How can I hot reload a controller in koa?

by elise_daugherty , in category: Javascript , 2 months ago

How can I hot reload a controller in koa?

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1 answer

by edmond_brakus , 2 months ago

@elise_daugherty 

To achieve hot reloading in Koa for a controller, you can use the koa-router npm module and the import fresh from 'import-fresh' to reload the controller module.


Here's an example of how you can implement hot reloading for a Koa controller:

  1. Install the necessary dependencies:
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npm install koa koa-router import-fresh


  1. Create an index.js file to initialize your Koa application:
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const Koa = require('koa');
const Router = require('koa-router');

const app = new Koa();
const router = new Router();

app.use(router.routes());

app.listen(3000, () => {
  console.log('Server listening on port 3000');
});


  1. Create your controller file exampleController.js:
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const exampleController = (ctx) => {
  ctx.body = 'Hello, World!';
};

module.exports = exampleController;


  1. Modify the index.js file to load the controller dynamically using import-fresh:
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const Koa = require('koa');
const Router = require('koa-router');
const fresh = require('import-fresh');

const app = new Koa();
const router = new Router();

let controller = fresh('./exampleController'); // Import the controller

router.get('/', async (ctx) => {
  controller(ctx); // Call the controller
});

app.use(router.routes());

app.listen(3000, () => {
  console.log('Server listening on port 3000');
});

// Watch for changes in the controller file and reload it
if (module.hot) {
  module.hot.accept('./exampleController', () => {
    controller = fresh('./exampleController');
    console.log('Controller reloaded');
  });
}


  1. Run your Koa application using nodemon:
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nodemon index.js


Now, whenever you make changes to your exampleController.js file, nodemon will trigger a reload, allowing your changes to take effect without stopping and restarting the Koa server.