fix: support app client instantiation from arc4

src/algokit_utils/applications/app_spec/arc56.py

@@ -455,7 +455,10 @@ def to_abi_method(self) -> AlgosdkMethod:
 
     @staticmethod
     def from_dict(data: dict[str, Any]) -> Method:
-        data["actions"] = Actions.from_dict(data["actions"])
+        if data.get("actions"):
+            data["actions"] = Actions.from_dict(data["actions"])
+        else:
+            data["actions"] = Actions(call=list(CallEnum), create=list(CreateEnum))
         data["args"] = [MethodArg.from_dict(item) for item in data["args"]]
         data["returns"] = Returns.from_dict(data["returns"])
         if data.get("events"):
@@ -888,19 +891,38 @@ class Arc56Contract:
     """The optional template variable information"""
 
     @staticmethod
-    def from_dict(application_spec: dict) -> Arc56Contract:
+    def from_dict(application_spec: dict) -> Arc56Contract:  # noqa: C901, PLR0912
         """Create Arc56Contract from dictionary.
 
         :param application_spec: Dictionary containing contract specification
         :return: Arc56Contract instance
         """
         data = _dict_keys_to_snake_case(application_spec)
-        data["bare_actions"] = BareActions.from_dict(data["bare_actions"])
+
+        if data.get("bare_actions"):
+            data["bare_actions"] = BareActions.from_dict(data["bare_actions"])
+        else:
+            data["bare_actions"] = BareActions(call=list(CallEnum), create=list(CreateEnum))
+
         data["methods"] = [Method.from_dict(item) for item in data["methods"]]
-        data["state"] = State.from_dict(data["state"])
-        data["structs"] = {
-            key: [StructField.from_dict(item) for item in value] for key, value in application_spec["structs"].items()
-        }
+
+        if data.get("state"):
+            data["state"] = State.from_dict(data["state"])
+        else:
+            data["state"] = State(
+                keys=Keys(box={}, global_state={}, local_state={}),
+                maps=Maps(box={}, global_state={}, local_state={}),
+                schema=Schema(global_state=Global(bytes=0, ints=0), local_state=Local(bytes=0, ints=0)),
+            )
+
+        if data.get("structs"):
+            data["structs"] = {
+                key: [StructField.from_dict(item) for item in value]
+                for key, value in application_spec["structs"].items()
+            }
+        else:
+            data["structs"] = {}
+
         if data.get("byte_code"):
             data["byte_code"] = ByteCode.from_dict(data["byte_code"])
         if data.get("compiler_info"):
@@ -921,6 +943,9 @@ def from_dict(application_spec: dict) -> Arc56Contract:
             data["template_variables"] = {
                 key: TemplateVariables.from_dict(value) for key, value in data["template_variables"].items()
             }
+
+        data["arcs"] = data.get("arcs", [4])
+
         return Arc56Contract(**data)
 
     @staticmethod

tests/applications/test_app_client.py

@@ -765,6 +765,11 @@ def nested_struct_app_spec() -> Arc56Contract:
     return Arc56Contract.from_json(raw_json_spec.read_text())
 
 
+def test_nested_struct_from_arc4() -> None:
+    raw_json_spec = Path(__file__).parent.parent / "artifacts" / "nested_struct" / "nested_struct.arc4.json"
+    Arc56Contract.from_json(raw_json_spec.read_text())
+
+
 def test_nested_structs_described_by_structure(
     algorand: AlgorandClient, funded_account: SigningAccount, nested_struct_app_spec: Arc56Contract
 ) -> None:

tests/artifacts/nested_struct/nested_struct.arc4.json

@@ -0,0 +1,41 @@
+{
+  "name": "NestedStruct",
+  "desc": "",
+  "methods": [
+    {
+      "name": "createApplication",
+      "args": [],
+      "returns": {
+        "type": "void"
+      }
+    },
+    {
+      "name": "setValue",
+      "args": [
+        {
+          "name": "key",
+          "type": "uint64"
+        },
+        {
+          "name": "value",
+          "type": "string"
+        }
+      ],
+      "returns": {
+        "type": "void"
+      }
+    },
+    {
+      "name": "getValue",
+      "args": [
+        {
+          "name": "key",
+          "type": "uint64"
+        }
+      ],
+      "returns": {
+        "type": "((string))"
+      }
+    }
+  ]
+}