Handle RPC failure in AsyncSubtensor.all_subnets / get_all_subnets_info

bittensor/core/async_subtensor.py

@@ -1046,6 +1046,14 @@ async def all_subnets(
             return_exceptions=True,
         )
 
+        if isinstance(decoded, Exception):
+            # ``return_exceptions=True`` surfaces a failed runtime call as the
+            # ``decoded`` value; iterating it below would raise TypeError.
+            logging.warning(
+                f"Unable to fetch all subnets info for block {block}, block hash {block_hash}: {decoded}"
+            )
+            return None
+
         if not isinstance(subnet_prices, (SubstrateRequestException, ValueError)):
             for sn in decoded:
                 sn.update(
@@ -1409,6 +1417,13 @@ async def get_all_subnets_info(
             ),
             return_exceptions=True,
         )
+        if isinstance(result, Exception):
+            # ``return_exceptions=True`` surfaces a failed runtime call as the
+            # ``result`` value; SubnetInfo.list_from_dicts would then raise TypeError.
+            logging.warning(
+                f"Unable to fetch all subnets info for block {block}, block hash {block_hash}: {result}"
+            )
+            return []
         if not result:
             return []
 

mypy.ini

@@ -1,6 +1,13 @@
 [mypy]
 ignore_missing_imports = True
 ignore_errors = True
+follow_imports_for_stubs = True
+
+[mypy-numpy.*]
+follow_imports = skip
+
+[mypy-numpy]
+follow_imports = skip
 
 [mypy-*.axon.*]
 ignore_errors = False

tests/unit_tests/test_async_subtensor.py

@@ -2819,6 +2819,27 @@ async def test_get_all_subnets_info_success(mocker, subtensor):
     )
 
 
+@pytest.mark.asyncio
+async def test_get_all_subnets_info_returns_empty_on_rpc_error(mocker, subtensor):
+    """If the runtime call fails, gather(return_exceptions=True) yields the exception as
+    ``result``; get_all_subnets_info must return [] instead of crashing inside
+    SubnetInfo.list_from_dicts with a TypeError."""
+    mocker.patch.object(subtensor, "get_subnet_prices", return_value={})
+    mocker.patch.object(
+        subtensor,
+        "query_runtime_api",
+        side_effect=async_subtensor.SubstrateRequestException("rpc down"),
+    )
+    mocked_list_from_dicts = mocker.patch.object(
+        async_subtensor.SubnetInfo, "list_from_dicts"
+    )
+
+    result = await subtensor.get_all_subnets_info()
+
+    assert result == []
+    mocked_list_from_dicts.assert_not_called()
+
+
 @pytest.mark.asyncio
 async def test_set_subnet_identity(mocker, subtensor, fake_wallet):
     """Verify that subtensor method `set_subnet_identity` calls proper function with proper arguments."""
@@ -3768,6 +3789,24 @@ async def test_all_subnets(subtensor, mocker):
     assert result == mocked_di_list_from_dicts.return_value
 
 
+@pytest.mark.asyncio
+async def test_all_subnets_returns_none_on_rpc_error(subtensor, mocker):
+    """If the runtime call fails, gather(return_exceptions=True) yields the exception as
+    ``decoded``; all_subnets must return None (its documented failure value) instead of
+    raising TypeError while trying to iterate the exception."""
+    mocker.patch.object(subtensor, "determine_block_hash")
+    mocker.patch.object(subtensor, "get_subnet_prices", return_value={})
+    mocker.patch.object(
+        subtensor.substrate,
+        "runtime_call",
+        side_effect=async_subtensor.SubstrateRequestException("rpc down"),
+    )
+
+    result = await subtensor.all_subnets()
+
+    assert result is None
+
+
 @pytest.mark.asyncio
 async def test_subnet(subtensor, mocker):
     """Verify that `subnet` calls proper methods and returns the correct value."""