simplify rendering of task json. move common state json into base class

packages/@aws-cdk/aws-stepfunctions-tasks/lib/lambda/invoke.ts

@@ -2,7 +2,7 @@ import * as iam from '@aws-cdk/aws-iam';
 import * as lambda from '@aws-cdk/aws-lambda';
 import * as sfn from '@aws-cdk/aws-stepfunctions';
 import * as cdk from '@aws-cdk/core';
-import { getResourceArn, TaskStateConfig, taskStateJson, validatePatternSupported } from '../private/task-utils';
+import { integrationResourceArn, validatePatternSupported } from '../private/task-utils';
 
 /**
  * Properties for invoking a Lambda function with LambdaInvoke
@@ -90,18 +90,16 @@ export class LambdaInvoke extends sfn.TaskStateBase {
    * Provides the service integration task configuration
    */
   protected renderTask(): any {
-    const taskStateConfig: TaskStateConfig = {
-      resourceArn: getResourceArn('lambda', 'invoke', this.integrationPattern),
-      parameters: {
+    return {
+      Resource: integrationResourceArn('lambda', 'invoke', this.integrationPattern),
+      Parameters: sfn.FieldUtils.renderObject({
         FunctionName: this.props.lambdaFunction.functionArn,
         Payload: this.props.payload ? this.props.payload.value : sfn.TaskInput.fromDataAt('$').value,
         InvocationType: this.props.invocationType,
         ClientContext: this.props.clientContext,
         Qualifier: this.props.qualifier,
-      },
+      }),
     };
-
-    return taskStateJson(taskStateConfig);
   }
 }
 

packages/@aws-cdk/aws-stepfunctions-tasks/lib/private/task-utils.ts

@@ -1,48 +1,8 @@
 import {
-  FieldUtils,
   IntegrationPattern,
-  renderJsonPath,
-  TaskStateBaseProps,
 } from '@aws-cdk/aws-stepfunctions';
 import { Aws } from '@aws-cdk/core';
 
-/**
- * Represents a service integration call to Step Functions
- */
-export interface TaskStateConfig extends TaskStateBaseProps {
-  /**
-   * The ARN of resource that represents the work to be executed
-   */
-  readonly resourceArn: string;
-
-  /**
-   * Parameters pass a collection of key-value pairs, either static values or
-   * JSON path expressions that select from the input.
-   *
-   * @see https://docs.aws.amazon.com/step-functions/latest/dg/input-output-inputpath-params.html#input-output-parameters
-   *
-   * @default - No parameters
-   */
-  readonly parameters?: { [name: string]: any };
-}
-
-/**
- * Generates the State JSON to define a task state
- */
-export function taskStateJson(config: TaskStateConfig): any {
-  return {
-    Type: 'Task',
-    Comment: config.comment,
-    Resource: config.resourceArn,
-    Parameters: config.parameters && FieldUtils.renderObject(config.parameters),
-    TimeoutSeconds: config.timeout?.toSeconds(),
-    HeartbeatSeconds: config.heartbeat?.toSeconds(),
-    InputPath: renderJsonPath(config.inputPath),
-    OutputPath: renderJsonPath(config.outputPath),
-    ResultPath: renderJsonPath(config.resultPath),
-  };
-}
-
 /**
  * Verifies that a validation pattern is supported for a service integration
  *
@@ -60,15 +20,16 @@ export function validatePatternSupported(integrationPattern: IntegrationPattern,
  *
  * @see https://docs.aws.amazon.com/step-functions/latest/dg/connect-to-resource.html
  */
-const resourceArnSuffix = new Map<IntegrationPattern, string>();
-resourceArnSuffix.set(IntegrationPattern.REQUEST_RESPONSE, '');
-resourceArnSuffix.set(IntegrationPattern.RUN_JOB, '.sync');
-resourceArnSuffix.set(IntegrationPattern.WAIT_FOR_TASK_TOKEN, '.waitForTaskToken');
+const resourceArnSuffix: Record<IntegrationPattern, string> = {
+  [IntegrationPattern.REQUEST_RESPONSE]: '',
+  [IntegrationPattern.RUN_JOB]: '.sync',
+  [IntegrationPattern.WAIT_FOR_TASK_TOKEN]: '.waitForTaskToken',
+};
 
-export function getResourceArn(service: string, api: string, integrationPattern: IntegrationPattern): string {
+export function integrationResourceArn(service: string, api: string, integrationPattern: IntegrationPattern): string {
   if (!service || !api) {
     throw new Error("Both 'service' and 'api' must be provided to build the resource ARN.");
   }
   return `arn:${Aws.PARTITION}:states:::${service}:${api}` +
-        (integrationPattern ? resourceArnSuffix.get(integrationPattern) : '');
+        (integrationPattern ? resourceArnSuffix[integrationPattern] : '');
 }

packages/@aws-cdk/aws-stepfunctions-tasks/lib/sns/publish.ts

@@ -2,7 +2,7 @@ import * as iam from '@aws-cdk/aws-iam';
 import * as sns from '@aws-cdk/aws-sns';
 import * as sfn from '@aws-cdk/aws-stepfunctions';
 import * as cdk from '@aws-cdk/core';
-import { getResourceArn, TaskStateConfig, taskStateJson, validatePatternSupported } from '../private/task-utils';
+import { integrationResourceArn, validatePatternSupported } from '../private/task-utils';
 
