Object usage linter

Check that closures have the proper usage using codetools::checkUsage(). Note that this runs base::eval() on the code, so do not use with untrusted code.

Usage

object_usage_linter(interpret_glue = TRUE, skip_with = TRUE)

Arguments

interpret_glue

If TRUE, interpret glue::glue() calls to avoid false positives caused by local variables which are only used in a glue expression.

skip_with

A logical. If TRUE (default), code in with() expressions will be skipped. This argument will be passed to skipWith argument of codetools::checkUsage().

See also

linters for a complete list of linters available in lintr.

Linters

The following linters are tagged with 'package_development':

• backport_linter

• conjunct_test_linter

• expect_comparison_linter

• expect_identical_linter

• expect_length_linter

• expect_named_linter

• expect_not_linter

• expect_null_linter

• expect_s3_class_linter

• expect_s4_class_linter

• expect_true_false_linter

• expect_type_linter

• package_hooks_linter

• yoda_test_linter

Examples

# will produce lints
lint(
  text = "foo <- function() { x <- 1 }",
  linters = object_usage_linter()
)
#> <text>:1:21: warning: [object_usage_linter] local variable 'x' assigned but may not be used
#> foo <- function() { x <- 1 }
#>                     ^

# okay
lint(
  text = "foo <- function(x) { x <- 1 }",
  linters = object_usage_linter()
)
#> ℹ No lints found.

lint(
  text = "foo <- function() { x <- 1; return(x) }",
  linters = object_usage_linter()
)
#> ℹ No lints found.