Test reporting lack of to in app header

crates/compiler/load/tests/test_reporting.rs

@@ -5982,6 +5982,33 @@ In roc, functions are always written as a lambda, like{}
         )
     }
 
+    #[test]
+    fn provides_missing_to_in_app_header() {
+        report_header_problem_as(
+            indoc!(
+                r#"
+                app "broken"
+                    provides [main]
+                "#
+            ),
+            indoc!(
+                r#"
+                ── WEIRD PROVIDES ──────────────────────────────────────── /code/proj/Main.roc ─
+
+                I am partway through parsing a header, but I got stuck here:
+
+                1│  app "broken"
+                2│      provides [main]
+                                       ^
+
+                I am expecting the `to` keyword next, like
+
+                    to pf
+                "#
+            ),
+        )
+    }
+
     #[test]
     fn platform_requires_rigids() {
         report_header_problem_as(