New upstream version 1.52.1+dfsg1

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

diff --git a/src/tools/clippy/tests/ui/map_identity.rs b/src/tools/clippy/tests/ui/map_identity.rs
new file mode 100644 (file)
index 0000000..65c7e6e
--- /dev/null
+++ b/src/tools/clippy/tests/ui/map_identity.rs
@@ -0,0 +1,25 @@
+// run-rustfix
+#![warn(clippy::map_identity)]
+#![allow(clippy::needless_return)]
+
+fn main() {
+    let x: [u16; 3] = [1, 2, 3];
+    // should lint
+    let _: Vec<_> = x.iter().map(not_identity).map(|x| return x).collect();
+    let _: Vec<_> = x.iter().map(std::convert::identity).map(|y| y).collect();
+    let _: Option<u8> = Some(3).map(|x| x);
+    let _: Result<i8, f32> = Ok(-3).map(|x| {
+        return x;
+    });
+    // should not lint
+    let _: Vec<_> = x.iter().map(|x| 2 * x).collect();
+    let _: Vec<_> = x.iter().map(not_identity).map(|x| return x - 4).collect();
+    let _: Option<u8> = None.map(|x: u8| x - 1);
+    let _: Result<i8, f32> = Err(2.3).map(|x: i8| {
+        return x + 3;
+    });
+}
+
+fn not_identity(x: &u16) -> u16 {
+    *x
+}