Fix JSON schema provider crash for Dict/List fields (#2037)

news/2037.bugfix

@@ -0,0 +1 @@
+Fix crash in JSON schema providers for Dict and List fields when sub-types are missing by making adapter lookups safe.

src/plone/restapi/tests/test_types.py

@@ -797,3 +797,37 @@ def test_jsonfield(self):
             },
             adapter.get_schema(),
         )
+
+    def test_dict_without_types(self):
+        field = schema.Dict(title="My field", description="My great field")
+        adapter = getMultiAdapter(
+            (field, self.portal, self.request), IJsonSchemaProvider
+        )
+        # This currently crashes with ComponentLookupError
+        self.assertEqual(
+            {
+                "type": "dict",
+                "title": "My field",
+                "description": "My great field",
+            },
+            adapter.get_schema(),
+        )
+
+    def test_list_without_value_type(self):
+        field = schema.List(title="My field", description="My great field")
+        adapter = getMultiAdapter(
+            (field, self.portal, self.request), IJsonSchemaProvider
+        )
+        # This currently crashes with ComponentLookupError
+        self.assertEqual(
+            {
+                "type": "array",
+                "title": "My field",
+                "description": "My great field",
+                "factory": "List",
+                "uniqueItems": False,
+                "additionalItems": True,
+                "items": {},
+            },
+            adapter.get_schema(),
+        )

src/plone/restapi/types/adapters.py

@@ -13,7 +13,7 @@
 from plone.schema import IJSONField
 from z3c.formwidget.query.interfaces import IQuerySource
 from zope.component import adapter
-from zope.component import getMultiAdapter
+from zope.component import queryMultiAdapter
 from zope.i18n import translate
 from zope.interface import implementer
 from zope.interface import Interface
@@ -270,11 +270,16 @@ def get_factory(self):
 
     def get_items(self):
         """Get items properties."""
-        value_type_adapter = getMultiAdapter(
-            (self.field.value_type, self.context, self.request), IJsonSchemaProvider
-        )
-
-        return value_type_adapter.get_schema()
+        if self.field.value_type:
+            value_type_adapter = queryMultiAdapter(
+                (self.field.value_type, self.context, self.request), IJsonSchemaProvider
+            )
+            if value_type_adapter:
+                try:
+                    return value_type_adapter.get_schema()
+                except NotImplementedError:
+                    pass
+        return {}
 
     def additional(self):
         info = {}
@@ -434,20 +439,30 @@ def get_type(self):
 
     def additional(self):
         info = {}
-        key_type = getMultiAdapter(
-            (self.field.key_type, self.context, self.request), IJsonSchemaProvider
-        )
-        info["key_type"] = {
-            "schema": key_type.get_schema(),
-            "additional": key_type.additional(),
-        }
-        value_type = getMultiAdapter(
-            (self.field.value_type, self.context, self.request), IJsonSchemaProvider
-        )
-        info["value_type"] = {
-            "schema": value_type.get_schema(),
-            "additional": value_type.additional(),
-        }
+        if self.field.key_type:
+            key_type = queryMultiAdapter(
+                (self.field.key_type, self.context, self.request), IJsonSchemaProvider
+            )
+            if key_type:
+                try:
+                    info["key_type"] = {
+                        "schema": key_type.get_schema(),
+                        "additional": key_type.additional(),
+                    }
+                except NotImplementedError:
+                    pass
+        if self.field.value_type:
+            value_type = queryMultiAdapter(
+                (self.field.value_type, self.context, self.request), IJsonSchemaProvider
+            )
+            if value_type:
+                try:
+                    info["value_type"] = {
+                        "schema": value_type.get_schema(),
+                        "additional": value_type.additional(),
+                    }
+                except NotImplementedError:
+                    pass
         return info