fix(wren): report a validation error for non-scalar model/view names

core/wren/src/wren/context.py

@@ -965,6 +965,15 @@ def validate_project(project_path: Path) -> list[ValidationError]:
         src = model.get("_source_dir", f"models[{i}]")
         src_path = f"models/{src}/metadata.yml"
         name = model.get("name")
+        if isinstance(name, (list, dict)):
+            errors.append(
+                ValidationError(
+                    "error",
+                    src_path,
+                    f"model 'name' must be a scalar value, got {type(name).__name__}",
+                )
+            )
+            continue
         if not name:
             errors.append(ValidationError("error", src_path, "model missing 'name'"))
             continue
@@ -1213,6 +1222,15 @@ def validate_project(project_path: Path) -> list[ValidationError]:
     for i, view in enumerate(views):
         src_dir = view.get("_source_dir", f"views[{i}]")
         name = view.get("name")
+        if isinstance(name, (list, dict)):
+            errors.append(
+                ValidationError(
+                    "error",
+                    f"views/{src_dir}/metadata.yml",
+                    f"view 'name' must be a scalar value, got {type(name).__name__}",
+                )
+            )
+            continue
         if not name:
             errors.append(
                 ValidationError(

core/wren/tests/unit/test_context.py

@@ -555,6 +555,75 @@ def test_validate_duplicate_model(tmp_path):
     assert any("duplicate model name" in e.message for e in errors)
 
 
+def test_validate_model_name_list_reports_error(tmp_path):
+    _make_v2_project(tmp_path)
+    d = tmp_path / "models" / "orders"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text(
+        "name: [a, b]\ntable_reference:\n  table: orders\ncolumns: []\n"
+    )
+    errors = validate_project(tmp_path)
+    assert any(
+        "model 'name' must be a scalar value, got list" in e.message for e in errors
+    )
+
+
+def test_validate_model_name_dict_reports_error(tmp_path):
+    _make_v2_project(tmp_path)
+    d = tmp_path / "models" / "orders"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text(
+        "name: {x: 1}\ntable_reference:\n  table: orders\ncolumns: []\n"
+    )
+    errors = validate_project(tmp_path)
+    assert any(
+        "model 'name' must be a scalar value, got dict" in e.message for e in errors
+    )
+
+
+def test_validate_model_name_int_is_not_rejected(tmp_path):
+    # An int name is unusual but hashable, so it never hit the crash this guard
+    # exists for; the guard must not turn it into a new validation error.
+    _make_v2_project(tmp_path)
+    d = tmp_path / "models" / "orders"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text(
+        "name: 3\ntable_reference:\n  table: orders\ncolumns: []\n"
+    )
+    errors = validate_project(tmp_path)
+    assert not any("must be a scalar value" in e.message for e in errors)
+
+
+def test_validate_model_name_empty_list_reports_scalar_error_not_missing(tmp_path):
+    # An empty list is falsy, so the type guard must run before the missing-name
+    # check or this reports "missing 'name'" instead of the malformed type.
+    _make_v2_project(tmp_path)
+    d = tmp_path / "models" / "orders"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text(
+        "name: []\ntable_reference:\n  table: orders\ncolumns: []\n"
+    )
+    errors = validate_project(tmp_path)
+    assert any(
+        "model 'name' must be a scalar value, got list" in e.message for e in errors
+    )
+    assert not any("model missing 'name'" in e.message for e in errors)
+
+
+def test_validate_model_name_empty_dict_reports_scalar_error_not_missing(tmp_path):
+    _make_v2_project(tmp_path)
+    d = tmp_path / "models" / "orders"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text(
+        "name: {}\ntable_reference:\n  table: orders\ncolumns: []\n"
+    )
+    errors = validate_project(tmp_path)
+    assert any(
+        "model 'name' must be a scalar value, got dict" in e.message for e in errors
+    )
+    assert not any("model missing 'name'" in e.message for e in errors)
+
+
 def test_validate_both_tref_and_ref_sql(tmp_path):
     _make_v2_project(tmp_path)
     d = tmp_path / "models" / "conflict"
@@ -682,6 +751,54 @@ def test_validate_view_no_statement(tmp_path):
     assert any("missing 'statement'" in e.message for e in errors)
 
 
+def test_validate_view_name_list_reports_error(tmp_path):
+    _make_v2_project(tmp_path)
+    d = tmp_path / "views" / "monthly"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text("name: [a, b]\nstatement: SELECT 1\n")
+    errors = validate_project(tmp_path)
+    assert any(
+        "view 'name' must be a scalar value, got list" in e.message for e in errors
+    )
+
+
+def test_validate_view_name_dict_reports_error(tmp_path):
+    _make_v2_project(tmp_path)
+    d = tmp_path / "views" / "monthly"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text("name: {x: 1}\nstatement: SELECT 1\n")
+    errors = validate_project(tmp_path)
+    assert any(
+        "view 'name' must be a scalar value, got dict" in e.message for e in errors
+    )
+
+
+def test_validate_view_name_empty_list_reports_scalar_error_not_missing(tmp_path):
+    # An empty list is falsy, so the type guard must run before the missing-name
+    # check or this reports "missing 'name'" instead of the malformed type.
+    _make_v2_project(tmp_path)
+    d = tmp_path / "views" / "monthly"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text("name: []\nstatement: SELECT 1\n")
+    errors = validate_project(tmp_path)
+    assert any(
+        "view 'name' must be a scalar value, got list" in e.message for e in errors
+    )
+    assert not any("view missing 'name'" in e.message for e in errors)
+
+
+def test_validate_view_name_empty_dict_reports_scalar_error_not_missing(tmp_path):
+    _make_v2_project(tmp_path)
+    d = tmp_path / "views" / "monthly"
+    d.mkdir(parents=True)
+    (d / "metadata.yml").write_text("name: {}\nstatement: SELECT 1\n")
+    errors = validate_project(tmp_path)
+    assert any(
+        "view 'name' must be a scalar value, got dict" in e.message for e in errors
+    )
+    assert not any("view missing 'name'" in e.message for e in errors)
+
+
 def test_validate_missing_join_type(tmp_path):
     _make_valid_project(tmp_path)
     (tmp_path / "relationships.yml").write_text(