andresusandi-pubsub/GooglePubSubBase.js

PubSub library that provides a number of different underlying technologies

const { PubSub } = require('@google-cloud/pubsub');
const { name: packageName } = require('./package.json');

class GooglePubSubBase {
    constructor(projectId, keyFilename, topicName, subscriptionName) {
        if (!projectId)
            throw new Error("projectId is required");
        if (!keyFilename)
            throw new Error("keyFilename is required");
        if (!topicName)
            throw new Error("topicName is required");
        if (!subscriptionName)
            throw new Error("subscriptionName is required");
        
        this.projectId = projectId;
        this.keyFilename = keyFilename;
        this.topicName = topicName;
        this.subscriptionName = subscriptionName;

        // const me = this;
        // console.log(`${packageName}/${me.constructor.name} Initiailizng PubSub for project ${projectId} using authetication file ${keyFilename}`);
        // me.pubSubClient = new PubSub({ projectId, keyFilename });

        // console.log(`${packageName}/${me.constructor.name} Creating new topic named ${topicName}`);
        // me.pubSubClient.createTopic(topicName, (o) => {
        //     console.log(`${packageName}/${me.constructor.name} Topic creation result code: `, o.code);
        //     me.topic = me.pubSubClient.topic(topicName);
        //     console.log(`${packageName}/${me.constructor.name} Creating new subscription named ${subscriptionName}`);
        //     me.pubSubClient.createSubscription(topicName, subscriptionName, (o) => {
        //         console.log(`${packageName}/${me.constructor.name} Subscription creation result code: `, o.code);
        //         me.subscription = me.pubSubClient.subscription(subscriptionName);
        //     });
        // });
    }

    async init() {
        
        console.log(`${packageName}/${this.constructor.name} Initiailizng PubSub for project ${this.projectId} using authetication file ${this.keyFilename}`);
        this.pubSubClient = new PubSub({ projectId: this.projectId, keyFilename: this.keyFilename });

        console.log(`${packageName}/${this.constructor.name} Creating new topic named ${this.topicName}`);
        try {
            const topicResult = await this.pubSubClient.createTopic(this.topicName);
            console.log(`${packageName}/${this.constructor.name} Topic creation result code: `, topicResult.code);
        } catch {
            console.log(`${packageName}/${this.constructor.name} Expected exception for topic ${this.topicName}`);
        }
        this.topic = this.pubSubClient.topic(this.topicName);


        console.log(`${packageName}/${this.constructor.name} Creating new subscription named ${this.subscriptionName}`);
        try {
            const subscriptionResult = await this.pubSubClient.createSubscription(this.topicName, this.subscriptionName);
            console.log(`${packageName}/${this.constructor.name} Subscription creation result code: `, subscriptionResult.code);
        } catch {
            console.log(`${packageName}/${this.constructor.name} Expected exception for subscription ${this.subscriptionName}`);
        }
        this.subscription = this.pubSubClient.subscription(this.subscriptionName);
    }
}

module.exports = GooglePubSubBase;