README
Prettified error handling for Node.js
Installing
npm install prettified
Pretty printing exceptions
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)
\----------------------------------------------------------------------------/
Catch errors inside callbacks
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).
Example 1
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') );
}));
Example 2 -- with an error handler
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);
Example 3 -- with defers as an error handler
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);
});
Setting default error type
You can set default error type for uncatched errors like this:
errors.setDefaultError(MySystemError);