smart-saga-pattern/dist/choreography/SagaCoordinator.js

A library implementing the Saga pattern for microservice architecture

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.SagaCoordinator = void 0;
const Saga_1 = require("../core/Saga");
const types_1 = require("../types");
/**
 * Coordinates a choreography-based Saga
 */
class SagaCoordinator extends Saga_1.Saga {
    /**
     * Creates a new SagaCoordinator
     * @param participant Saga participant for communication
     * @param options Options for the coordinator
     * @param stateStore Optional state store for persistence
     */
    constructor(participant, options, stateStore) {
        super(options);
        this.participant = participant;
        this.stateStore = stateStore;
        // Set up event handlers
        this.setupEventHandlers();
    }
    /**
     * Executes the Saga
     * @param initialData Initial data for the Saga
     */
    async execute(initialData) {
        try {
            // Update context with initial data
            if (initialData) {
                this.updateContext(initialData);
            }
            // Save initial state if state store is provided
            if (this.stateStore) {
                await this.stateStore.save(this.getId(), this.getContext());
            }
            // Set up completion promise
            this.completionPromise = new Promise((resolve, reject) => {
                this.completionResolve = resolve;
                this.completionReject = reject;
            });
            // Start the Saga by publishing the initial event
            await this.participant.publish('SAGA_STARTED', this.context.data, this.getId());
            // Set status to executing
            this.setStatus(types_1.SagaStatus.EXECUTING);
            // Update state store if provided
            if (this.stateStore) {
                await this.stateStore.update(this.getId(), this.context);
            }
            // Wait for completion
            return await this.completionPromise;
        }
        catch (error) {
            this.setStatus(types_1.SagaStatus.FAILED, error instanceof Error ? error.message : String(error));
            // Update state store if provided
            if (this.stateStore) {
                await this.stateStore.update(this.getId(), this.context);
            }
            return this.getContext();
        }
    }
    /**
     * Compensates the Saga (rolls back)
     */
    async compensate() {
        try {
            this.setStatus(types_1.SagaStatus.COMPENSATING);
            // Update state store if provided
            if (this.stateStore) {
                await this.stateStore.update(this.getId(), this.context);
            }
            // Publish compensation event
            await this.participant.publish('SAGA_COMPENSATE', this.context.data, this.getId());
            // Wait for completion
            return await this.completionPromise;
        }
        catch (error) {
            this.setStatus(types_1.SagaStatus.COMPENSATION_FAILED, error instanceof Error ? error.message : String(error));
            // Update state store if provided
            if (this.stateStore) {
                await this.stateStore.update(this.getId(), this.context);
            }
            return this.getContext();
        }
    }
    /**
     * Sets up event handlers for the coordinator
     */
    setupEventHandlers() {
        // Handle saga completion
        this.participant.on('SAGA_COMPLETED', async (event) => {
            this.setStatus(types_1.SagaStatus.COMPLETED);
            // Update context with event payload
            this.updateContext(event.payload);
            // Update state store if provided
            if (this.stateStore) {
                await this.stateStore.update(this.getId(), this.context);
            }
            // Resolve completion promise
            if (this.completionResolve) {
                this.completionResolve(this.getContext());
            }
        });
        // Handle saga failure
        this.participant.on('SAGA_FAILED', async (event) => {
            this.setStatus(types_1.SagaStatus.FAILED, event.payload.error);
            // Update context with event payload
            this.updateContext(event.payload);
            // Update state store if provided
            if (this.stateStore) {
                await this.stateStore.update(this.getId(), this.context);
            }
            // Reject completion promise
            if (this.completionReject) {
                this.completionReject(new Error(event.payload.error));
            }
        });
        // Handle saga compensation completed
        this.participant.on('SAGA_COMPENSATED', async (event) => {
            this.setStatus(types_1.SagaStatus.COMPENSATED);
            // Update context with event payload
            this.updateContext(event.payload);
            // Update state store if provided
            if (this.stateStore) {
                await this.stateStore.update(this.getId(), this.context);
            }
            // Resolve completion promise
            if (this.completionResolve) {
                this.completionResolve(this.getContext());
            }
        });
        // Handle saga compensation failed
        this.participant.on('SAGA_COMPENSATION_FAILED', async (event) => {
            this.setStatus(types_1.SagaStatus.COMPENSATION_FAILED, event.payload.error);
            // Update context with event payload
            this.updateContext(event.payload);
            // Update state store if provided
            if (this.stateStore) {
                await this.stateStore.update(this.getId(), this.context);
            }
            // Reject completion promise
            if (this.completionReject) {
                this.completionReject(new Error(event.payload.error));
            }
        });
    }
}
exports.SagaCoordinator = SagaCoordinator;