google-pubsub-emulator

Google Cloud PubSub Emulator

This package helps to start / stop Google Cloud Pub/Sub Emulator with javascript. Perfect to support unit testing when you need the local emulator start in unit / half integration test.

The wrapper sets PUBSUB_EMULATOR_HOST and GCLOUD_PROJECT environment variables.

From 2.0.0 @google-cloud/pubsub moved to the peer dependencies.

#Prerequisites To use the emulator you need to install Google Cloud SDK

#Installation

npm install google-pubsub-emulator --save-dev

#Usage I think the package is the most suitable for unit testing.

const {PubSub} = require('@google-cloud/pubsub');
const Emulator = require('google-pubsub-emulator');

describe('test suit', ()=>{
    process.env.GCLOUD_PROJECT = 'project-id'; // Set the gcloud project Id globally

    let emulator;
    
    before(()=>{
        const options = {
            debug:true, // if you like to see the emulator output
            topics: [
                'projects/project-id/topics/topic-1' // automatically created topic
            ]
        };
        
        emulator = new Emulator(options);
        
        return emulator.start();
    });
    
    after(()=>{
        return emulator.stop();
    });
    
    it('test case', ()=>{
        // your test
    });
})

Options

parameter (type)	default value	description
project (string)	empty	This variable is gcloud project Id. If it is empty, GCLOUD_PROJECT environment variable will be used. Either you should set it directly or the environment variable should be set.
dataDir (string)	empty	The emulator creates a directory where the project files are stored. If it is empty the emulator default value will be used. You could set relative ./directory or absolute path /tmp/dir1/dir2/. If this directory does not exist, it will be created.
clean (boolean)	true	If dataDir value is set and 'clean' value is true then the package deletes the dataDir. The package does not delete the gcloud emulator default directory.
host (string)	empty	If it is empty the'localhost' of google default value is used. It can take the form of a single address (hostname, IPv4, or IPv6)
port (number)	empty	If it is empty the emulator selects a random free port.
debug (boolean)	false	If it is true, it writes the console.logs of the emulator onto the main process console.
topics (array)	[]	If it is contains values then the wrapper create the missing topics. You should set the full identifier of the topic 'projects//topics/'

Methods

name	description
start	Starts the emulator and returns a Promise.
stop	Stops the emulator and returns a Promise.

#License

MIT