Random generator extension for VSCode
As for the architecture it seems good to me.

As for the TypeScript I have a few minor suggestions:

Avoid using var, use const or let instead.

function randomIntString(min: number, max: number): string {
    const chance = require('chance').Chance();
    const randomVar: number = chance.integer({
      min: min,
      max: max
    });

    return randomVar.toString();
}


It is also preferable to use let for for-cycle control variables.

for (let x = 0; x &lt; sel.length; x++) {
   // body
}


It would help readability and maintainability if you specified the types of all the arguments of all your functions.

function randomIntString(min: number, max: number): string {
    // body
}


Also prefer using lower case type names for built-in primitive types (e. g. number over Number) when specifying the type of something.

You could specify the IP option type more precisely (asuming you use TypeScript >= 2.0). This will help you prevent typos and also improves readability (the code is more self-documenting):

type IpAddressType = 'ipv4' | 'ipv6';
function randomIP(option?: IpAddressType): string{
    // body stays the same
}


When the property of the object being initialized has the same name as the variable assigned to it you can shorten it like so (see the chance.integer call):

var randomVar: number = chance.integer({
      min,
      max
    });