Phase 1: Quick Fixes and Improvements

[dshkol]

Summary

This PR implements Phase 1 improvements focusing on documentation fixes, code quality enhancements, and minor optimizations.

Changes

Documentation

• ✅ Fixed gh_encode.Rd precision limit (was incorrectly stated as 28, corrected to 25)

Code Quality

• ✅ Added bounds checking to gh_delta to validate precision is between 0 and 25

  • Prevents silent incorrect results for invalid inputs
  • Added comprehensive tests for edge cases

• ✅ Updated CRS specification from deprecated PROJ.4 string to EPSG:4326

  • Better compatibility with modern PROJ versions
  • Updated all tests to use new format

Performance

• ✅ Optimized duplicate detection in gh_to_sp, gh_to_spdf.default, and gh_to_spdf.data.frame
  • Changed from double-scan (anyDuplicated + duplicated) to single-pass
  • Improves performance ~2x when duplicates are present
  • No change in behavior or API

Testing

• ✅ Updated tests for testthat edition 3 compatibility
• ✅ All 125 tests passing, 0 failures, 0 warnings
• ✅ No breaking changes

Testing

devtools::test()
# [ FAIL 0 | WARN 0 | SKIP 0 | PASS 125 ]

Next Steps

This is part of a series of performance improvement PRs. Upcoming phases:

• Phase 2: gh_covering grid generation optimization (6-25× speedup expected)
• Phase 3: CI/CD modernization (GitHub Actions)

🤖 Generated with Claude Code