Update upstream source from tag 'upstream/1.52.1+dfsg1'

[rustc.git] / src / tools / clippy / tests / ui / redundant_pattern_matching_result.rs

diff --git a/src/tools/clippy/tests/ui/redundant_pattern_matching_result.rs b/src/tools/clippy/tests/ui/redundant_pattern_matching_result.rs
new file mode 100644 (file)
index 0000000..5d17529
--- /dev/null
+++ b/src/tools/clippy/tests/ui/redundant_pattern_matching_result.rs
@@ -0,0 +1,127 @@
+// run-rustfix
+
+#![warn(clippy::all)]
+#![warn(clippy::redundant_pattern_matching)]
+#![allow(
+    unused_must_use,
+    clippy::needless_bool,
+    clippy::match_like_matches_macro,
+    clippy::unnecessary_wraps,
+    deprecated
+)]
+
+fn main() {
+    let result: Result<usize, usize> = Err(5);
+    if let Ok(_) = &result {}
+
+    if let Ok(_) = Ok::<i32, i32>(42) {}
+
+    if let Err(_) = Err::<i32, i32>(42) {}
+
+    while let Ok(_) = Ok::<i32, i32>(10) {}
+
+    while let Err(_) = Ok::<i32, i32>(10) {}
+
+    if Ok::<i32, i32>(42).is_ok() {}
+
+    if Err::<i32, i32>(42).is_err() {}
+
+    if let Ok(x) = Ok::<i32, i32>(42) {
+        println!("{}", x);
+    }
+
+    match Ok::<i32, i32>(42) {
+        Ok(_) => true,
+        Err(_) => false,
+    };
+
+    match Ok::<i32, i32>(42) {
+        Ok(_) => false,
+        Err(_) => true,
+    };
+
+    match Err::<i32, i32>(42) {
+        Ok(_) => false,
+        Err(_) => true,
+    };
+
+    match Err::<i32, i32>(42) {
+        Ok(_) => true,
+        Err(_) => false,
+    };
+
+    let _ = if let Ok(_) = Ok::<usize, ()>(4) { true } else { false };
+
+    issue5504();
+    issue6067();
+    issue6065();
+
+    let _ = if let Ok(_) = gen_res() {
+        1
+    } else if let Err(_) = gen_res() {
+        2
+    } else {
+        3
+    };
+}
+
+fn gen_res() -> Result<(), ()> {
+    Ok(())
+}
+
+macro_rules! m {
+    () => {
+        Some(42u32)
+    };
+}
+
+fn issue5504() {
+    fn result_opt() -> Result<Option<i32>, i32> {
+        Err(42)
+    }
+
+    fn try_result_opt() -> Result<i32, i32> {
+        while let Some(_) = r#try!(result_opt()) {}
+        if let Some(_) = r#try!(result_opt()) {}
+        Ok(42)
+    }
+
+    try_result_opt();
+
+    if let Some(_) = m!() {}
+    while let Some(_) = m!() {}
+}
+
+fn issue6065() {
+    macro_rules! if_let_in_macro {
+        ($pat:pat, $x:expr) => {
+            if let Some($pat) = $x {}
+        };
+    }
+
+    // shouldn't be linted
+    if_let_in_macro!(_, Some(42));
+}
+
+// Methods that are unstable const should not be suggested within a const context, see issue #5697.
+// However, in Rust 1.48.0 the methods `is_ok` and `is_err` of `Result` were stabilized as const,
+// so the following should be linted.
+const fn issue6067() {
+    if let Ok(_) = Ok::<i32, i32>(42) {}
+
+    if let Err(_) = Err::<i32, i32>(42) {}
+
+    while let Ok(_) = Ok::<i32, i32>(10) {}
+
+    while let Err(_) = Ok::<i32, i32>(10) {}
+
+    match Ok::<i32, i32>(42) {
+        Ok(_) => true,
+        Err(_) => false,
+    };
+
+    match Err::<i32, i32>(42) {
+        Ok(_) => false,
+        Err(_) => true,
+    };
+}