Fix TypeError crash in SEP-7 replace parameter parsing

[CassioMG]

Summary

• Fix unhandled TypeError in sep7ReplacementsFromString when the replace parameter string is missing the ; hints delimiter
• Add spec-compliant validation that rejects replace values with unbalanced reference identifiers
• Add test coverage for invalid replacement strings and edge cases

Problem

sep7ReplacementsFromString calls .split() on hintsString without checking if it exists. When a replace parameter value lacks the ; delimiter (e.g. sourceAccount:X instead of sourceAccount:X;X:some hint), the destructuring on line 165 leaves hintsString as undefined, and the immediate .split() call on line 166 throws:

TypeError: Cannot read properties of undefined (reading 'split')

Fix

Per the SEP-7 spec:

The replace value is considered invalid unless the reference_identifiers are balanced on both sides of the separating semicolon.

The fix:

1. Guards against undefined on hintsString to prevent the TypeError
2. Validates that reference identifiers are balanced between the txrep side and the hints side
3. Throws Sep7InvalidUriError with a descriptive message when identifiers are unbalanced, instead of silently accepting invalid input

Tests added

• Missing hints section (no ; delimiter) — single and multiple fields — throws Sep7InvalidUriError
• Unbalanced identifiers (spec example: sourceAccount:X;Y:The account) — throws Sep7InvalidUriError
• undefined and empty string input — returns []
• End-to-end: Sep7Tx.getReplacements() with a URI whose replace param has no hints — throws Sep7InvalidUriError
• Existing tests for valid replacement strings continue to pass

[Copilot]

Pull request overview

This pull request fixes a TypeError crash in the SEP-7 replacement parameter parsing when the hints delimiter (;) is missing from the replace parameter string. The crash occurred because the code attempted to call .split() on an undefined value when no hints section was present in the replacement string format.

Changes:

• Added a guard clause to check for hintsString existence before calling .split() to prevent the TypeError crash
• Added comprehensive test coverage for replacements without hints (multiple fields, single field, undefined/empty input)
• Added end-to-end test verifying Sep7Tx.getReplacements() handles URIs with missing hints section

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
@stellar/typescript-wallet-sdk/src/walletSdk/Uri/sep7Parser.ts	Added conditional check for hintsString before processing hints to prevent TypeError when the semicolon delimiter is missing
@stellar/typescript-wallet-sdk/test/sep7.test.ts	Added 4 new test cases covering replacements without hints, including edge cases and end-to-end validation

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

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[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

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