for_loop_over_fallibles.rs:5:14 + | +LL | for _ in Some(1) {} + | ^^^^^^^ + | + = note: `#[warn(for_loop_over_fallibles)]` on by default +help: to check pattern in a loop use `while let` + | +LL | while let Some(_) = Some(1) {} + | ~~~~~~~~~~~~~~~ ~~~ +help: consider using `if let` to clear intent + | +LL | if let Some(_) = Some(1) {} + | ~~~~~~~~~~~~ ~~~ + +warning: for loop over a `Result`. This is more readably written as an `if let` statement + --> $DIR/for_loop_over_fallibles.rs:9:14 + | +LL | for _ in Ok::<_, ()>(1) {} + | ^^^^^^^^^^^^^^ + | +help: to check pattern in a loop use `while let` + | +LL | while let Ok(_) = Ok::<_, ()>(1) {} + | ~~~~~~~~~~~~~ ~~~ +help: consider using `if let` to clear intent + | +LL | if let Ok(_) = Ok::<_, ()>(1) {} + | ~~~~~~~~~~ ~~~ + +warning: for loop over an `Option`. This is more readably written as an `if let` statement + --> $DIR/for_loop_over_fallibles.rs:15:14 + | +LL | for _ in [0; 0].iter().next() {} + | ^^^^^^^^^^^^^^^^^^^^ + | +help: to iterate over `[0; 0].iter()` remove the call to `next` + | +LL - for _ in [0; 0].iter().next() {} +LL + for _ in [0; 0].iter() {} + | +help: consider using `if let` to clear intent + | +LL | if let Some(_) = [0; 0].iter().next() {} + | ~~~~~~~~~~~~ ~~~ + +warning: for loop over a `Result`. This is more readably written as an `if let` statement + --> $DIR/for_loop_over_fallibles.rs:21:14 + | +LL | for _ in Ok::<_, ()>([0; 0].iter()) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: to check pattern in a loop use `while let` + | +LL | while let Ok(_) = Ok::<_, ()>([0; 0].iter()) {} + | ~~~~~~~~~~~~~ ~~~ +help: consider using `if let` to clear intent + | +LL | if let Ok(_) = Ok::<_, ()>([0; 0].iter()) {} + | ~~~~~~~~~~ ~~~ + +warning: for loop over a `Result`. This is more readably written as an `if let` statement + --> $DIR/for_loop_over_fallibles.rs:29:14 + | +LL | for _ in Ok::<_, ()>([0; 0].iter()) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: to check pattern in a loop use `while let` + | +LL | while let Ok(_) = Ok::<_, ()>([0; 0].iter()) {} + | ~~~~~~~~~~~~~ ~~~ +help: consider unwrapping the `Result` with `?` to iterate over its contents + | +LL | for _ in Ok::<_, ()>([0; 0].iter())? {} + | + +help: consider using `if let` to clear intent + | +LL | if let Ok(_) = Ok::<_, ()>([0; 0].iter()) {} + | ~~~~~~~~~~ ~~~ + +warning: for loop over a `Result`. This is more readably written as an `if let` statement + --> $DIR/for_loop_over_fallibles.rs:36:14 + | +LL | for _ in Ok::<_, ()>([0; 0]) {} + | ^^^^^^^^^^^^^^^^^^^ + | +help: to check pattern in a loop use `while let` + | +LL | while let Ok(_) = Ok::<_, ()>([0; 0]) {} + | ~~~~~~~~~~~~~ ~~~ +help: consider unwrapping the `Result` with `?` to iterate over its contents + | +LL | for _ in Ok::<_, ()>([0; 0])? {} + | + +help: consider using `if let` to clear intent + | +LL | if let Ok(_) = Ok::<_, ()>([0; 0]) {} + | ~~~~~~~~~~ ~~~ + +warning: 6 warnings emitted + |