Easy feature toggling for connect-based (Express, Restify, etc.) handlers, as well as for arbitrary blocks of code.

• Designed for Node.js usage only.
• Currently only has support for connect-like handlers. Arbitrary blocks of code coming in the future.

Give it a predicate and a connect-based handler, and it will return the handler you want.

var might = require('might');
var handlers = require('./handlers');
var config = require('./config');

server.get('/',
           might.handleIf(config.useNewFeature, handlers.newFeature),
           handlers.theVanillaStuff);

If config.useNewFeature equals true, then the route mounting is equivalent to this:

server.get('/',
           handlers.newFeature,
           handlers.theVanillaStuff);

But if config.useNewFeature equals false, then under the hood, this is what gets mounted:

server.get('/',
           function noMatchNoOp (req, res, next) {
             return next();
           },
           handlers.theVanillaStuff);

If the predicate is true, you will get the original handler; otherwise you will get an alternate.

• predicate (required, Boolean | Object | Function) :: If an object, it will iterate through the keys and see if they all match those in process.env; if a function, its return value will be coerced to a boolean.
• handler (required, Function) :: The connect-based handler that will be used if predicate is true.
• alternate (optional, Function) :: If you don't want a noop passthrough handler, you can pass another one in here. Will throw an error if the alternate handler is not a valid connect-based handler.