1 files changed, 47 insertions, 0 deletions
diff --git a/tests/ui/proc-macro/auxiliary/modify-ast.rs b/tests/ui/proc-macro/auxiliary/modify-ast.rs
new file mode 100644
index 00000000000..cc582c1522c
--- /dev/null
+++ b/tests/ui/proc-macro/auxiliary/modify-ast.rs
@@ -0,0 +1,47 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+
+use proc_macro::*;
+
+#[proc_macro_attribute]
+pub fn assert1(_a: TokenStream, b: TokenStream) -> TokenStream {
+    assert_eq(b.clone(), "pub fn foo() {}".parse().unwrap());
+    b
+}
+
+#[proc_macro_derive(Foo, attributes(foo))]
+pub fn assert2(a: TokenStream) -> TokenStream {
+    assert_eq(a, "pub struct MyStructc { _a: i32, }".parse().unwrap());
+    TokenStream::new()
+}
+
+fn assert_eq(a: TokenStream, b: TokenStream) {
+    let mut a = a.into_iter();
+    let mut b = b.into_iter();
+    for (a, b) in a.by_ref().zip(&mut b) {
+        match (a, b) {
+            (TokenTree::Group(a), TokenTree::Group(b)) => {
+                assert_eq!(a.delimiter(), b.delimiter());
+                assert_eq(a.stream(), b.stream());
+            }
+            (TokenTree::Punct(a), TokenTree::Punct(b)) => {
+                assert_eq!(a.as_char(), b.as_char());
+                assert_eq!(a.spacing(), b.spacing());
+            }
+            (TokenTree::Literal(a), TokenTree::Literal(b)) => {
+                assert_eq!(a.to_string(), b.to_string());
+            }
+            (TokenTree::Ident(a), TokenTree::Ident(b)) => {
+                assert_eq!(a.to_string(), b.to_string());
+            }
+            (a, b) => panic!("{:?} != {:?}", a, b),
+        }
+    }
+
+    assert!(a.next().is_none());
+    assert!(b.next().is_none());
+}