1 files changed, 98 insertions, 0 deletions
diff --git a/tests/project_replace.rs b/tests/project_replace.rs
new file mode 100644
index 0000000..9c8a5ab
--- /dev/null
+++ b/tests/project_replace.rs
@@ -0,0 +1,98 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+#![allow(dead_code)]
+
+use pin_project::{pin_project, project_replace};
+use std::{marker::PhantomData, pin::Pin};
+
+#[project_replace] // Nightly does not need a dummy attribute to the function.
+#[test]
+fn project_replace_stmt_expr() {
+    #[pin_project(Replace)]
+    struct Struct<T, U> {
+        #[pin]
+        field1: T,
+        field2: U,
+    }
+
+    let mut s = Struct { field1: 1, field2: 2 };
+
+    #[project_replace]
+    let Struct { field1, field2 } =
+        Pin::new(&mut s).project_replace(Struct { field1: 42, field2: 43 });
+
+    let _x: PhantomData<i32> = field1;
+
+    let y: i32 = field2;
+    assert_eq!(y, 2);
+
+    // tuple struct
+
+    #[pin_project(Replace)]
+    struct TupleStruct<T, U>(#[pin] T, U);
+
+    let mut s = TupleStruct(1, 2);
+
+    #[project_replace]
+    let TupleStruct(x, y) = Pin::new(&mut s).project_replace(TupleStruct(42, 43));
+
+    let _x: PhantomData<i32> = x;
+    let y: i32 = y;
+    assert_eq!(y, 2);
+
+    #[pin_project(Replace)]
+    enum Enum<A, B, C, D> {
+        Variant1(#[pin] A, B),
+        Variant2 {
+            #[pin]
+            field1: C,
+            field2: D,
+        },
+        None,
+    }
+
+    let mut e = Enum::Variant1(1, 2);
+
+    let e = Pin::new(&mut e).project_replace(Enum::None);
+
+    #[project_replace]
+    match e {
+        Enum::Variant1(x, y) => {
+            let _x: PhantomData<i32> = x;
+            let y: i32 = y;
+            assert_eq!(y, 2);
+        }
+        Enum::Variant2 { field1, field2 } => {
+            let _x: PhantomData<i32> = field1;
+            let _y: i32 = field2;
+            panic!()
+        }
+        Enum::None => panic!(),
+    }
+}
+
+#[project_replace]
+#[test]
+fn combine() {
+    #[pin_project(Replace)]
+    enum Enum<A> {
+        V1(#[pin] A),
+        V2,
+    }
+
+    let mut x = Enum::V1(1);
+    #[project]
+    match Pin::new(&mut x).project() {
+        Enum::V1(_) => {}
+        Enum::V2 => unreachable!(),
+    }
+    #[project_ref]
+    match Pin::new(&x).project_ref() {
+        Enum::V1(_) => {}
+        Enum::V2 => unreachable!(),
+    }
+    #[project_replace]
+    match Pin::new(&mut x).project_replace(Enum::V2) {
+        Enum::V1(_) => {}
+        Enum::V2 => unreachable!(),
+    }
+}