Add gen test for deriving hash for heterogenous tags

crates/compiler/test_gen/src/gen_abilities.rs

@@ -1332,7 +1332,7 @@ mod hash {
     }
 
     mod derived {
-        use super::{assert_evals_to, build_test};
+        use super::{assert_evals_to, build_test, indoc, TEST_HASHER};
         use roc_std::RocList;
 
         #[test]
@@ -1372,5 +1372,46 @@ mod hash {
                 RocList<u8>
             )
         }
+
+        #[test]
+        fn hash_heterogenous_tags() {
+            assert_evals_to!(
+                &format!(
+                    indoc!(
+                        r#"
+                        app "test" provides [main] to "./platform"
+
+                        {}
+
+                        a : [A U8 U8, B {{ a: U8 }}, C Str]
+                        a = A 15 23
+
+                        b : [A U8 U8, B {{ a: U8 }}, C Str]
+                        b = B {{ a: 37 }}
+
+                        c : [A U8 U8, B {{ a: U8 }}, C Str]
+                        c = C "abc"
+
+                        main =
+                            @THasher []
+                            |> Hash.hash a
+                            |> Hash.hash b
+                            |> Hash.hash c
+                            |> tRead
+                        "#
+                    ),
+                    TEST_HASHER,
+                ),
+                RocList::from_slice(&[
+                    0, 0, // dicsr A
+                    15, 23, // payloads A
+                    1, 0,  // discr B
+                    37, // payloads B
+                    2, 0, // discr B
+                    97, 98, 99 // payloads C
+                ]),
+                RocList<u8>
+            )
+        }
     }
 }