chore: add a failing test for #8780

compiler/noirc_frontend/src/tests/traits.rs

@@ -1,7 +1,7 @@
 use crate::elaborator::FrontendOptions;
 
-use crate::assert_no_errors;
 use crate::tests::Expect;
+use crate::{assert_no_errors, check_monomorphization_error};
 use crate::{check_errors, get_program_with_options};
 
 #[named]
@@ -1628,3 +1628,47 @@ fn accesses_associated_type_inside_trait_using_self() {
     "#;
     assert_no_errors!(src);
 }
+
+#[named]
+#[test]
+fn serialize_test_with_a_previous_unrelated_definition() {
+    let src = r#"
+    // If you remove this Trait definition, the code compiles fine. That's the bug.
+    pub trait Trait {}
+
+    trait Serialize {
+        let Size: u32;
+
+        fn serialize(self);
+    }
+
+    impl<A, B> Serialize for (A, B)
+    where
+        A: Serialize,
+        B: Serialize,
+    {
+        let Size: u32 = <A as Serialize>::Size + <B as Serialize>::Size;
+
+        fn serialize(self: Self) {
+            self.0.serialize();
+            ^^^^^^^^^^^^^^^^ No matching impl found for `(Field, Field): Serialize<Size = (3 - _)>`
+            ~~~~~~~~~~~~~~~~ No impl for `(Field, Field): Serialize<Size = (3 - _)>`
+        }
+    }
+
+    impl Serialize for Field {
+        let Size: u32 = 1;
+
+        fn serialize(self) { }
+    }
+
+    fn main() {
+        let x = (((1, 2), 5), 9);
+        x.serialize();
+    }
+    "#;
+
+    // In reality there should be no error here, so any error squiggles should be removed.
+    // See https://github.com/noir-lang/noir/issues/8780
+    check_monomorphization_error!(&src);
+}

test_programs/compile_failure/noirc_frontend_tests_traits_serialize_test_with_a_previous_unrelated_definition/Nargo.toml

@@ -0,0 +1,7 @@
+
+            [package]
+            name = "noirc_frontend_tests_traits_serialize_test_with_a_previous_unrelated_definition"
+            type = "bin"
+            authors = [""]
+
+            [dependencies]

test_programs/compile_failure/noirc_frontend_tests_traits_serialize_test_with_a_previous_unrelated_definition/src/main.nr

@@ -0,0 +1,33 @@
+
+    // If you remove this Trait definition, the code compiles fine. That's the bug.
+    pub trait Trait {}
+
+    trait Serialize {
+        let Size: u32;
+
+        fn serialize(self);
+    }
+
+    impl<A, B> Serialize for (A, B)
+    where
+        A: Serialize,
+        B: Serialize,
+    {
+        let Size: u32 = <A as Serialize>::Size + <B as Serialize>::Size;
+
+        fn serialize(self: Self) {
+            self.0.serialize();
+        }
+    }
+
+    impl Serialize for Field {
+        let Size: u32 = 1;
+
+        fn serialize(self) { }
+    }
+
+    fn main() {
+        let x = (((1, 2), 5), 9);
+        x.serialize();
+    }
+

test_programs/compile_failure/noirc_frontend_tests_traits_serialize_test_with_a_previous_unrelated_definition/src_hash.txt

@@ -0,0 +1 @@
+6336765763415174448

tooling/nargo_cli/build.rs

@@ -128,7 +128,7 @@
     // There's no "src/main.nr" here so it's trickier to make this work
     "overlapping_dep_and_mod",
     // bug
     "poseidonsponge_x5_254",
     // bug
     "regression_5045",
     // bug
@@ -192,7 +192,7 @@
 
 /// These tests are ignored because of existing bugs in `nargo expand`.
 /// As the bugs are fixed these tests should be removed from this list.
-const IGNORED_NARGO_EXPAND_COMPILE_SUCCESS_NO_BUG_TESTS: [&str; 16] = [
+const IGNORED_NARGO_EXPAND_COMPILE_SUCCESS_NO_BUG_TESTS: [&str; 17] = [
     "noirc_frontend_tests_arithmetic_generics_checked_casts_do_not_prevent_canonicalization",
     "noirc_frontend_tests_check_trait_as_type_as_fn_parameter",
     "noirc_frontend_tests_check_trait_as_type_as_two_fn_parameters",
@@ -201,6 +201,7 @@
     "noirc_frontend_tests_traits_calls_trait_function_if_it_is_in_scope",
     "noirc_frontend_tests_traits_calls_trait_function_if_it_is_only_candidate_in_scope",
     "noirc_frontend_tests_traits_calls_trait_function_if_it_is_only_candidate_in_scope_in_nested_module_using_super",
+    "noirc_frontend_tests_traits_serialize_test_with_a_previous_unrelated_definition",
     "noirc_frontend_tests_traits_trait_alias_polymorphic_inheritance",
     "noirc_frontend_tests_traits_trait_alias_single_member",
     "noirc_frontend_tests_traits_trait_alias_two_members",
@@ -689,7 +690,7 @@
     writeln!(test_file, "}}").unwrap();
 }
 
 /// Here we check, for every program in `test_programs/exeuction_success`, that:
 /// 1. `nargo expand` works on it
 /// 2. That the output of the original program is the same as the output of the expanded program
 ///    (that is, we run `nargo execute` on the original program and the expanded program and compare the output)