Add unit tests for the useFormatXlm hook handling bigint inputs without precision loss

[Chucks1093]

Summary

The useFormatXlm hook accepts both number and bigint inputs, but bigint handling has no specific test coverage. Very large bigint values that exceed JavaScript's safe integer range must be formatted without precision loss or scientific notation.

Scope

• Test a bigint value within safe integer range formats identically to the equivalent number
• Test a bigint value above Number.MAX_SAFE_INTEGER formats without precision loss
• Test a bigint value of 0n returns 0.00
• Test a negative bigint (if supported) returns a negative formatted string or throws a clear error

Acceptance Criteria

• Safe-range bigint formats identically to equivalent number
• Above-safe-range bigint formatted without precision loss
• 0n returns 0.00
• Behaviour for negative bigint is defined and tested

ETA: 12 hours

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[Mayor-Isaac]

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Hello, I’ve gone through the requirements and I’m confident I can implement a proper solution that matches the acceptance criteria. Kindly assign this issue to me.

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[sudo-robi]

@sudo-robi has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi maintainer I'm a full stack developer and smart contract developer and auditor let me help you resolve this issue and I assure you it will be thoroughly done neatly as I have seen my way to solve the issue.

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[omarima-10]

@omarima-10 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi, my name is Omarima-10, and I am a fullstack and smart contract developer skilled in React, Next.js, JavaScript, TypeScript, Tailwind CSS, and Soroban. For this task, I will:

1. Register a single window.onunhandledrejection handler during application initialization alongside the existing window.onerror handler, ensuring it is not re-registered on component re-renders.

2. Emit a structured debug-level log for each unhandled promise rejection containing the required reason, promise_origin, and rejected_at fields, while preserving the browser's default rejection handling behaviour.

3. Ensure the handler avoids duplicate reporting for errors already captured by the React error boundary and skips logging entirely when running in the test environment.

4. Add targeted tests verifying one-time handler registration, structured log generation, test-environment exclusion, and the absence of duplicate logging or behavioural regressions.

ETA: 10 hours

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Congratulations, @omarima-10! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

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