So maybe I'm not quite reading the question correctly, but here is all I did.
- Put a sample.json file in the src/webpart directory
var sample:any = require('sample');
In my code, and that populates the sample variable with the json object.
Now, in order to get this to work where you specify the name with a variable, you need to do something a little bit different.
- Create a folder in the src/webpart directory. Let's call it JSON
- Stick all your json files in there
- Load them via
var simple:any = require('json/'+ queryText);
Webpack tries to be smart and bundle all the files it needs, but when it sees a variable rather than a literal, it doesn't really know what to bundle, so it basically bundles a bunch of stuff that it shouldn't, including stuff that isn't valid js, and your bundle is hosed. By putting it into a folder, it scopes down the things that it adds to the bundle, and everything is good.