How to randomize buildList results

[ahahn95]

BuildList always returns the same result, even though I'm using faker to try to auto generate values. Is there a way this can be randomized?

Example:

const results = myFactory.buildList(3);

Expected

{
[dayOftheWeek: 'Tuesday'],
[dayOftheWeek: 'Wednesday'],
[dayOftheWeek: 'Friday'],
}

Actual

{
[dayOftheWeek: 'Tuesday'],
[dayOftheWeek: 'Tuesday'],
[dayOftheWeek: 'Tuesday'],
}

[willryan]

can you show me how myFactory is defined? I ran a quick test and buildList generates a new value each time for me.

Without seeing your code for the factory, my first inclination would be to make sure you are using Sync.each(n => generateValue()) and not just generateValue(), and if you are then to figure out if you want/need to use the sequence number to affect the output value.

[ahahn95]

@willryan My factory looks something like this (doesn't match the above example, but you get the idea)

const testFactory = Factory.makeFactory<myInterface>({
randNumber: faker.random.number()
})

const results = testFactory.buildList(5);

[willryan]

ok, yeah, that needs to look like:

const testFactory = Factory.makeFactory<myInterface>({
  randNumber: Sync.each(() => faker.random.number())
})

const results = testFactory.buildList(5);

Without the each() call (imported from the same place as Factory), the value will not be generated on each invocation of build(). each() returns a special Generator object that factory.ts knows means it has to run on each invocation. If a factory is constructed with a value that is not a generator, it just returns that value each time (unless overridden by build()).

[willryan]

on a semi-related note, the callback argument for Sync.each() provides a sequence number which you can use to adjust the output if you want. This can allow for seemingly-random-but-predictable sequences, if need be.

[dayinji]

on a semi-related note, the callback argument for Sync.each() provides a sequence number which you can use to adjust the output if you want. This can allow for seemingly-random-but-predictable sequences, if need be.

I encounter this question, and when I use each() function, a new question was triggered by typescript, which said 'Type 'Generator' is not assignable to type 'number'.'.

How can I deal with it ? Thanks