feat(msc-steps): add SetConfigStep for runtime config mutation

CLAUDE.md

@@ -46,19 +46,19 @@ YAML Scene -> Steps -> Transactions/Queries -> MultiversX Network
 ### Key Directories
 | Directory | Purpose |
 |-----------|---------|
-| `mxops/execution/steps/` | All step implementations (28 types) |
+| `mxops/execution/steps/` | All step implementations (32 types) |
 | `mxops/smart_values/` | Dynamic value resolution (`%`, `$`, `&`, `=` syntax) |
 | `mxops/data/` | ScenarioData persistence per network+scenario |
 | `mxops/cli/` | CLI commands (execute, data, config, chain-simulator) |
 | `tests/` | Unit tests (pytest) |
 | `integration_tests/` | Chain-simulator/devnet integration tests |
 
-### All Step Types (29)
+### All Step Types (32)
 **Contracts**: `ContractDeploy`, `ContractUpgrade`, `ContractCall`, `ContractQuery`, `FileFuzzer`
 **Transfers**: `Transfer`
 **Tokens**: `FungibleIssue`, `NonFungibleIssue`, `SemiFungibleIssue`, `MetaIssue`, `FungibleMint`, `NonFungibleMint`, `ManageFungibleTokenRoles`, `ManageNonFungibleTokenRoles`, `ManageSemiFungibleTokenRoles`, `ManageMetaTokenRoles`
-**Setup**: `GenerateWallets`, `ChainSimulatorFaucet`, `R3D4Faucet`, `AccountClone`, `AccountBatchClone`
-**Control**: `Loop`, `Scene`, `SetVars`, `SetSeed`, `Assert`, `Wait`, `Log`, `Python`
+**Setup**: `GenerateWallets`, `ChainSimulatorFaucet`, `R3D4Faucet`, `AccountClone`, `AccountBatchClone`, `ChainSimulatorSetState`, `ChainSimulatorSetTokenBalance`
+**Control**: `Loop`, `Scene`, `SetVars`, `SetSeed`, `SetConfig`, `Assert`, `Wait`, `Log`, `Python`
 
 ### Smart Values Syntax
 | Symbol | Source | Example |

docs/dictionary/custom_wordlist.txt

@@ -5,6 +5,7 @@ AppFolder
 arg
 backend
 backoff
+behaviour
 bitwise
 blake
 blockchain

docs/source/dev_documentation/changelog.md

@@ -14,6 +14,7 @@
 - `_set_state_with_retry` helper for transient failure resilience on `set_state` calls
 - `PROXY_TIMEOUT` configuration parameter (default 10s, mainnet 30s, chain simulator 60s) to prevent read timeouts when fetching large contract storage
 - `AUTO_GENERATE_BLOCKS` chain simulator configuration parameter (default `true`) to control whether MxOps drives block production itself; set it to `false` when the simulator auto-generates blocks so MxOps behaves like on other networks
+- `SetConfigStep` to change a configuration option at runtime for the current network (process-only, never persisted), for example to toggle `AUTO_GENERATE_BLOCKS` mid-scene
 
 ### Changed
 

docs/source/user_documentation/chain_simulator.md

@@ -59,3 +59,8 @@ AUTO_GENERATE_BLOCKS=true
 
 This option only applies to the chain-simulator network and has no effect on
 other networks.
+
+You can also toggle this option mid-scene with the
+[Set Config step](set_config_step_target), for example to run fast
+MxOps-driven setup steps and then switch to `AUTO_GENERATE_BLOCKS=false` so the
+rest of the scene relies on the simulator's own block production.

