unnecessary_placeholder_linter {lintr}

Block usage of pipeline placeholders if unnecessary

Description

The argument placeholder . in magrittr pipelines is unnecessary if passed as the first positional argument; using it can cause confusion and impacts readability.

Usage

unnecessary_placeholder_linter()

Details

This is true for forward (⁠%>%⁠), assignment (⁠%<>%⁠), and tee (⁠%T>%⁠) operators.

Tags

best_practices, readability

See Also

linters for a complete list of linters available in lintr.

Examples

# will produce lints
lint(
  text = "x %>% sum(., na.rm = TRUE)",
  linters = unnecessary_placeholder_linter()
)

# okay
lint(
  text = "x %>% sum(na.rm = TRUE)",
  linters = unnecessary_placeholder_linter()
)

lint(
  text = "x %>% lm(data = ., y ~ z)",
  linters = unnecessary_placeholder_linter()
)

lint(
  text = "x %>% outer(., .)",
  linters = unnecessary_placeholder_linter()
)