mbe: Add error test for macro fragment fields

Author: joshtriplett

tests/ui/macros/macro-fragment-fields-errors.rs

@@ -0,0 +1,55 @@
+//@ edition:2024
+#![crate_type = "lib"]
+#![feature(macro_metavar_expr)]
+#![allow(incomplete_features)]
+#![feature(macro_fragment_fields)]
+#![feature(macro_fragments_more)]
+
+macro_rules! bad1 {
+    ($f:fn) => { ${f.unknown_field} };
+    //~^ ERROR: expression of type `fn` has no field `unknown_field`
+}
+
+bad1! { fn f() {} }
+
+macro_rules! bad2 {
+    ($f:fn) => { ${f.name.unknown_field} };
+    //~^ ERROR: expression of type `ident` has no field `unknown_field`
+}
+
+bad2! { fn f() {} }
+
+macro_rules! bad3 {
+    ($f:fn) => { ${f.name.unknown_field.unknown_field} };
+    //~^ ERROR: expression of type `ident` has no field `unknown_field`
+}
+
+bad3! { fn f() {} }
+
+macro_rules! bad4 {
+    ($f:item) => { ${f.name} };
+    //~^ ERROR: expression of type `item` has no field `name`
+}
+
+bad4! { fn f() {} }
+
+macro_rules! bad5 {
+    ($f:block) => { ${f.unknown_field} };
+    //~^ ERROR: expression of type `block` has no field `unknown_field`
+}
+
+bad5! { { 42; } }
+
+macro_rules! bad6 {
+    ($a:adt) => { ${a.unknown_field} };
+    //~^ ERROR: expression of type `adt` has no field `unknown_field`
+}
+
+bad6! { struct S; }
+
+macro_rules! bad7 {
+    ($a:adt) => { ${a.name.unknown_field} };
+    //~^ ERROR: expression of type `ident` has no field `unknown_field`
+}
+
+bad7! { struct S; }

tests/ui/macros/macro-fragment-fields-errors.stderr

@@ -0,0 +1,44 @@
+error: expression of type `fn` has no field `unknown_field`
+  --> $DIR/macro-fragment-fields-errors.rs:9:22
+   |
+LL |     ($f:fn) => { ${f.unknown_field} };
+   |                      ^^^^^^^^^^^^^
+
+error: expression of type `ident` has no field `unknown_field`
+  --> $DIR/macro-fragment-fields-errors.rs:16:27
+   |
+LL |     ($f:fn) => { ${f.name.unknown_field} };
+   |                           ^^^^^^^^^^^^^
+
+error: expression of type `ident` has no field `unknown_field`
+  --> $DIR/macro-fragment-fields-errors.rs:23:27
+   |
+LL |     ($f:fn) => { ${f.name.unknown_field.unknown_field} };
+   |                           ^^^^^^^^^^^^^
+
+error: expression of type `item` has no field `name`
+  --> $DIR/macro-fragment-fields-errors.rs:30:24
+   |
+LL |     ($f:item) => { ${f.name} };
+   |                        ^^^^
+
+error: expression of type `block` has no field `unknown_field`
+  --> $DIR/macro-fragment-fields-errors.rs:37:25
+   |
+LL |     ($f:block) => { ${f.unknown_field} };
+   |                         ^^^^^^^^^^^^^
+
+error: expression of type `adt` has no field `unknown_field`
+  --> $DIR/macro-fragment-fields-errors.rs:44:23
+   |
+LL |     ($a:adt) => { ${a.unknown_field} };
+   |                       ^^^^^^^^^^^^^
+
+error: expression of type `ident` has no field `unknown_field`
+  --> $DIR/macro-fragment-fields-errors.rs:51:28
+   |
+LL |     ($a:adt) => { ${a.name.unknown_field} };
+   |                            ^^^^^^^^^^^^^
+
+error: aborting due to 7 previous errors
+