Add more testcases for redundant_pattern_matching

These should make sure that, when the suggestions are fixed, they are
fixed for all these cases.

tests/ui/redundant_pattern_matching.rs

@@ -51,4 +51,30 @@ fn main() {
         Some(_) => false,
         None => true,
     };
+
+    let _ = match None::<()> {
+        Some(_) => false,
+        None => true,
+    };
+
+    let _ = if let Ok(_) = Ok::<usize, ()>(4) { true } else { false };
+
+    let _ = does_something();
+    let _ = returns_unit();
+}
+
+fn does_something() -> bool {
+    if let Ok(_) = Ok::<i32, i32>(4) {
+        true
+    } else {
+        false
+    }
+}
+
+fn returns_unit() {
+    if let Ok(_) = Ok::<i32, i32>(4) {
+        true
+    } else {
+        false
+    };
 }

tests/ui/redundant_pattern_matching.stderr

@@ -1,5 +1,5 @@
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:5:12
+  --> $DIR/redundant_pattern_matching.rs:6:12
    |
 LL |     if let Ok(_) = Ok::<i32, i32>(42) {}
    |     -------^^^^^------------------------ help: try this: `Ok::<i32, i32>(42).is_ok()`
@@ -7,25 +7,25 @@ LL |     if let Ok(_) = Ok::<i32, i32>(42) {}
    = note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
 
 error: redundant pattern matching, consider using `is_err()`
-  --> $DIR/redundant_pattern_matching.rs:7:12
+  --> $DIR/redundant_pattern_matching.rs:8:12
    |
 LL |     if let Err(_) = Err::<i32, i32>(42) {}
    |     -------^^^^^^------------------------- help: try this: `Err::<i32, i32>(42).is_err()`
 
 error: redundant pattern matching, consider using `is_none()`
-  --> $DIR/redundant_pattern_matching.rs:9:12
+  --> $DIR/redundant_pattern_matching.rs:10:12
    |
 LL |     if let None = None::<()> {}
    |     -------^^^^---------------- help: try this: `None::<()>.is_none()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:11:12
+  --> $DIR/redundant_pattern_matching.rs:12:12
    |
 LL |     if let Some(_) = Some(42) {}
    |     -------^^^^^^^-------------- help: try this: `Some(42).is_some()`
 
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:25:5
+  --> $DIR/redundant_pattern_matching.rs:26:5
    |
 LL | /     match Ok::<i32, i32>(42) {
 LL | |         Ok(_) => true,
@@ -34,7 +34,7 @@ LL | |     };
    | |_____^ help: try this: `Ok::<i32, i32>(42).is_ok()`
 
 error: redundant pattern matching, consider using `is_err()`
-  --> $DIR/redundant_pattern_matching.rs:30:5
+  --> $DIR/redundant_pattern_matching.rs:31:5
    |
 LL | /     match Ok::<i32, i32>(42) {
 LL | |         Ok(_) => false,
@@ -43,7 +43,7 @@ LL | |     };
    | |_____^ help: try this: `Ok::<i32, i32>(42).is_err()`
 
 error: redundant pattern matching, consider using `is_err()`
-  --> $DIR/redundant_pattern_matching.rs:35:5
+  --> $DIR/redundant_pattern_matching.rs:36:5
    |
 LL | /     match Err::<i32, i32>(42) {
 LL | |         Ok(_) => false,
@@ -52,7 +52,7 @@ LL | |     };
    | |_____^ help: try this: `Err::<i32, i32>(42).is_err()`
 
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:40:5
+  --> $DIR/redundant_pattern_matching.rs:41:5
    |
 LL | /     match Err::<i32, i32>(42) {
 LL | |         Ok(_) => true,
@@ -61,7 +61,7 @@ LL | |     };
    | |_____^ help: try this: `Err::<i32, i32>(42).is_ok()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:45:5
+  --> $DIR/redundant_pattern_matching.rs:46:5
    |
 LL | /     match Some(42) {
 LL | |         Some(_) => true,
@@ -70,7 +70,7 @@ LL | |     };
    | |_____^ help: try this: `Some(42).is_some()`
 
 error: redundant pattern matching, consider using `is_none()`
-  --> $DIR/redundant_pattern_matching.rs:50:5
+  --> $DIR/redundant_pattern_matching.rs:51:5
    |
 LL | /     match None::<()> {
 LL | |         Some(_) => false,
@@ -78,5 +78,51 @@ LL | |         None => true,
 LL | |     };
    | |_____^ help: try this: `None::<()>.is_none()`
 
-error: aborting due to 10 previous errors
+error: redundant pattern matching, consider using `is_none()`
+  --> $DIR/redundant_pattern_matching.rs:56:15
+   |
+LL |       let foo = match None::<()> {
+   |  _______________^
+LL | |         Some(_) => false,
+LL | |         None => true,
+LL | |     };
+   | |_____^ help: try this: `None::<()>.is_none()`
+
+error: redundant pattern matching, consider using `is_ok()`
+  --> $DIR/redundant_pattern_matching.rs:61:20
+   |
+LL |     let _ = if let Ok(_) = Ok::<usize, ()>(4) { true } else { false };
+   |             -------^^^^^--------------------------------------------- help: try this: `Ok::<usize, ()>(4).is_ok()`
+
+error: this let-binding has unit value
+  --> $DIR/redundant_pattern_matching.rs:64:5
+   |
+LL |     let _ = returns_unit();
+   |     ^^^^^^^^^^^^^^^^^^^^^^^ help: omit the `let` binding: `returns_unit();`
+   |
+   = note: `-D clippy::let-unit-value` implied by `-D warnings`
+
+error: redundant pattern matching, consider using `is_ok()`
+  --> $DIR/redundant_pattern_matching.rs:68:12
+   |
+LL |       if let Ok(_) = Ok::<i32, i32>(4) {
+   |  _____-      ^^^^^
+LL | |         true
+LL | |     } else {
+LL | |         false
+LL | |     }
+   | |_____- help: try this: `Ok::<i32, i32>(4).is_ok()`
+
+error: redundant pattern matching, consider using `is_ok()`
+  --> $DIR/redundant_pattern_matching.rs:76:12
+   |
+LL |       if let Ok(_) = Ok::<i32, i32>(4) {
+   |  _____-      ^^^^^
+LL | |         true
+LL | |     } else {
+LL | |         false
+LL | |     };
+   | |_____- help: try this: `Ok::<i32, i32>(4).is_ok()`
+
+error: aborting due to 15 previous errors