• Thomas Randolph's avatar
    Add a seedable UUIDv4 generator · 1f241d28
    Thomas Randolph authored
    Most UUID generators assume that you want fully
    random UUIDs. In most cases, this is true.
    
    The `uuid` package allows
    a consumer to pass in `random` values (an array
    of 16 numbers 0-255), or a generator that outputs
    16 random bytes.
    
    This is our hook into being able to provide
    "random" values. We just need a way to get
    "random" values that are actually random in
    most cases, but that we can control if we want
    to.
    
    Enter: the Mersenne Twister.
    Mersenne Twisters can be seeded with a number
    to start. They will derive all of their future twisted
    states from that initial seed. So: we still get
    "randomness," but we can also seed it to make
    the output deterministic.
    
    This `random.js` file outputs a single function
    (for now) called `uuids` that will generate a
    random UUIDv4 string or - if provided seeds -
    will generate the correct resulting UUIDv4
    given those seeds.
    
    Consumers can request multiple values
    to avoid having to constantly call the function
    and/or constantly reconstruct the internal
    Twister.
    1f241d28
uuids_spec.js 3.14 KB