fix(stepfunctions-tasks): confusion between multiple ways to run a La…

…mbda (#6796)

The InvokeFunction Step Functions task is being marked as deprecated. It represents the legacy way to represent Lambda functions in Step Functions

The RunLambda task represents the recommended way to invoke Lambdas in Step Functions.
see: https://docs.aws.amazon.com/step-functions/latest/dg/connect-lambda.html

Examples in the README have been updated to use RunLambdaTask

Closes #4801

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

@@ -4,6 +4,8 @@ import * as sfn from '@aws-cdk/aws-stepfunctions';
 
 /**
  * Properties for InvokeFunction
+ *
+ * @deprecated use `RunLambdaTask`
  */
 export interface InvokeFunctionProps {
   /**
@@ -22,6 +24,8 @@ export interface InvokeFunctionProps {
  * The Lambda function Arn is defined as Resource in the state machine definition.
  *
  * OUTPUT: the output of this task is the return value of the Lambda Function.
+ *
+ * @deprecated Use `RunLambdaTask`
  */
 export class InvokeFunction implements sfn.IStepFunctionsTask {
   constructor(private readonly lambdaFunction: lambda.IFunction, private readonly props: InvokeFunctionProps = {}) {

packages/@aws-cdk/aws-stepfunctions/README.md

@@ -35,7 +35,9 @@ const submitLambda = new lambda.Function(this, 'SubmitLambda', { ... });
 const getStatusLambda = new lambda.Function(this, 'CheckLambda', { ... });
 
 const submitJob = new sfn.Task(this, 'Submit Job', {
-    task: new tasks.InvokeFunction(submitLambda),
+    task: new tasks.RunLambdaTask(submitLambda, {
+      integrationPattern: sfn.ServiceIntegrationPattern.WAIT_FOR_TASK_TOKEN,
+    }),
     // Put Lambda's result here in the execution's state object
     resultPath: '$.guid',
 });
@@ -45,7 +47,9 @@ const waitX = new sfn.Wait(this, 'Wait X Seconds', {
 });
 
 const getStatus = new sfn.Task(this, 'Get Job Status', {
-    task: new tasks.InvokeFunction(getStatusLambda),
+    task: new tasks.RunLambdaTask(getStatusLambda, {
+      integrationPattern: sfn.ServiceIntegrationPattern.WAIT_FOR_TASK_TOKEN,
+    }),
     // Pass just the field named "guid" into the Lambda, put the
     // Lambda's result in a field called "status"
     inputPath: '$.guid',
@@ -58,7 +62,9 @@ const jobFailed = new sfn.Fail(this, 'Job Failed', {
 });
 
 const finalStatus = new sfn.Task(this, 'Get Final Job Status', {
-    task: new tasks.InvokeFunction(getStatusLambda),
+    task: new tasks.RunLambdaTask(getStatusLambda, {
+      integrationPattern: sfn.ServiceIntegrationPattern.WAIT_FOR_TASK_TOKEN,
+    }),
     // Use "guid" field as input, output of the Lambda becomes the
     // entire state machine output.
     inputPath: '$.guid',
@@ -127,7 +133,6 @@ couple of the tasks available are:
 
 * `tasks.InvokeActivity` -- start an Activity (Activities represent a work
   queue that you poll on a compute fleet you manage yourself)
-* `tasks.InvokeFunction` -- invoke a Lambda function with function ARN
 * `tasks.RunBatchJob` -- run a Batch job
 * `tasks.RunLambdaTask` -- call Lambda as integrated service with magic ARN
 * `tasks.RunGlueJobTask` -- call Glue Job as integrated service
@@ -140,9 +145,9 @@ couple of the tasks available are:
 * `tasks.StartExecution` -- call StartExecution to a state machine of Step Functions
 * `tasks.EvaluateExpression` -- evaluate an expression referencing state paths
 
-Except `tasks.InvokeActivity` and `tasks.InvokeFunction`, the [service integration
+Except `tasks.InvokeActivity`, the [service integration
 pattern](https://docs.aws.amazon.com/step-functions/latest/dg/connect-to-resource.html)
-(`integrationPattern`) are supposed to be given as parameter when customers want
+(`integrationPattern`) is supposed to be provided as a parameter when customers want
 to call integrated services within a Task state. The default value is `FIRE_AND_FORGET`.
 
 #### Task parameters from the state json
@@ -155,29 +160,7 @@ such as `Data.stringAt()`.
 If so, the value is taken from the indicated location in the state JSON,
 similar to (for example) `inputPath`.
 
-#### Lambda example - InvokeFunction
-
-```ts
-const task = new sfn.Task(this, 'Invoke1', {
-    task: new tasks.InvokeFunction(myLambda),
-    inputPath: '$.input',
-    timeout: Duration.minutes(5),
-});
-
-// Add a retry policy
-task.addRetry({
-    interval: Duration.seconds(5),
-    maxAttempts: 10
-});
-
-// Add an error handler
-task.addCatch(errorHandlerState);
-
-// Set the next state
-task.next(nextState);
-```
-
-#### Lambda example - RunLambdaTask
+#### Lambda example
 
 ```ts
   const task = new sfn.Task(stack, 'Invoke2', {