generate a deterministic uuids using fast-check

💬 Question and Help

I have the following code which I thought would generate a new uuid each time but in a deterministic fashion:

fc.configureGlobal({ seed: 0 });

export const generateUUID4 = (): string => {
  const Uuids = fc.sample(fc.uuidV(4), { numRuns: 1000 });
  const arb = fc
    .infiniteStream(fc.integer({ min: 0, max: 1000 }).noBias().noShrink())
    .map((s) => Uuids[s.next().value]);

  return fc.sample(arb)[0];
};

But this returns the same uuid each time.

The only way I can get it working is like this which is horrific with a global variable:

fc.configureGlobal({ seed: 0 });

const Uuids = fc.sample(fc.uuidV(4), { numRuns: 1000 });
let UuidCounter = 0;

export const generateUUID4 = (): string => {
  const next = Uuids[UuidCounter];

  UuidCounter++;

  return next;
};

[dagda1]

@dubzzz thank you for taking the time to answer. I am not using your lib as intended but these are great answers.

Fast-check is totally awesome and I love how you are using generators. Generators are seriously underused in js.

Thank you, sir! This is great

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.