I've been playing around with JS to try and find the most elegant way to do type checking through Express middleware.
I like this format, but its farrr from something that you should use.
Take this route in Express:
app.get('/:id',function(req,res){
return res.sendStatus(200)
})If you want to assert that req.params.id should be an integer, you'd add type.int('params.id') as middleware.
Here's what the resulting route would look like:
app.get('/:id',type.int('params.something.id'),function(req,res){
return res.sendStatus(200)
})Out of the box, Typedot supports these types:
- Integer:
type.int(someVar) - String:
type.string(someVar) - Object:
type.object(someVar) - Char:
type.char(someVar)
Because Express (and HTTP, for that matter) treats params, query strings, et. al as strings, the type checking done by Typedot involves heavy type casting. If it can logically be cast to the expected type, Typedot will try to make that happen.
In practice:
type.int('1') // true
type.int(1) // true
type.int(1.0) //trueIf you need stricter checks for a specific type, I'll be adding custom types soon enough.
You may have noticed that the API for Typedot feels like it shouldn't work. Aren't int, string, etc. reserved words? Weirdly, no! As of ES 5/6, a bunch of reserved words in traditional C-derived languages are freed in JS. But this is still JS, and as such, you should have no expectation that this won't cause problems in different environments.
So don't use Typedot in the browser. In fact, I haven't tested it on any Node version <8.2.0 so you should probably be using Node 8 just to be safe.
Why would you want to use an Express type-checking middleware library in the browser? I have no idea. What I do know, is that you shouldn't.
Tests, like the module itself, are a work in progress. You can run them with npm test.
Here's what I'd like to add soon-ish:
- More types to check
- Support for custom types
- Better Documentation
- Published examples
- Type conversion