r6_usage_linter {box.linters}

R6 class usage linter

Description

Checks method and attribute calls within an R6 class. Covers public, private, and active objects. All internal calls should exist. All private methods and attributes should be used.

Usage

r6_usage_linter()

Details

For use in rhino, see the Explanation: Rhino style guide to learn about the details.

Value

A custom linter function for use with r-lib/lintr.

Examples

# will produce lints
code = "
box::use(
  R6[R6Class],
)

badClass <- R6Class('badClass',
  public = list(
    initialize = function() {
      private$not_exists()
    }
  ),
  private = list(
    unused_attribute = 'private data',
    unused_method = function() {
      self$attribute_not_exists
      self$function_not_exists()
    }
  )
)
"

lintr::lint(
  text = code,
  linters = r6_usage_linter()
)

# okay
code = "
box::use(
  R6[R6Class],
)

goodClass <- R6Class('goodClass',
  public = list(
    public_attr = NULL,
    initialize = function() {
      private$private_func()
    },
    some_function = function () {
      private$private_attr
    }
  ),
  private = list(
    private_attr = 'private data',
    private_func = function() {
      self$public_attr
    }
  )
)
"

lintr::lint(
  text = code,
  linters = r6_usage_linter()
)