Add regression test for manual_is_variant_and extension

Author: GuillaumeGomez

tests/ui/manual_is_variant_and2.fixed

@@ -0,0 +1,45 @@
+#![warn(clippy::manual_is_variant_and)]
+
+struct Foo<T>(T);
+
+impl<T> Foo<T> {
+    fn map<F: FnMut(T) -> bool>(self, mut f: F) -> Option<bool> {
+        Some(f(self.0))
+    }
+}
+
+fn foo() -> Option<bool> {
+    Some(true)
+}
+
+macro_rules! some_true {
+    () => {
+        Some(true)
+    };
+}
+macro_rules! some_false {
+    () => {
+        Some(false)
+    };
+}
+
+fn main() {
+    let _ = Some(2).is_some_and(|x| x % 2 == 0);
+    //~^ manual_is_variant_and
+    let _ = Some(2).is_none_or(|x| x % 2 == 0);
+    //~^ manual_is_variant_and
+    let _ = Some(2).is_some_and(|x| x % 2 == 0);
+    //~^ manual_is_variant_and
+    let _ = Some(2).is_none_or(|x| x % 2 == 0);
+    //~^ manual_is_variant_and
+    let _ = Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0);
+    //~^ manual_is_variant_and
+    let _ = !Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0);
+    //~^ manual_is_variant_and
+    let _ = !Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0);
+    //~^ manual_is_variant_and
+
+    // Should not lint.
+    let _ = Foo::<u32>(0).map(|x| x % 2 == 0) == Some(true);
+    let _ = Some(2).map(|x| x % 2 == 0) != foo();
+}

tests/ui/manual_is_variant_and2.rs

@@ -0,0 +1,45 @@
+#![warn(clippy::manual_is_variant_and)]
+
+struct Foo<T>(T);
+
+impl<T> Foo<T> {
+    fn map<F: FnMut(T) -> bool>(self, mut f: F) -> Option<bool> {
+        Some(f(self.0))
+    }
+}
+
+fn foo() -> Option<bool> {
+    Some(true)
+}
+
+macro_rules! some_true {
+    () => {
+        Some(true)
+    };
+}
+macro_rules! some_false {
+    () => {
+        Some(false)
+    };
+}
+
+fn main() {
+    let _ = Some(2).map(|x| x % 2 == 0) == Some(true);
+    //~^ manual_is_variant_and
+    let _ = Some(2).map(|x| x % 2 == 0) != Some(true);
+    //~^ manual_is_variant_and
+    let _ = Some(2).map(|x| x % 2 == 0) == some_true!();
+    //~^ manual_is_variant_and
+    let _ = Some(2).map(|x| x % 2 == 0) != some_false!();
+    //~^ manual_is_variant_and
+    let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) == Ok(true);
+    //~^ manual_is_variant_and
+    let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) != Ok(true);
+    //~^ manual_is_variant_and
+    let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) != Ok(true);
+    //~^ manual_is_variant_and
+
+    // Should not lint.
+    let _ = Foo::<u32>(0).map(|x| x % 2 == 0) == Some(true);
+    let _ = Some(2).map(|x| x % 2 == 0) != foo();
+}

tests/ui/manual_is_variant_and2.stderr

@@ -0,0 +1,47 @@
+error: called `.map() == Some()`
+  --> tests/ui/manual_is_variant_and2.rs:27:13
+   |
+LL |     let _ = Some(2).map(|x| x % 2 == 0) == Some(true);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Some(2).is_some_and(|x| x % 2 == 0)`
+   |
+   = note: `-D clippy::manual-is-variant-and` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::manual_is_variant_and)]`
+
+error: called `.map() != Some()`
+  --> tests/ui/manual_is_variant_and2.rs:29:13
+   |
+LL |     let _ = Some(2).map(|x| x % 2 == 0) != Some(true);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Some(2).is_none_or(|x| x % 2 == 0)`
+
+error: called `.map() == Some()`
+  --> tests/ui/manual_is_variant_and2.rs:31:13
+   |
+LL |     let _ = Some(2).map(|x| x % 2 == 0) == some_true!();
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Some(2).is_some_and(|x| x % 2 == 0)`
+
+error: called `.map() != Some()`
+  --> tests/ui/manual_is_variant_and2.rs:33:13
+   |
+LL |     let _ = Some(2).map(|x| x % 2 == 0) != some_false!();
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Some(2).is_none_or(|x| x % 2 == 0)`
+
+error: called `.map() == Ok()`
+  --> tests/ui/manual_is_variant_and2.rs:35:13
+   |
+LL |     let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) == Ok(true);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0)`
+
+error: called `.map() != Ok()`
+  --> tests/ui/manual_is_variant_and2.rs:37:13
+   |
+LL |     let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) != Ok(true);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `!Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0)`
+
+error: called `.map() != Ok()`
+  --> tests/ui/manual_is_variant_and2.rs:39:13
+   |
+LL |     let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) != Ok(true);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `!Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0)`
+
+error: aborting due to 7 previous errors
+