tests: add edge-case tests for str_wrap()

[LeonidasZhak]

Summary

Adds edge-case tests for str_wrap() covering common data cleaning scenarios that had limited test coverage.

Changes

File: tests/testthat/test-wrap.R (+51 lines)

Tests Added (8 test blocks)

1. str_wrap() handles NA values — Verifies NA preservation for single NA, mixed NA/vector, and NA in middle of vector
2. str_wrap() handles empty input — Empty string and empty character vector
3. str_wrap() works with vector input — Element-wise processing of character vectors
4. str_wrap() respects indent parameter — First line indentation
5. str_wrap() respects exdent parameter — Subsequent line indentation
6. str_wrap() handles single word longer than width — Word longer than target width is not broken
7. str_wrap() collapses multiple whitespace — Leading/trailing/internal whitespace normalization
8. str_wrap() validates its inputs — Error on invalid width, indent, exdent, whitespace_only

Motivation

str_wrap() is a key text formatting function used in data cleaning pipelines (e.g., formatting labels, wrapping long strings). The existing tests (23 lines) only covered basic wrapping, whitespace-only mode, and name preservation. These additions cover common edge cases encountered when processing real-world text data.

Testing

• devtools::test(filter = "wrap"): 0 failures, 20 passes (4 existing + 16 new)
• No regressions in existing tests

[LeonidasZhak]

Withdrawing this small automated PR while I consolidate an oversized batch of contributions and reduce maintainer review burden. Sorry for the noise, and thank you for maintaining the project.