Lab: Build a process using SAGA pattern in Aletyx Enterprise Build of Kogito and Drools 10.1.0-aletyx

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Lab Overview

1. Reserve Product – Reserve stock for the order.
2. Process Payment – Process the payment.
3. Confirm Order – Final confirmation task.

• Cancel Product Reservation
• Cancel Payment

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Supporting Files

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StockService.java

• reserveStock(): Attempts to reserve stock and uses the MockService to simulate success or failure.
• cancelStock(): Cancels the reserved stock if a failure occurs.

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PaymentService.java

• processPayment(): Processes the payment for the order. The result is simulated through the MockService.
• cancelPayment(): Cancels the payment if the process fails.

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OrderService.java

• success(): Logs and returns a success response when the order is completed without errors.
• failure(): Logs and returns an error response when the order process fails.

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Response.java

• Type: Enum representing SUCCESS or ERROR responses.
• Utility methods like success(), error(), and isSuccess() simplify response management.

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MockService.java

• execute(): Checks if the current service should fail based on the failClass parameter. It returns either a SUCCESS or ERROR response without throwing exceptions. This supports the data-driven flow approach by allowing gateways to handle decisions based on response data.

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Instructions

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Step 1: Clone the Repository

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Step 2: Import the Project

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Step 3: Create the BPMN file

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Step 4: Create the process diagram

1. Start Event: Initiates the order process.
2. Reserve Product Task Interface: ai.aletyx.kie.workshop.saga.StockService Operation: reserveStock Variables - Input Mapping:

   Name	Data Type	Source
   param1	String	orderId
   param2	String	failService

   Variables - Output Mapping:

   Name	Data Type	Target
   result	Response [ai.aletyx.kie.workshop.saga]	stockResponse

3. Exclusive Gateway: We’ll check if the Reserve was successfull or not.
   • On Fail
     return !stockResponse.isSuccess();
     
     3.1. Create an Inclusive Gateway to consolidate actions 3.2. Create a Order Failed Task Interface: ai.aletyx.kie.workshop.saga.OrderService Operation: failure Variables - Input Mapping:

     Name	Data Type	Source
     param1	String	orderId

     Variables - Output Mapping:

     Name	Data Type	Target
     result	Response [ai.aletyx.kie.workshop.saga]	orderResponse

     3.3. Create an End Compensation Node
   • On Success:
     return stockResponse.isSuccess();
     
     3.4. Process Payment Task Interface: ai.aletyx.kie.workshop.saga.PaymentService Operation: processPayment Variables - Input Mapping:

     Name	Data Type	Source
     param1	String	orderId
     param2	String	failService

     Variables - Output Mapping:

     Name	Data Type	Target
     result	Response [ai.aletyx.kie.workshop.saga]	paymentResponse

     3.5. Exclusive Gateway: We’ll check if the Payment was successfull or not.
     • On Fail:
       return !paymentResponse.isSuccess();
       
       3.5.1 Connect it to the Inclusive Gateway for the Order Failed Task
     • On Success:
       return paymentResponse.isSuccess();
       
       3.5.2. Confirm Order Task Interface: ai.aletyx.kie.workshop.saga.OrderService Operation: success Variables - Input Mapping:

       Name	Data Type	Source
       param1	String	orderId

       Variables - Output Mapping:

       Name	Data Type	Target
       result	Response [ai.aletyx.kie.workshop.saga]	orderResponse

       3.5.3. End event
4. Add Compensatory Tasks 5.1. Drag a compensatory catch event from palette and bound it to Reserve Product 5.2. Select the compensatory node, using the context menu, create a new task and name it Cancel Product Reservation, and change it to Service Task Interface: ai.aletyx.kie.workshop.saga.StockService Operation: cancelStock Variables - Input Mapping:

   Name	Data Type	Source
   param1	String	orderId

   5.3. Drag a compensatory catch event from palette and bound it to Process Payment 5.4. Select the compensatory node, using the context menu, create a new task and name it Cancel Payment, and change it to Service Task Interface: ai.aletyx.kie.workshop.saga.PaymentService Operation: cancelPayment Variables - Input Mapping:

   Name	Data Type	Source
   param1	String	orderId

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Step 5: Test the Process

• Run the process in different scenarios by passing the failService parameter to simulate success and failure for specific tasks.
• Verify that compensatory actions are executed when failures occur and that the final task correctly reflects the process outcome.

import org.junit.jupiter.api.Test;

import io.quarkus.test.junit.QuarkusTest;
import io.restassured.http.ContentType;
import io.restassured.response.ExtractableResponse;
import io.restassured.response.Response;

import static io.restassured.RestAssured.given;
import static org.assertj.core.api.Assertions.assertThat;
import static org.hamcrest.CoreMatchers.notNullValue;

@QuarkusTest
public class TestProcessOrder {

    public static final String ORDER_ID = "03e6cf79-3301-434b-b5e1-d6899b5639aa";

    @Test
    public void testOrderSuccess() {
        String payload = "{\n" +
                "    \"orderId\": \"" + ORDER_ID + "\"\n" +
                "}";
        ExtractableResponse<Response> response = createOrder(payload);
        response.path("id");
        assertThat(response.<String> path("paymentResponse.type")).isEqualTo("SUCCESS");
        assertThat(response.<String> path("stockResponse.type")).isEqualTo("SUCCESS");
        assertThat(response.<String> path("orderResponse.type")).isEqualTo("SUCCESS");
        assertThat(response.<String> path("orderResponse.resourceId")).isEqualTo(ORDER_ID);
    }

    @Test
    public void testOrderFailure() {
        String payload = "{\n" +
                "    \"orderId\": \"" + ORDER_ID + "\",\n" +
                "    \"failService\" : \"PaymentService\"\n" +
                "}";
        ExtractableResponse<Response> response = createOrder(payload);
        response.path("id");
        assertThat(response.<String> path("stockResponse.type")).isEqualTo("SUCCESS");
        assertThat(response.<String> path("paymentResponse.type")).isEqualTo("ERROR");
        assertThat(response.<String> path("orderResponse.type")).isEqualTo("ERROR");
        assertThat(response.<String> path("orderResponse.resourceId")).isEqualTo(ORDER_ID);
    }

    private ExtractableResponse<Response> createOrder(String payload) {
        ExtractableResponse<Response> response = given()
                .contentType(ContentType.JSON)
                .accept(ContentType.JSON)
                .body(payload)
                .when()
                .post("/order")
                .then()
                .statusCode(201)
                .header("Location", notNullValue())
                .extract();
        return response;
    }
}