From f9e70654a2a4bf30ee68d7404da31918c8548d4d Mon Sep 17 00:00:00 2001
From: Mrinal Chanshetty <mrinal@berri.ai>
Date: Tue, 20 Oct 2026 16:08:21 -0700
Subject: [PATCH] fix(ci): stop the schema compatibility check reading block
 attributes as fields

parse_model_fields split every model line on whitespace and keyed it by the
first token, so @@unique([tag, date, ...]) became a field named "@@unique([tag,"
and its column list its type. Changing a composite unique key failed the check
as a type change, and @@ lines sharing that first token overwrote each other,
so most of them were never compared. Comment lines were read as fields too.

Block attributes and comments are now skipped, so the check compares columns,
which is what its messages and tests describe.
---
 scripts/check_schema_compatibility.py      |  6 +++++-
 tests/unit/proxy/test_db_schema_changes.py | 22 ++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/scripts/check_schema_compatibility.py b/scripts/check_schema_compatibility.py
index 898c65dff2c..5e98db3c7e2 100644
--- a/scripts/check_schema_compatibility.py
+++ b/scripts/check_schema_compatibility.py
@@ -15,10 +15,14 @@ Schema = Mapping[str, Mapping[str, str]]
 MODELS: Final = re.compile(r"^[ \t]*model\s+(\w+)\s*\{(.*?)^[ \t]*\}", re.MULTILINE | re.DOTALL)
 
 
+def _is_field(part: list[str]) -> bool:
+    return len(part) >= 2 and not part[0].startswith(("@@", "//"))
+
+
 def parse_model_fields(schema: str) -> Schema:
     def fields(body: str) -> Mapping[str, str]:
         parts: Final = tuple(line.split() for line in body.splitlines())
-        return MappingProxyType({part[0]: " ".join(part[1:]) for part in parts if len(part) >= 2})
+        return MappingProxyType({part[0]: " ".join(part[1:]) for part in parts if _is_field(part)})
 
     return MappingProxyType({match[1]: fields(match[2]) for match in MODELS.finditer(schema)})
 
diff --git a/tests/unit/proxy/test_db_schema_changes.py b/tests/unit/proxy/test_db_schema_changes.py
index 3a5d0fb1a0a..49dfaec1f16 100644
--- a/tests/unit/proxy/test_db_schema_changes.py
+++ b/tests/unit/proxy/test_db_schema_changes.py
@@ -16,6 +16,28 @@ def test_parse_model_fields_retains_types_and_attributes() -> None:
     assert parse_model_fields(ORIGINAL) == {"Item": {"id": "String @id", "label": "String?"}}
 
 
+def test_block_attributes_and_comments_are_not_fields() -> None:
+    schema: Final = (
+        "model Item {\n id String @id\n label String?\n // free text\n"
+        ' @@unique([label, id], map: "item_label_id_key")\n @@index([label, id])\n @@index([id])\n}\n'
+    )
+    assert parse_model_fields(schema) == {"Item": {"id": "String @id", "label": "String?"}}
+
+
+def test_changing_a_composite_unique_key_is_not_a_field_change() -> None:
+    before: Final = "model Item {\n id String @id\n label String?\n @@unique([label, id])\n}\n"
+    after: Final = "model Item {\n id String @id\n label String?\n @@unique([label, id, tenant])\n}\n"
+    assert check_breaking_changes(parse_model_fields(before), parse_model_fields(after)) == ()
+
+
+def test_a_narrowed_column_is_still_caught_next_to_block_attributes() -> None:
+    before: Final = "model Item {\n id String @id\n label String?\n @@index([label, id])\n}\n"
+    after: Final = "model Item {\n id String @id\n label String\n @@index([label, id])\n}\n"
+    assert check_breaking_changes(parse_model_fields(before), parse_model_fields(after)) == (
+        "Breaking: Field Item.label changed from optional to required",
+    )
+
+
 def test_parse_model_fields_keeps_json_defaults_and_empty_models() -> None:
     schema: Final = 'model Item {\n data Json @default("{}")\n}\nmodel Empty {\n}\n'
     assert parse_model_fields(schema) == {"Item": {"data": 'Json @default("{}")'}, "Empty": {}}