1 files changed, 43 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 000000000..43d71c2e8
--- /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(())
+}