MVF Servicer Express

Usage

To install the package

Run npm install @mvf/servicer-express

Configuration

Set the following environment variables in your project

• ENVIRONMENT_FILE should be set to one of development | testing | staging | production
• EXPRESS_SERVER_PORT defaults to 80

Express Web

This version of the express integration implements basic express server preset and has no limitations in how the server can be used. By default the preset implements:

• logging
• error handler

To setup this server you will need an entrypoint.ts or equivalent file.

import { Application, DaemonCommand } from '@mvf/servicer';
import { ExpressWeb } from '@mvf/servicer-express';
import { Express, json } from 'express';

const setup = (app: Express) => {
  app.use(json());

  // do whatever you want with the express server setup
}

const setupApplication = async (): Promise<void> => {
  const application = new Application();
  application.addCommands(
    new DaemonCommand(new ExpressWeb(setup),
  );
  await application.run();
};

void setupApplication();

When the above is compiled, the server can be started with node entrypoint.js express-web-daemon command.

Express Api

This is a version of express implementation designed for internal api services and optimized for vertical slice architecture. Configuration of this implementation is deliberately constrained.

Input Constraints

Only json inputs are valid.

Output Constraints

Only json output is valid.

Output will always have the following structure for successful responses, except in the case of status 204 where the output will be empty.

{
  "data": { ... },
}

At the moment output will always have the following structure for error responses. This will likely change in the future due to the fact that it is not good enough for a lot of cases.

{
  "error": "error message",
}

To setup this server you will need an entrypoint.ts or equivalent file. In addition, you will also need to setup EventSources and routes, these are needed for the ExpressApi constructor.

import { Application, DaemonCommand } from '@mvf/servicer';
import { ExpressApi } from '@mvf/servicer-express';
import { routes } from 'Setup/Express';
import { EventSources } from 'EventSources/Express';

const setupApplication = async (): Promise<void> => {
  const application = new Application();
  application.addCommands(
    new DaemonCommand(new ExpressApi(EventSources, routes),
  );
  await application.run();
};

void setupApplication();

When the above is compiled, the server can be started with node entrypoint.js express-api-daemon command.

Contributing

Setup

• Run make to build the container
• Run make shell to enter the container
• Run npm install to install dependencies

Refer to package.json for commands

After merging

After you have merged a PR to master, you need to rebuild and publish your changes.

1. Checkout master git checkout master && git pull
2. Use one of the following make publish commands to publish changes:
   • make publish kind=patch - Use this if your change is a bug fix and is backwards compatible.
   • make publish kind=minor - Use this if your change adds new functionality and is backwards compatible.
   • make publish kind=major - Use this if your change is not backwards compatible.