[hippi345]

Fix decoder state restoration after decoding child

Type of change

• Bug fix
• xcprojformatter (CLI) change
• Documentation update
• Test addition
• Other (describe below)

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Summary

Fixes a bug in XCJSON.Decoder.decode(_:pathComponent:) where the decoder incorrectly saved the incoming value parameter instead of its own currentValue before decoding a child element. This caused the decoder to lose track of the parent context after child decoding completed.

Related issue

Fixes #3

Changes

• Changed Decoder.swift line 33 from let oldCurrentValue = value to let oldCurrentValue = currentValue
• Added DecoderStateTests.swift with a regression test that verifies the decoder properly restores parent state after decoding a child

Testing

• Existing tests pass (swift test)
• New tests added for new functionality
• Tested manually:
  1. Added the reproducer test from issue [Bug]: Decoder does not restore the parent value after decoding a child #3 to Sources/Tests/DecoderStateTests.swift
  2. Ran swift test --filter restoresParentValueAfterDecodingChild before the fix - it failed with "Expected an instance of dictionary but an instance string was specified"
  3. Applied the one-line fix to Decoder.swift
  4. Ran the test again - it passed
  5. Ran full test suite (swift test) - all 32 tests passed

Checklist

• I have read CONTRIBUTING.md
• My change is in scope (see CONTRIBUTING.md)
• Code follows the project's style guidelines
• I have reviewed my own code and can explain all changes in detail
• Documentation updated where applicable

Additional notes

This contribution was prepared with AI assistance (Claude via Cursor Cloud Agent). The fix itself is a single-line change that corrects the variable being captured in the defer block. The test case was provided in the original issue report and validates that after decoding a child value, the decoder's currentNodeType remains .object and the parent's keyed container can be reopened.