fix(docref): json serialization (#28182)

.pre-commit-config.yaml

@@ -5,19 +5,18 @@ fail_fast: false
 
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.3.0
+    rev: v5.0.0
     hooks:
       - id: trailing-whitespace
         files: "frappe.*"
         exclude: ".*json$|.*txt$|.*csv|.*md|.*svg"
-      - id: check-yaml
       - id: no-commit-to-branch
         args: ['--branch', 'develop']
       - id: check-merge-conflict
       - id: check-ast
       - id: check-json
       - id: check-toml
-      - id: check-yaml
+      # - id: check-yaml
       - id: debug-statements
         exclude: ^frappe/tests/classes/context_managers\.py$
 

frappe/utils/response.py

@@ -221,6 +221,10 @@ def json_handler(obj):
 
 	elif isinstance(obj, frappe.model.document.BaseDocument):
 		return obj.as_dict(no_nulls=True)
+
+	elif isinstance(obj, frappe.model.document.DocRef):  # if not BaseDocument, but DocRef
+		return str(obj)
+
 	elif isinstance(obj, Iterable):
 		return list(obj)