sunesimonsen/chance-generators

Random generators based on changejs

chance-generators's Issues

Make generator mappers more discoverable

After I've learned about the map method of generators I'm slowly realizing that the mapper functions themselves are very powerful, reusable and composable. I feel we should encourage sharing of such functions, and maybe add some of the most useful ones to core.

We might also want to consider changing the API slightly. it always occurred to me as odd that it was OK to use a Generators instance declared in an outer scope inside the mapper function body (probably because it looks like a side effect and mapper should be "pure"), for example:

var g = new Generators(424);
var equallyLongStrings = g.integer({min:0, max: 10}).map(function (n) {
  return g.array(g.string({length: n}));
});

Would it be possible to eg. pass the Generators instance to the mapper function as the second parameter? I think that would make it easier to put generator mappers into libraries.

Support shrinking on shapes

It should be trivial to do.

Consider introducing an `any` generator.

Something like:

var number = g.pick([
    g.integer({min: -100, max: 100}), g.integer,
    g.floating({min: -100, max: 100}), g.floating
])
var stringNumber = number.map(function (v) { return String(v) })
var anyPrimitive = g.pick([number, g.string, g.pick([
    -0, +0, 0, undefined, null, false, true,
    NaN, Infinity, -Infinity, '', [], stringNumber,
    Number.MAX_SAFE_INTEGER,
    Number.MIN_SAFE_INTEGER,
    Number.MAX_VALUE,
    Number.MIN_VALUE
])])
var any = g.weighted([anyPrimitive, g.array(anyPrimitive)], [10, 1])

It should also be capable of generating random objects and nested arrays.

Project description lists changejs instead of chance.js

Minor nit but the GitHub project description is listed as:
Random generators based on changejs

It should be:
Random generators based on chance.js

Add shrinking to the producer

Investigate if it is possible to shrink the producers by starting with an infinite cycle count. When the producer hits the max cycle count, it starts over.

When you need to shrink you take the current cycle and return a new producer with that as the max cycle count. That way we would shrink towards the beginning of the producer.

How does one establish a seed value for underlying chance library

In previous release one had access to the Generators constructor where a seed value could be supplied. How does one accomplish the same in v3?

Also does one have access the chance instance, a getter or some other means?

Thanks in advance.

Write a section in the documentation about shrinking