fix #3282 avoid in-place dict updates (#3405)

* fix #3282 avoid in-place dict updates

* add tests and changelog for PR3405

.gitignore

@@ -40,6 +40,7 @@ demo/*/config.json
 
 # Etc
 .idea/*
+.vscode/*
 .DS_Store
 *.bak
 workspace.code-workspace

gradio/blocks.py

@@ -251,6 +251,7 @@ class Block:
 
     @classmethod
     def get_specific_update(cls, generic_update: Dict[str, Any]) -> Dict:
+        generic_update = generic_update.copy()
         del generic_update["__type__"]
         specific_update = cls.update(**generic_update)
         return specific_update

test/test_blocks.py

@@ -484,6 +484,22 @@ class TestBlocksPostprocessing:
         output = demo.postprocess_data(0, gr.update(value="NO_VALUE"), state={})
         assert output[0]["value"] == "NO_VALUE"
 
+    def test_blocks_does_not_del_dict_keys_inplace(self):
+        with gr.Blocks() as demo:
+            im_list = [gr.Image() for i in range(2)]
+
+            def change_visibility(value):
+                return [gr.update(visible=value)] * 2
+
+            checkbox = gr.Checkbox(value=True, label="Show image")
+            checkbox.change(change_visibility, inputs=checkbox, outputs=im_list)
+
+        output = demo.postprocess_data(0, [gr.update(visible=False)] * 2, state={})
+        assert output == [
+            {"visible": False, "__type__": "update"},
+            {"visible": False, "__type__": "update"},
+        ]
+
     def test_blocks_returns_correct_output_dict_single_key(self):
         with gr.Blocks() as demo:
             num = gr.Number()