From ef28a5afbc5f706f57da6e0309116ab996ee3d47 Mon Sep 17 00:00:00 2001
From: Marton Vago <marci.vago@gmail.com>
Date: Fri, 7 Nov 2025 10:51:07 +0000
Subject: [PATCH] feat: :sparkles: handle grouped errors for primary key

---
 src/check_datapackage/check.py | 35 +++++++++++++++++++++++++++
 tests/test_check.py            | 43 ++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+)

diff --git a/src/check_datapackage/check.py b/src/check_datapackage/check.py
index c0fd1994..30953939 100644
--- a/src/check_datapackage/check.py
+++ b/src/check_datapackage/check.py
@@ -304,12 +304,47 @@ def _handle_S_resources_x_schema_fields_x(
     return edits
 
 
+def _handle_S_resources_x_schema_primary_key(
+    parent_error: SchemaError,
+    schema_errors: list[SchemaError],
+) -> SchemaErrorEdits:
+    """Only flag errors for the relevant type and simplify errors."""
+    PRIMARY_KEY_TYPES: tuple[type[Any], ...] = (list, str)
+    edits = SchemaErrorEdits(remove=[parent_error])
+    errors_in_group = _get_errors_in_group(schema_errors, parent_error)
+
+    key_type = type(parent_error.instance)
+    if key_type in PRIMARY_KEY_TYPES:
+        schema_for_type = f"primaryKey/oneOf/{PRIMARY_KEY_TYPES.index(key_type)}/"
+        edits.remove.extend(
+            _filter(
+                errors_in_group,
+                lambda error: schema_for_type not in error.schema_path,
+            )
+        )
+        return edits
+
+    edits.remove.extend(errors_in_group)
+    edits.add.append(
+        SchemaError(
+            message="The `primaryKey` property must be a string or an array.",
+            type="type",
+            jsonpath=parent_error.jsonpath,
+            schema_path=parent_error.schema_path,
+            instance=parent_error.instance,
+        )
+    )
+
+    return edits
+
+
 _schema_path_to_handler: list[
     tuple[str, Callable[[SchemaError, list[SchemaError]], SchemaErrorEdits]]
 ] = [
     ("resources/items/oneOf", _handle_S_resources_x),
     ("resources/items/properties/path/oneOf", _handle_S_resources_x_path),
     ("fields/items/oneOf", _handle_S_resources_x_schema_fields_x),
+    ("primaryKey/oneOf", _handle_S_resources_x_schema_primary_key),
 ]
 
 
diff --git a/tests/test_check.py b/tests/test_check.py
index 82156784..33a984d5 100644
--- a/tests/test_check.py
+++ b/tests/test_check.py
@@ -333,6 +333,49 @@ def test_fail_unknown_field_with_bad_property():
     assert issues[0].jsonpath == "$.resources[0].schema.fields[0].type"
 
 
+@mark.parametrize("primary_key", ["id", ["name", "address"]])
+def test_pass_good_primary_key(primary_key):
+    properties = example_package_properties()
+    properties["resources"][0]["schema"]["primaryKey"] = primary_key
+
+    issues = check(properties)
+
+    assert issues == []
+
+
+def test_fail_primary_key_of_bad_type():
+    properties = example_package_properties()
+    properties["resources"][0]["schema"]["primaryKey"] = 123
+
+    issues = check(properties)
+
+    assert len(issues) == 1
+    assert issues[0].type == "type"
+    assert issues[0].jsonpath == "$.resources[0].schema.primaryKey"
+
+
+def test_fail_primary_key_with_bad_array():
+    properties = example_package_properties()
+    properties["resources"][0]["schema"]["primaryKey"] = []
+
+    issues = check(properties)
+
+    assert len(issues) == 1
+    assert issues[0].type == "minItems"
+    assert issues[0].jsonpath == "$.resources[0].schema.primaryKey"
+
+
+def test_fail_primary_key_with_bad_array_item():
+    properties = example_package_properties()
+    properties["resources"][0]["schema"]["primaryKey"] = [123, "name"]
+
+    issues = check(properties)
+
+    assert len(issues) == 1
+    assert issues[0].type == "type"
+    assert issues[0].jsonpath == "$.resources[0].schema.primaryKey[0]"
+
+
 def test_error_as_true():
     properties = {
         "name": 123,