nzchar

Flag comparisons of nchar(x) against zero—nchar(x) > 0, nchar(x) >= 1, nchar(x) != 0, and their mirrored and negated spellings—which are the purpose-built nzchar(x) (or !nzchar(x) for the empty test): faster, and it states the intent directly.

The rule fires only on the clean single-argument shape and only when nchar resolves to base R; a local redefinition is left alone. The fix is unsafe: on NA_character_ input nzchar yields TRUE where the nchar comparison yields NA (exact equivalence would need nzchar(x, keepNA = TRUE)).

Testing for non-empty strings:

keep <- x[nchar(x) > 0]

warning: nzchar
 --> example.R:1:11
  |
1 | keep <- x[nchar(x) > 0]
  |           ^^^^^^^^^^^^ comparing `nchar()` to zero is the faster, clearer `nzchar()`
  = help: Use `nzchar(x)` for non-empty, `!nzchar(x)` for empty.