prettified

Prettified error handling for Node.js

Prettified error handling for Node.js

npm install prettified

This sample code:

var errors = require('prettified').errors;
try {
    throw new Error("Example error");
} catch(err) {
    errors.print(err);
}

...will print errors using console.error() like this:

/---------------------------------- Error -----------------------------------\
| Error: Example error
+---------------------------------- stack -----------------------------------+
|     at Object.<anonymous> (/home/jhh/git/node-prettified/examples/format.js:3:8)
|     at Module._compile (module.js:449:26)
|     at Object.Module._extensions..js (module.js:467:10)
|     at Module.load (module.js:356:32)
|     at Function.Module._load (module.js:312:12)
|     at Module.runMain (module.js:492:10)
|     at process.startup.processNextTick.process._tickCallback (node.js:244:9)
\----------------------------------------------------------------------------/

The errors.catchfail([opts, ]callback) is a wrapper builder to catch exceptions inside function call.

It returns a function which when invoked calls the callback and passes all original arguments and returns the value untouched.

If exceptions are thrown it will catch them and print them using console.error() or by using a handler specified in opts. Handlers can be functions or Promise A defers (see the q library).

You can simply wrap your existing callback handlers with catchfail like this:

require('fs').exists('test.txt', errors.catchfail(function(exists) {
    console.log('test.txt ' + (exists ? 'exists' : 'not found') );
}));

If you like to handle the error you can pass an error handler as a first argument:

function do_error(err) {
    errors.print(err);
}
setTimeout(errors.catchfail(do_error, function() {
    throw new TypeError("Example error");
}), 200);

You can also use defers from the q library as an error handler:

function test() {
    var defer = require('q').defer();
    setTimeout(errors.catchfail(defer, function() {
        throw new TypeError("Example error");
    }), 200);
    return defer.promise;
}
    
test().fail(function(err) {
    errors.print(err);
});

You can set default error type for uncatched errors like this:

errors.setDefaultError(MySystemError);