Google Cloud Datastore Emulator
This package helps to start / stop Google Datatstore Emulator with javascript. From 1.1.0 also could usable with google/cloud-sdk docker image. The wrapper automatically pull the image is not exists on the host, but I suggest to pull the image in the 'before_test' section in the CI script Important: Be careful with the timeouts, need time to pull the image, start and stop the container.
Perfect to support unit testing where the persistent layer is the gcloud Datastore.
The wrapper sets DATASTORE_EMULATOR_HOST and DATASTORE_PROJECT_ID environment variables.
Prerequisites
To use the emulator locally you need to install Google Cloud SDK or with Docker you need to install Docker host
Installation
npm install google-datastore-emulator --save-dev
Usage
I think the package is the most suitable for unit testing.
const datastore = require('@google-cloud/datastore');
const Emulator = require('google-datastore-emulator');
describe('test suit', ()=>{
process.env.GCLOUD_PROJECT = 'project-id'; // Set the datastore project Id globally
let emulator;
before(()=>{
const options = {
useDocker: true // if you need docker image
};
emulator = new Emulator(options);
return emulator.start();
});
after(()=>{
return emulator.stop();
});
it('test case', ()=>{
// your test
});
})Options
| parameter (type) | default value | description |
|---|---|---|
| project (string) | test | This variable is datastore project Id. |
| storeOnDisk (boolean) | false | The datastore either persists the entities on disk or not. |
| 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. Bug : With linux Docker host don't delete the folder |
| 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) | localhost | 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. |
| consistency (string) | '1.0' | The consistency level of the Datastore Emulator. More details |
| useDocker (boolean) | false | If it is true, it use docker image to run emulator instead of locally installed version. |
| dockerImage (string) | 'google/cloud-sdk:latest' | This image will be use by docker. The default: google/cloud-sdk:latest |
Methods
| name | description |
|---|---|
| start | Starts the emulator and returns a Promise. |
| stop | Stops the emulator and returns a Promise. |
License
MIT