Auto merge of rust-lang#5108 - JohnTitor:split-up-0130, r=flip1995

Split up `match` ui test

Part of rust-lang#2038

Also, this decreases the line length limit to 220.

changelog: none

Author: bors

clippy_dev/src/stderr_length_check.rs

@@ -7,7 +7,7 @@ use std::io::prelude::*;
 // The maximum length allowed for stderr files.
 //
 // We limit this because small files are easier to deal with than bigger files.
-const LIMIT: usize = 245;
+const LIMIT: usize = 220;
 
 pub fn check() {
     let stderr_files = stderr_files();

tests/ui/match_same_arms2.rs

@@ -79,6 +79,46 @@ fn match_same_arms() {
         (None, Some(a)) => bar(a), // bindings have different types
         _ => (),
     }
+
+    let x: Result<i32, &str> = Ok(3);
+
+    // No warning because of the guard.
+    match x {
+        Ok(x) if x * x == 64 => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_) => println!("err"),
+    }
+
+    // This used to be a false positive; see issue #1996.
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(x) if x * x == 64 => println!("ok 64"),
+        Ok(_) => println!("ok"),
+        Err(_) => println!("err"),
+    }
+
+    match (x, Some(1i32)) {
+        (Ok(x), Some(_)) => println!("ok {}", x),
+        (Ok(_), Some(x)) => println!("ok {}", x),
+        _ => println!("err"),
+    }
+
+    // No warning; different types for `x`.
+    match (x, Some(1.0f64)) {
+        (Ok(x), Some(_)) => println!("ok {}", x),
+        (Ok(_), Some(x)) => println!("ok {}", x),
+        _ => println!("err"),
+    }
+
+    // False negative #2251.
+    match x {
+        Ok(_tmp) => println!("ok"),
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_) => {
+            unreachable!();
+        },
+    }
 }
 
 fn main() {}

tests/ui/match_same_arms2.stderr

@@ -105,5 +105,41 @@ help: consider refactoring into `(Some(a), ..) | (.., Some(a))`
 LL |         (Some(a), ..) => bar(a),
    |         ^^^^^^^^^^^^^
 
-error: aborting due to 5 previous errors
+error: this `match` has identical arm bodies
+  --> $DIR/match_same_arms2.rs:102:29
+   |
+LL |         (Ok(_), Some(x)) => println!("ok {}", x),
+   |                             ^^^^^^^^^^^^^^^^^^^^
+   |
+note: same as this
+  --> $DIR/match_same_arms2.rs:101:29
+   |
+LL |         (Ok(x), Some(_)) => println!("ok {}", x),
+   |                             ^^^^^^^^^^^^^^^^^^^^
+help: consider refactoring into `(Ok(x), Some(_)) | (Ok(_), Some(x))`
+  --> $DIR/match_same_arms2.rs:101:9
+   |
+LL |         (Ok(x), Some(_)) => println!("ok {}", x),
+   |         ^^^^^^^^^^^^^^^^
+   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
+
+error: this `match` has identical arm bodies
+  --> $DIR/match_same_arms2.rs:117:18
+   |
+LL |         Ok(_) => println!("ok"),
+   |                  ^^^^^^^^^^^^^^
+   |
+note: same as this
+  --> $DIR/match_same_arms2.rs:116:18
+   |
+LL |         Ok(3) => println!("ok"),
+   |                  ^^^^^^^^^^^^^^
+help: consider refactoring into `Ok(3) | Ok(_)`
+  --> $DIR/match_same_arms2.rs:116:9
+   |
+LL |         Ok(3) => println!("ok"),
+   |         ^^^^^
+   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
+
+error: aborting due to 7 previous errors
 

tests/ui/match_wild_err_arm.rs

@@ -0,0 +1,65 @@
+#![feature(exclusive_range_pattern)]
+#![allow(clippy::match_same_arms)]
+#![warn(clippy::match_wild_err_arm)]
+
+fn match_wild_err_arm() {
+    let x: Result<i32, &str> = Ok(3);
+
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_) => panic!("err"),
+    }
+
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_) => panic!(),
+    }
+
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_) => {
+            panic!();
+        },
+    }
+
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_e) => panic!(),
+    }
+
+    // Allowed when used in `panic!`.
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_e) => panic!("{}", _e),
+    }
+
+    // Allowed when not with `panic!` block.
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_) => println!("err"),
+    }
+
+    // Allowed when used with `unreachable!`.
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_) => unreachable!(),
+    }
+
+    // Allowed when used with `unreachable!`.
+    match x {
+        Ok(3) => println!("ok"),
+        Ok(_) => println!("ok"),
+        Err(_) => {
+            unreachable!();
+        },
+    }
+}
+
+fn main() {}

tests/ui/match_wild_err_arm.stderr

@@ -0,0 +1,35 @@
+error: `Err(_)` matches all errors
+  --> $DIR/match_wild_err_arm.rs:11:9
+   |
+LL |         Err(_) => panic!("err"),
+   |         ^^^^^^
+   |
+   = note: `-D clippy::match-wild-err-arm` implied by `-D warnings`
+   = note: match each error separately or use the error output
+
+error: `Err(_)` matches all errors
+  --> $DIR/match_wild_err_arm.rs:17:9
+   |
+LL |         Err(_) => panic!(),
+   |         ^^^^^^
+   |
+   = note: match each error separately or use the error output
+
+error: `Err(_)` matches all errors
+  --> $DIR/match_wild_err_arm.rs:23:9
+   |
+LL |         Err(_) => {
+   |         ^^^^^^
+   |
+   = note: match each error separately or use the error output
+
+error: `Err(_e)` matches all errors
+  --> $DIR/match_wild_err_arm.rs:31:9
+   |
+LL |         Err(_e) => panic!(),
+   |         ^^^^^^^
+   |
+   = note: match each error separately or use the error output
+
+error: aborting due to 4 previous errors
+