1 files changed, 186 insertions, 0 deletions
diff --git a/tests/ui/macros/rfc-2011-nicer-assert-messages/all-expr-kinds.rs b/tests/ui/macros/rfc-2011-nicer-assert-messages/all-expr-kinds.rs
new file mode 100644
index 00000000000..b8b6f0846bb
--- /dev/null
+++ b/tests/ui/macros/rfc-2011-nicer-assert-messages/all-expr-kinds.rs
@@ -0,0 +1,186 @@
+// edition:2021
+// ignore-tidy-linelength
+// only-x86_64
+// run-pass
+// needs-unwind Asserting on contents of error message
+
+#![allow(path_statements, unused_allocation)]
+#![feature(box_syntax, core_intrinsics, generic_assert, generic_assert_internals)]
+
+macro_rules! test {
+  (
+    let mut $elem_ident:ident = $elem_expr:expr;
+    [ $($assert:tt)* ] => $msg:literal
+  ) => {
+    {
+      #[allow(unused_assignments, unused_mut, unused_variables)]
+      let rslt = std::panic::catch_unwind(|| {
+        let mut $elem_ident = $elem_expr;
+        assert!($($assert)*);
+      });
+      let err = rslt.unwrap_err();
+      if let Some(elem) = err.downcast_ref::<String>() {
+        assert_eq!(elem, &$msg);
+      }
+      else if let Some(elem) = err.downcast_ref::<&str>() {
+        assert_eq!(elem, &$msg);
+      }
+      else {
+        panic!("assert!( ... ) should return a string");
+      }
+    }
+  }
+}
+
+macro_rules! tests {
+  (
+    let mut $elem_ident:ident = $elem_expr:expr;
+
+    $(
+      [ $($elem_assert:tt)* ] => $elem_msg:literal
+    )+
+  ) => {
+    $(
+      test!(
+        let mut $elem_ident = $elem_expr;
+        [ $($elem_assert)* ] => $elem_msg
+      );
+    )+
+  }
+}
+
+const FOO: Foo = Foo { bar: 1 };
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+struct Foo {
+  bar: i32
+}
+
+impl Foo {
+  fn add(&self, a: i32, b: i32) -> i32 { a + b }
+}
+
+fn add(a: i32, b: i32) -> i32 { a + b }
+
+fn main() {
+  // ***** Allowed *****
+
+  tests!(
+    let mut elem = 1i32;
+
+    // addr of
+    [ &elem == &3 ] => "Assertion failed: &elem == &3\nWith captures:\n  elem = 1\n"
+
+    // array
+    [ [elem][0] == 3 ] => "Assertion failed: [elem][0] == 3\nWith captures:\n  elem = 1\n"
+
+    // binary
+    [ elem + 1 == 3 ] => "Assertion failed: elem + 1 == 3\nWith captures:\n  elem = 1\n"
+
+    // call
+    [ add(elem, elem) == 3 ] => "Assertion failed: add(elem, elem) == 3\nWith captures:\n  elem = 1\n"
+
+    // cast
+    [ elem as i32 == 3 ] => "Assertion failed: elem as i32 == 3\nWith captures:\n  elem = 1\n"
+
+    // index
+    [ [1i32, 1][elem as usize] == 3 ] => "Assertion failed: [1i32, 1][elem as usize] == 3\nWith captures:\n  elem = 1\n"
+
+    // method call
+    [ FOO.add(elem, elem) == 3 ] => "Assertion failed: FOO.add(elem, elem) == 3\nWith captures:\n  elem = 1\n"
+
+    // paren
+    [ (elem) == 3 ] => "Assertion failed: (elem) == 3\nWith captures:\n  elem = 1\n"
+
+    // range
+    [ (0..elem) == (0..3) ] => "Assertion failed: (0..elem) == (0..3)\nWith captures:\n  elem = 1\n"
+
+    // repeat
+    [ [elem; 1] == [3; 1] ] => "Assertion failed: [elem; 1] == [3; 1]\nWith captures:\n  elem = 1\n"
+
+    // struct
+    [ Foo { bar: elem } == Foo { bar: 3 } ] => "Assertion failed: Foo { bar: elem } == Foo { bar: 3 }\nWith captures:\n  elem = 1\n"
+
+    // tuple
+    [ (elem, 1) == (3, 3) ] => "Assertion failed: (elem, 1) == (3, 3)\nWith captures:\n  elem = 1\n"
+
+    // unary
+    [ -elem == -3 ] => "Assertion failed: -elem == -3\nWith captures:\n  elem = 1\n"
+  );
+
+  // ***** Disallowed *****
+
+  tests!(
+    let mut elem = 1i32;
+
+    // assign
+    [ { let local = elem; local } == 3 ] => "Assertion failed: { let local = elem; local } == 3"
+
+    // assign op
+    [ { elem += 1; elem } == 3 ] => "Assertion failed: { elem += 1; elem } == 3"
+
+    // async
+    [ { let _ = async { elem }; elem } == 3 ] => "Assertion failed: { let _ = async { elem }; elem } == 3"
+
+    // await
+
+    // block
+    [ { elem } == 3 ] => "Assertion failed: { elem } == 3"
+
+    // box
+    [ box elem == box 3 ] => "Assertion failed: box elem == box 3"
+
+    // break
+    [ loop { break elem; } ==  3 ] => "Assertion failed: loop { break elem; } == 3"
+
+    // closure
+    [(|| elem)() ==  3 ] => "Assertion failed: (|| elem)() == 3"
+
+    // const block
+
+    // continue
+
+    // err
+
+    // field
+    [ FOO.bar ==  3 ] => "Assertion failed: FOO.bar == 3"
+
+    // for loop
+    [ { for _ in 0..elem { elem; } elem } ==  3 ] => "Assertion failed: { for _ in 0..elem { elem; } elem } == 3"
+
+    // if
+    [ if true { elem } else { elem } == 3 ] => "Assertion failed: if true { elem } else { elem } == 3"
+
+    // inline asm
+
+    // let
+    [ if let true = true { elem } else { elem } == 3 ] => "Assertion failed: if let true = true { elem } else { elem } == 3"
+
+    // lit
+
+    // loop
+    [ loop { elem; break elem; } == 3 ] => "Assertion failed: loop { elem; break elem; } == 3"
+
+    // mac call
+
+    // match
+    [ match elem { _ => elem } == 3 ] => "Assertion failed: match elem { _ => elem, } == 3"
+
+    // ret
+    [ (|| { return elem; })() == 3 ] => "Assertion failed: (|| { return elem; })() == 3"
+
+    // try
+    [ (|| { Some(Some(elem)?) })() == Some(3) ] => "Assertion failed: (|| { Some(Some(elem)?) })() == Some(3)"
+
+    // try block
+
+    // underscore
+
+    // while
+    [ { while false { elem; break; } elem } == 3 ] => "Assertion failed: { while false { elem; break; } elem } == 3"
+
+    // yeet
+
+    // yield
+  );
+}