 /**
  * Properties for PublishTask
@@ -87,16 +87,14 @@ export class SnsPublish extends sfn.TaskStateBase {
   }
 
   protected renderTask(): any {
-    const taskConfig: TaskStateConfig = {
-      resourceArn: getResourceArn('sns', 'publish', this.integrationPattern),
-      parameters: {
+    return {
+      Resource: integrationResourceArn('sns', 'publish', this.integrationPattern),
+      Parameters: sfn.FieldUtils.renderObject({
         TopicArn: this.props.topic.topicArn,
         Message: this.props.message.value,
         MessageStructure: this.props.messagePerSubscriptionType ? 'json' : undefined,
         Subject: this.props.subject,
-      },
+      }),
     };
-
-    return taskStateJson(taskConfig);
   }
 }

packages/@aws-cdk/aws-stepfunctions-tasks/lib/sqs/send-message.ts

@@ -2,7 +2,7 @@ import * as iam from '@aws-cdk/aws-iam';
 import * as sqs from '@aws-cdk/aws-sqs';
 import * as sfn from '@aws-cdk/aws-stepfunctions';
 import * as cdk from '@aws-cdk/core';
-import { getResourceArn, TaskStateConfig, taskStateJson, validatePatternSupported } from '../private/task-utils';
+import { integrationResourceArn, validatePatternSupported } from '../private/task-utils';
 
 /**
  * Properties for SendMessageTask
@@ -92,17 +92,15 @@ export class SqsSendMessage extends sfn.TaskStateBase {
   }
 
   protected renderTask(): any {
-    const taskConfig: TaskStateConfig = {
-      resourceArn: getResourceArn('sqs', 'sendMessage', this.integrationPattern),
-      parameters: {
+    return {
+      Resource: integrationResourceArn('sqs', 'sendMessage', this.integrationPattern),
+      Parameters: sfn.FieldUtils.renderObject({
         QueueUrl: this.props.queue.queueUrl,
         MessageBody: this.props.messageBody.value,
         DelaySeconds: this.props.delay && this.props.delay.toSeconds(),
         MessageDeduplicationId: this.props.messageDeduplicationId,
         MessageGroupId: this.props.messageGroupId,
-      },
+      }),
     };
-
-    return taskStateJson(taskConfig);
   }
 }

packages/@aws-cdk/aws-stepfunctions/lib/states/task-base.ts

@@ -3,7 +3,7 @@ import * as iam from '@aws-cdk/aws-iam';
 import { Chain } from '../chain';
 import { StateGraph } from '../state-graph';
 import { CatchProps, IChainable, INextable, RetryProps } from '../types';
-import { State } from './state';
+import { renderJsonPath, State } from './state';
 
 import * as cdk from '@aws-cdk/core';
 
@@ -89,12 +89,17 @@ export abstract class TaskStateBase extends State implements INextable {
 
   public readonly endStates: INextable[];
 
-  protected abstract readonly taskMetrics: TaskMetricsConfig | undefined;
-  protected abstract readonly taskPolicies: iam.PolicyStatement[] | undefined;
+  protected abstract readonly taskMetrics?: TaskMetricsConfig;
+  protected abstract readonly taskPolicies?: iam.PolicyStatement[];
+
+  private readonly timeout?: cdk.Duration;
+  private readonly heartbeat?: cdk.Duration;
 
   constructor(scope: cdk.Construct, id: string, props: TaskStateBaseProps) {
     super(scope, id, props);
     this.endStates = [this];
+    this.timeout = props.timeout;
+    this.heartbeat = props.heartbeat;
   }
 
   /**
@@ -134,6 +139,7 @@ export abstract class TaskStateBase extends State implements INextable {
     return {
       ...this.renderNextEnd(),
       ...this.renderRetryCatch(),
+      ...this.renderTaskBase(),
       ...this.renderTask(),
     };
   }
@@ -249,6 +255,18 @@ export abstract class TaskStateBase extends State implements INextable {
     }
     return this.metric(prefix + suffix, props);
   }
+
+  private renderTaskBase() {
+    return {
+      Type: 'Task',
+      Comment: this.comment,
+      TimeoutSeconds: this.timeout?.toSeconds(),
+      HeartbeatSeconds: this.heartbeat?.toSeconds(),
+      InputPath: renderJsonPath(this.inputPath),
+      OutputPath: renderJsonPath(this.outputPath),
+      ResultPath: renderJsonPath(this.resultPath),
+    };
+  }
 }
 
 /**