docs/source/user_documentation/steps.md

@@ -928,6 +928,32 @@ variables:
 ```
 
 
+(set_config_step_target)=
+### Set Config Step
+
+This step allows you to change a [configuration](config) option at runtime for the network the scene is running against. This is useful when you want to alter MxOps behaviour mid-scene, for example to toggle `AUTO_GENERATE_BLOCKS` on the chain-simulator (see the [chain-simulator chapter](chain_simulator)):
+
+```yaml
+- type: SetConfig
+  option: AUTO_GENERATE_BLOCKS
+  value: "false"
+# ... steps that rely on the simulator auto-producing blocks ...
+- type: SetConfig
+  option: AUTO_GENERATE_BLOCKS
+  value: "true"
+```
+
+```{note}
+- The option is set on the **current network's** config section only. An unknown option name (e.g. a typo) raises an error rather than silently creating an unused key.
+- The change lasts for the current process only: it is never written to disk and each `mxops execute` run reloads the configuration from file.
+- Configuration values are strings. A non-string YAML scalar such as `value: false` is coerced to the string `"False"`, so quoting the value (`value: "false"`) is recommended for clarity.
+```
+
+```{warning}
+Only options that are read fresh on each use (such as `AUTO_GENERATE_BLOCKS`) take effect mid-scene. Connection-level options such as `PROXY` and `PROXY_TIMEOUT` are read once when the network provider is first created, so changing them with this step has no effect on the already-running process.
+```
+
+
 (wait_target)=
 ### Wait Step
 

mxops/errors.py

@@ -527,6 +527,16 @@ class InvalidConfigValue(Exception):
     """
 
 
+class UnknownConfigOption(Exception):
+    """
+    to be raised when a specified configuration option does not exist
+    """
+
+    def __init__(self, option: str, network_name: str) -> None:
+        message = f"Unknown config option '{option}' for network '{network_name}'"
+        super().__init__(message)
+
+
 class WrongFuzzTestFile(Exception):
     """
     to be raised when the file given for fuzz testing in not correctly formatted

mxops/execution/steps/__init__.py

@@ -10,6 +10,7 @@
     LoopStep,
     PythonStep,
     SceneStep,
+    SetConfigStep,
     SetSeedStep,
     SetVarsStep,
     WaitStep,
@@ -72,6 +73,7 @@
     "R3D4FaucetStep",
     "SceneStep",
     "SemiFungibleIssueStep",
+    "SetConfigStep",
     "SetSeedStep",
     "SetVarsStep",
     "TransferStep",

mxops/execution/steps/msc.py

@@ -14,6 +14,7 @@
 
 from mxops import errors
 from mxops.common.providers import MyProxyNetworkProvider, should_generate_blocks
+from mxops.config.config import Config
 from mxops.data.execution_data import ScenarioData
 from mxops.data.utils import json_dumps
 from mxops.enums import LogGroupEnum
@@ -137,6 +138,30 @@ def _execute(self):
             scenario_data.set_value(key, value)
 
 
+@dataclass
+class SetConfigStep(Step):
+    """
+    Represents a step to set a configuration option at runtime for the
+    current network.
+    """
+
+    option: SmartStr
+    value: SmartStr
+
+    def _execute(self):
+        """
+        Set the configuration option to the given value for the current network
+        """
+        logger = ScenarioData.get_scenario_logger(LogGroupEnum.EXEC)
+        option = self.option.get_evaluated_value()
+        value = self.value.get_evaluated_value()
+        config = Config.get_config()
+        if option.upper() not in config.get_options():
+            raise errors.UnknownConfigOption(option, config.get_network().name)
+        logger.info(f"Setting config option `{option}` to `{value}`")
+        config.set_option(option, value)
+
+
 @dataclass
 class WaitStep(Step):
     """

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "mxops"
-version = "3.2.0-dev3"
+version = "3.2.0-dev4"
 authors = [
   {name="Etienne Wallet"},
 ]

setup.cfg

@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 3.2.0-dev3
+current_version = 3.2.0-dev4
 parse = (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)(-(?P<release>[^-0-9]+)(?P<build>\d+))?
 serialize = 
 	{major}.{minor}.{patch}-{release}{build}

tests/data/all_steps.yaml

@@ -43,6 +43,10 @@ steps:
       my_var_2: ["alice", "bob"]
       "prefix_%{dynamic_name}_suffix": "%dynamic_value"
 
+  - type: SetConfig
+    option: AUTO_GENERATE_BLOCKS
+    value: "true"
+
   - type: Wait
     for_seconds: 1.2  # optional, defaults to null
     for_blocks: 123   # optional, defaults to null

tests/test_msc_steps.py

@@ -15,7 +15,14 @@
 from mxops.data.execution_data import ScenarioData
 from mxops.execution.scene import execute_step
 from mxops.execution.steps.base import Step
-from mxops.execution.steps import LoopStep, PythonStep, SetVarsStep, WaitStep
+from mxops.common.providers import should_generate_blocks
+from mxops.execution.steps import (
+    LoopStep,
+    PythonStep,
+    SetConfigStep,
+    SetVarsStep,
+    WaitStep,
+)
 from mxops.smart_values import (
     SmartAddress,
     SmartBech32,
@@ -256,6 +263,46 @@ def test_set_vars_step():
     }
 
 
+def test_set_config_step(chain_simulator_network):
+    # Given
+    config = Config.get_config()
+    original_value = config.get("TX_TIMEOUT")
+    step = SetConfigStep(option="TX_TIMEOUT", value="42")
+
+    # When
+    try:
+        step.execute()
+
+        # Then
+        assert config.get("TX_TIMEOUT") == "42"
+    finally:
+        config.set_option("TX_TIMEOUT", original_value)
+
+
+def test_set_config_step_toggles_block_generation(chain_simulator_network):
+    # Given
+    assert should_generate_blocks() is True
+    step = SetConfigStep(option="AUTO_GENERATE_BLOCKS", value="false")
+
+    # When
+    try:
+        step.execute()
+
+        # Then
+        assert should_generate_blocks() is False
+    finally:
+        Config.get_config().set_option("AUTO_GENERATE_BLOCKS", "true")
+
+
+def test_set_config_step_unknown_option_raises():
+    # Given
+    step = SetConfigStep(option="NOT_A_REAL_OPTION", value="42")
+
+    # When / Then
+    with pytest.raises(errors.UnknownConfigOption):
+        step.execute()
+
+
 def test_time_wait_step():
     # Given
     step = WaitStep(for_seconds=0.1)