nested_pipe_linter: Block usage of pipes nested inside other calls

In r-lib/lintr: A 'Linter' for R Code

Block usage of pipes nested inside other calls

Description

Nesting pipes harms readability; extract sub-steps to separate variables, append further pipeline steps, or otherwise refactor such usage away.

Usage

nested_pipe_linter(
  allow_inline = TRUE,
  allow_outer_calls = c("try", "tryCatch", "withCallingHandlers")
)

Arguments

allow_inline	Logical, default TRUE, in which case only "inner" pipelines which span more than one line are linted. If FALSE, even "inner" pipelines that fit in one line are linted.
allow_outer_calls	Character vector dictating which "outer" calls to exempt from the requirement to unnest (see examples). Defaults to try(), tryCatch(), and withCallingHandlers().

Tags

configurable, consistency, readability

See Also

linters for a complete list of linters available in lintr.

Examples

# will produce lints
code <- "df1 %>%\n  inner_join(df2 %>%\n    select(a, b)\n  )"
writeLines(code)
lint(
  text = code,
  linters = nested_pipe_linter()
)

lint(
  text = "df1 %>% inner_join(df2 %>% select(a, b))",
  linters = nested_pipe_linter(allow_inline = FALSE)
)

lint(
  text = "tryCatch(x %>% filter(grp == 'a'), error = identity)",
  linters = nested_pipe_linter(allow_outer_calls = character())
)

# okay
lint(
  text = "df1 %>% inner_join(df2 %>% select(a, b))",
  linters = nested_pipe_linter()
)

code <- "df1 %>%\n  inner_join(df2 %>%\n    select(a, b)\n  )"
writeLines(code)
lint(
  text = code,
  linters = nested_pipe_linter(allow_outer_calls = "inner_join")
)

lint(
  text = "tryCatch(x %>% filter(grp == 'a'), error = identity)",
  linters = nested_pipe_linter()
)

r-lib/lintr documentation built on Dec. 20, 2024, 7:24 p.m.