feat(workflows): Improve typings (#4689)

Just improve some typings for simpler usage

packages/workflows/src/helper/pipe.ts

@@ -22,25 +22,23 @@ interface PipelineInput {
   compensate?: WorkflowStepMiddlewareInput | WorkflowStepMiddlewareInput[]
 }
 
-export type WorkflowArguments = {
+export type WorkflowArguments<T = any> = {
   container: MedusaContainer
   payload: unknown
-  data: any
+  data: T
   metadata: TransactionMetadata
   context: Context | SharedContext
 }
 
-export type PipelineHandlerResult<T = undefined> = T extends undefined
-  ? WorkflowStepMiddlewareReturn | WorkflowStepMiddlewareReturn[]
-  : T
-
 export type PipelineHandler<T extends any = undefined> = (
   args: WorkflowArguments
-) => PipelineHandlerResult<T> | Promise<PipelineHandlerResult<T>>
+) => T extends undefined
+  ? Promise<WorkflowStepMiddlewareReturn | WorkflowStepMiddlewareReturn[]>
+  : T
 
-export function pipe(
+export function pipe<T = undefined>(
   input: PipelineInput,
-  ...functions: PipelineHandler[]
+  ...functions: [...PipelineHandler[], PipelineHandler<T>]
 ): WorkflowStepHandler {
   return async ({
     container,
@@ -92,8 +90,10 @@ export function pipe(
             data[action.alias] = action.value
           }
         }
-      } else if (result?.alias) {
-        data[result.alias] = result.value
+      } else if ((result as WorkflowStepMiddlewareReturn)?.alias) {
+        data[(result as WorkflowStepMiddlewareReturn).alias] = (
+          result as WorkflowStepMiddlewareReturn
+        ).value
       }
 
       return result

packages/workflows/src/helper/workflow-export.ts

@@ -56,6 +56,9 @@ export const exportWorkflow = <TData = unknown, TResult = unknown>(
         resultFrom: defaultResult,
       }
     ) => {
+      resultFrom ??= defaultResult
+      throwOnError ??= true
+
       const transaction = await originalRun(
         context?.transactionId ?? ulid(),
         input,