1 files changed, 170 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/try_err.fixed b/src/tools/clippy/tests/ui/try_err.fixed
new file mode 100644
index 000000000..264194419
--- /dev/null
+++ b/src/tools/clippy/tests/ui/try_err.fixed
@@ -0,0 +1,170 @@
+// run-rustfix
+// aux-build:macro_rules.rs
+
+#![deny(clippy::try_err)]
+#![allow(clippy::unnecessary_wraps, clippy::needless_question_mark)]
+
+#[macro_use]
+extern crate macro_rules;
+
+use std::io;
+use std::task::Poll;
+
+// Tests that a simple case works
+// Should flag `Err(err)?`
+pub fn basic_test() -> Result<i32, i32> {
+    let err: i32 = 1;
+    // To avoid warnings during rustfix
+    if true {
+        return Err(err);
+    }
+    Ok(0)
+}
+
+// Tests that `.into()` is added when appropriate
+pub fn into_test() -> Result<i32, i32> {
+    let err: u8 = 1;
+    // To avoid warnings during rustfix
+    if true {
+        return Err(err.into());
+    }
+    Ok(0)
+}
+
+// Tests that tries in general don't trigger the error
+pub fn negative_test() -> Result<i32, i32> {
+    Ok(nested_error()? + 1)
+}
+
+// Tests that `.into()` isn't added when the error type
+// matches the surrounding closure's return type, even
+// when it doesn't match the surrounding function's.
+pub fn closure_matches_test() -> Result<i32, i32> {
+    let res: Result<i32, i8> = Some(1)
+        .into_iter()
+        .map(|i| {
+            let err: i8 = 1;
+            // To avoid warnings during rustfix
+            if true {
+                return Err(err);
+            }
+            Ok(i)
+        })
+        .next()
+        .unwrap();
+
+    Ok(res?)
+}
+
+// Tests that `.into()` isn't added when the error type
+// doesn't match the surrounding closure's return type.
+pub fn closure_into_test() -> Result<i32, i32> {
+    let res: Result<i32, i16> = Some(1)
+        .into_iter()
+        .map(|i| {
+            let err: i8 = 1;
+            // To avoid warnings during rustfix
+            if true {
+                return Err(err.into());
+            }
+            Ok(i)
+        })
+        .next()
+        .unwrap();
+
+    Ok(res?)
+}
+
+fn nested_error() -> Result<i32, i32> {
+    Ok(1)
+}
+
+// Bad suggestion when in macro (see #6242)
+macro_rules! try_validation {
+    ($e: expr) => {{
+        match $e {
+            Ok(_) => 0,
+            Err(_) => return Err(1),
+        }
+    }};
+}
+
+macro_rules! ret_one {
+    () => {
+        1
+    };
+}
+
+macro_rules! try_validation_in_macro {
+    ($e: expr) => {{
+        match $e {
+            Ok(_) => 0,
+            Err(_) => return Err(ret_one!()),
+        }
+    }};
+}
+
+fn calling_macro() -> Result<i32, i32> {
+    // macro
+    try_validation!(Ok::<_, i32>(5));
+    // `Err` arg is another macro
+    try_validation_in_macro!(Ok::<_, i32>(5));
+    Ok(5)
+}
+
+fn main() {
+    basic_test().unwrap();
+    into_test().unwrap();
+    negative_test().unwrap();
+    closure_matches_test().unwrap();
+    closure_into_test().unwrap();
+    calling_macro().unwrap();
+
+    // We don't want to lint in external macros
+    try_err!();
+}
+
+macro_rules! bar {
+    () => {
+        String::from("aasdfasdfasdfa")
+    };
+}
+
+macro_rules! foo {
+    () => {
+        bar!()
+    };
+}
+
+pub fn macro_inside(fail: bool) -> Result<i32, String> {
+    if fail {
+        return Err(foo!());
+    }
+    Ok(0)
+}
+
+pub fn poll_write(n: usize) -> Poll<io::Result<usize>> {
+    if n == 0 {
+        return Poll::Ready(Err(io::ErrorKind::WriteZero.into()))
+    } else if n == 1 {
+        return Poll::Ready(Err(io::Error::new(io::ErrorKind::InvalidInput, "error")))
+    };
+
+    Poll::Ready(Ok(n))
+}
+
+pub fn poll_next(ready: bool) -> Poll<Option<io::Result<()>>> {
+    if !ready {
+        return Poll::Ready(Some(Err(io::ErrorKind::NotFound.into())))
+    }
+
+    Poll::Ready(None)
+}
+
+// Tests that `return` is not duplicated
+pub fn try_return(x: bool) -> Result<i32, i32> {
+    if x {
+        return Err(42);
+    }
+    Ok(0)
+}