fix(keys): accept uppercase 0X prefix in isHexString

[kutluhaneth46]

Summary

• isHexString only stripped a lowercase 0x prefix, while hexStringToBytes already accepts 0X….
• Make the guard strip the prefix case-insensitively so values the decoder accepts also pass the type guard.
• Add a regression test for 0XABCDEF.

This is distinct from #161 (bare 0x / empty body); that PR does not make the prefix check case-insensitive.

Test plan

• pnpm --filter @agentcommercekit/keys exec vitest run src/encoding/hex.test.ts
• Confirm isHexString('0XABCDEF') === true
• Confirm invalid hex still returns false

Made with Cursor

Summary by CodeRabbit

• Bug Fixes

  • Hex string validation now accepts both lowercase 0x and uppercase 0X prefixes, matching hex string conversion behavior.

• Tests

  • Added coverage for valid hexadecimal strings using the uppercase 0X prefix.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Team

Run ID: c1179500-0e65-4561-a238-1d13bb912a8f

📥 Commits

Reviewing files that changed from the base of the PR and between 7d23f83 and 72a7ce5.

📒 Files selected for processing (3)

• .changeset/is-hex-string-uppercase-prefix.md
• packages/keys/src/encoding/hex.test.ts
• packages/keys/src/encoding/hex.ts

Included review availability: Your plan provides up to 2 included reviews per hour; 0 remain after this review.

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Walkthrough

isHexString now accepts uppercase 0X prefixes by normalizing input before validation. A test covers this case, and a changeset declares a patch release for @agentcommercekit/keys.

Changes

Hex prefix validation

Layer / File(s)	Summary
Accept uppercase hex prefixes packages/keys/src/encoding/hex.ts, packages/keys/src/encoding/hex.test.ts, .changeset/is-hex-string-uppercase-prefix.md	isHexString now accepts 0X prefixes. The test verifies 0XABCDEF. The changeset documents the patch release.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Merge Risk: ⚪ Minimal · up to b7442

This change makes uppercase 0X-prefixed hexadecimal strings valid in isHexString, matching existing decoder behavior. The new behavior is directly covered by a regression test, with no remaining current-head merge risk identified.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: isHexString now accepts an uppercase 0X prefix.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files. (1 skipped: 1 …
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files. (1 skipped: 1 unsupported.)

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[venables]

Thank you for the contribution. What isHexString should accept, including prefix variants, is already an open question on #161, and we would like to settle it once rather than widen the function case by case. Closing this one; feel free to add your case to that discussion.