toolsets to create javascript function enhancers (decorators but more powerful and robust)
npm install @financial-times/n-express-enhancer -D
upgrade a decorator to an enhancer with createEnhancer
import { createEnhancer } from '@financial-times/n-express-enhancer';
// create a decorator with currying
const decorator = targetFunction => (...args) => {
// ...enhancement
return targetFunction(...args);
}
export default createEnhancer(decorator);
Decorators created by currying with arrow functions in ES6 would return a decorated function with undefined
name, as arrow functions are anonymous.
Enhancers upgraded from decorators by createEnhancer
would return an enhanced function inheriting the original name of the target function, which is useful if you need to access the function name and make it available in the next chained enhancer. Furthermore, enhancers can also enhance a function bundle (functions wrapped as methods in an object), handy for reducing repeated lines to enhance a set of functions.
export default enhancer({
someFunctionA: () => {},
someFunctionB: () => {},
});
import { errorToHandler, compose } from '@financial-times/n-express-enhancer';
const someMiddleware = (req, res) => {};
export default compose(errorToHandler, enhancerA, enhancerB)(someMiddleware);
There's an enhancer included in the package that can be used to enhance middleware/controller function in express to next() any error caught to error handler or calling next() on successful middleware execution.
From:
const someMiddleware = (req, res, next) => {
try {
//...throw error if needed
next();
} catch(e) {
next(e);
}
};
export default someMiddleware;
To:
import { errorToHandler } from '@financial-times/n-express-enhancer';
const someMiddleware = (req, res) => {
//...throw error if needed
};
export default errorToHandler(someMiddleware);
If you need to use res.render
in controller, please use enhancedRender
together. This is due to an restriction in express@4.
import { enhancedRender } from '@financial-times/n-express-enhancer';
app.use('/route', enhancedRender, enhancedMiddleware);
n-auto-logger - auto log every operation and action in express
n-auto-metrics - complementary metrics to refelect operations and actions