Allow async getStepStartStates in InvocationConfig

[austinkelleher]

Problem

Sometimes permissions for a given config are not known at the beginning of an integration execution. These permissions may ultimately decide which steps are able to be executed. For example, in the Google Cloud integration, we do not know strictly from the config passed to the integration whether specific APIs have been enabled in the Google Cloud account or whether the integration has the correct scopes for steps to be invoked. As past of the getStepStartStates function in the Google Cloud integration, we would make a request to fetch this information and properly decide which steps can be invoked ahead of time.

The current value of the return type of getStepStartStates can be found here: https://github.com/JupiterOne/sdk/blob/master/packages/integration-sdk-core/src/types/config.ts#L16

export interface InvocationConfig<
  TExecutionContext extends ExecutionContext,
  TStepExecutionContext extends StepExecutionContext
> {
  getStepStartStates?: GetStepStartStatesFunction<TExecutionContext>;
 ...
}

Proposal

Change implementation of getStepStartStates in InvocationConfig to support sync and async methods:

export interface InvocationConfig<
  TExecutionContext extends ExecutionContext,
  TStepExecutionContext extends StepExecutionContext
> {
  validateInvocation?: InvocationValidationFunction<TExecutionContext>;
  getStepStartStates?: GetStepStartStatesFunction<TExecutionContext> | Promise<GetStepStartStatesFunction<TExecutionContext>>;
  integrationSteps: Step<TStepExecutionContext>[];
}

[aiwilliams]

Oh, yeah, this should definitely be capable of async behavior.

Wouldn't the change be in the function type declaration?

export type GetStepStartStatesFunction<T extends ExecutionContext> = (
  context: T,
) => StepStartStates | Promise<StepStartStates>;

[austinkelleher]

Yup I didn't look closely at the code yet. Just wanted to get the proposal out there. Thanks.