allow 0 challenge

[volodymyr-basiuk]

No description provided.

[Copilot]

Pull request overview

This PR updates challenge validation so a zero-valued challenge (0 / 0n) is treated as a valid input across auth/on-chain proof generation and circuit input validation.

Changes:

• Allow 0/0n challenges by replacing falsy checks (if (!challenge)) with explicit null/undefined checks.
• Add a regression test ensuring an auth proof request with challenge "0" is handled successfully.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
tests/handlers/auth.test.ts	Extends the auth handler test to include an AuthV3 proof request with a "0" challenge and validates the resulting pub signal.
src/proof/provers/inputs-generator.ts	Updates challenge presence checks to accept 0n and avoid rejecting valid zero challenges.
src/circuits/auth-v2.ts	Updates circuit input validation to accept challenge = 0n.
src/circuits/atomic-query-v3-on-chain.ts	Updates circuit input validation to accept challenge = 0n.

Comments suppressed due to low confidence (1)

src/proof/provers/inputs-generator.ts:257

• In authPrepareInputs, the new null/undefined check allows empty-string challenges (e.g. ''), which will then fail later at BigInt(challenge) with a SyntaxError and a less actionable message than the current explicit "challenge must be provided…" error. Consider treating empty/whitespace strings as missing (or catching BigInt parsing errors) so invalid challenges still raise a clear, consistent error while keeping 0/0n valid.

    let challenge = params.challenge ?? proofReq.params?.challenge;

    if (challenge === null || challenge === undefined) {
      throw new Error('challenge must be provided for auth circuit');
    }

    challenge = BigInt(challenge);

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[Copilot]

This test destructures authRes.authResponse.body.scope by position, which makes it sensitive to any future reordering/filtering of proof responses. To make the test more robust, consider locating responses by id (and/or circuitId) before asserting on pub_signals (e.g., assert the response with id: 3 has challenge 0).