refactor(validation): improve error messages and validation logic

[Obiajulu-gif]

Closes #32
This pull request enhances the validation logic in the ValidationProvider class for the sweeps module, improving robustness and clarity of error handling. The changes focus on stricter checks for account status, expiration, and input formats, as well as more precise error messages. The most important changes are grouped below:

Account Status and Expiry Validation Improvements:

• Added explicit checks for additional account statuses (CLAIMED, EXPIRED), returning specific error messages when an account is already swept or expired. Now also checks if the expiresAt field is a valid date before further validation.
• Ensured all methods that check expiry (expiresAt) validate both the type and value of the date to prevent invalid date errors. [1] [2]

Input Format Validation Enhancements:

• Added a new private method isValidAmount to strictly validate the amount as a positive number with up to 7 decimal places, and replaced previous ad-hoc amount checks with this method. [1] [2]
• Improved isValidStellarAddress to check that the input is a string, matches the expected regex, and passes the StrKey.isValidEd25519PublicKey check for Stellar addresses.
• Enhanced isValidAssetFormat to ensure the asset input is a string before further validation.

These changes make the validation logic more robust, reduce the likelihood of runtime errors, and provide clearer feedback for invalid operations.

[Obiajulu-gif]

@phertyameen please review the code and remember to allocate complement points. thank you

[phertyameen]

Critical Gaps

1. Stellar Amount Limits

Missing: Tests for Stellar's actual maximum amount (922 trillion+)
Where: validateSweepParameters amount validation tests
Fix: Add tests for amounts at/near Stellar's precision limit

2. Real Concurrent Sweeps

Missing: True race condition tests with simultaneous validation calls
Where: Account state machine section
Fix: Use Promise.all() to fire multiple validations simultaneously and verify only one succeeds

3. Database Failures During Operations

Missing: Connection drops, partial data, mid-operation failures
Where: Scattered - needs dedicated section
Fix: Add "Database Interaction Failures" test suite with connection errors, timeout, concurrent deletes

4. Asset Code Coverage

Missing: 1-character codes, codes with numbers, systematic 1-12 length testing
Where: Asset format validation tests
Fix: Test all valid asset code patterns per Stellar spec (alphanumeric, 1-12 chars)

Moderate Gaps
5. Security Injection Attempts

Missing: SQL/NoSQL injection, script injection in all string fields
Where: Input sanitization section (barely exists)
Fix: Create "Input Sanitization & Injection Safety" test suite

6. Information Leakage

Missing: Timing attacks, account existence revelation through errors
Where: Error message and validation order sections
Fix: Add tests verifying errors don't leak sensitive info or timing differences

7. Amount Edge Cases

Missing: Leading zeros, amounts with 8+ decimals, near-limit values
Where: Amount validation tests
Fix: Add boundary tests around format edge cases

How to Address
Create 3 new test sections:

"Concurrent Operations & Race Conditions" - real parallelism tests
"Database Failure Modes" - connection/query failures, stale data
"Security & Attack Scenarios" - injections, timing attacks, information leakage

Enhance existing sections:

Amount tests: add Stellar limit and format edge cases
Asset tests: systematic coverage of 1-12 character codes with numbers
Expiration tests: add far future and Year 2038 scenarios

[Obiajulu-gif]

Critical Gaps

1. Stellar Amount Limits

Missing: Tests for Stellar's actual maximum amount (922 trillion+) Where: validateSweepParameters amount validation tests Fix: Add tests for amounts at/near Stellar's precision limit

2. Real Concurrent Sweeps

Missing: True race condition tests with simultaneous validation calls Where: Account state machine section Fix: Use Promise.all() to fire multiple validations simultaneously and verify only one succeeds

3. Database Failures During Operations

Missing: Connection drops, partial data, mid-operation failures Where: Scattered - needs dedicated section Fix: Add "Database Interaction Failures" test suite with connection errors, timeout, concurrent deletes

4. Asset Code Coverage

Missing: 1-character codes, codes with numbers, systematic 1-12 length testing Where: Asset format validation tests Fix: Test all valid asset code patterns per Stellar spec (alphanumeric, 1-12 chars)

Moderate Gaps 5. Security Injection Attempts

Missing: SQL/NoSQL injection, script injection in all string fields Where: Input sanitization section (barely exists) Fix: Create "Input Sanitization & Injection Safety" test suite

6. Information Leakage

Missing: Timing attacks, account existence revelation through errors Where: Error message and validation order sections Fix: Add tests verifying errors don't leak sensitive info or timing differences

7. Amount Edge Cases

Missing: Leading zeros, amounts with 8+ decimals, near-limit values Where: Amount validation tests Fix: Add boundary tests around format edge cases

How to Address Create 3 new test sections:

"Concurrent Operations & Race Conditions" - real parallelism tests "Database Failure Modes" - connection/query failures, stale data "Security & Attack Scenarios" - injections, timing attacks, information leakage

Enhance existing sections:

Amount tests: add Stellar limit and format edge cases Asset tests: systematic coverage of 1-12 character codes with numbers Expiration tests: add far future and Year 2038 scenarios

@phertyameen i have fix the issue

[Obiajulu-gif]

@phertyameen thank you so much ma'am...
Help me out with compliments for job well done ... Please 🥺