Object name linter

Check that object names conform to a naming style. The default naming styles are "snake_case" and "symbols".

Usage

object_name_linter(styles = c("snake_case", "symbols"), regexes = character())

Arguments

styles

A subset of ‘symbols’, ‘CamelCase’, ‘camelCase’, ‘snake_case’, ‘SNAKE_CASE’, ‘dotted.case’, ‘lowercase’, ‘UPPERCASE’ . A name should match at least one of these styles. The "symbols" style refers to names containing only non-alphanumeric characters; e.g., defining %+% from ggplot2 or %>% from magrittr would not generate lint markers, whereas %m+% from lubridate (containing both alphanumeric and non-alphanumeric characters) would.

regexes

A (possibly named) character vector specifying a custom naming convention. If named, the names will be used in the lint message. Otherwise, the regexes enclosed by / will be used in the lint message. Note that specifying regexes overrides the default styles. So if you want to combine regexes and styles, both need to be explicitly specified.

Details

Quotes (`"') and specials (% and trailing <-) are not considered part of the object name.

Note when used in a package, in order to ignore objects imported from other namespaces, this linter will attempt getNamespaceExports() whenever an import(PKG) or importFrom(PKG, ...) statement is found in your NAMESPACE file. If requireNamespace() fails (e.g., the package is not yet installed), the linter won't be able to ignore some usages that would otherwise be allowed.

Suppose, for example, you have import(upstream) in your NAMESPACE, which makes available its exported S3 generic function a_really_quite_long_function_name that you then extend in your package by defining a corresponding method for your class my_class. Then, if upstream is not installed when this linter runs, a lint will be thrown on this object (even though you don't "own" its full name).

The best way to get lintr to work correctly is to install the package so that it's available in the session where this linter is running.

See also

linters for a complete list of linters available in lintr.

Tags

configurable, consistency, default, executing, style

Examples

# will produce lints
lint(
  text = "my_var <- 1L",
  linters = object_name_linter(styles = "CamelCase")
)
#> <text>:1:1: style: [object_name_linter] Variable and function name style should match CamelCase.
#> my_var <- 1L
#> ^~~~~~

lint(
  text = "xYz <- 1L",
  linters = object_name_linter(styles = c("UPPERCASE", "lowercase"))
)
#> <text>:1:1: style: [object_name_linter] Variable and function name style should match UPPERCASE or lowercase.
#> xYz <- 1L
#> ^~~

lint(
  text = "MyVar <- 1L",
  linters = object_name_linter(styles = "dotted.case")
)
#> <text>:1:1: style: [object_name_linter] Variable and function name style should match dotted.case.
#> MyVar <- 1L
#> ^~~~~

lint(
  text = "asd <- 1L",
  linters = object_name_linter(regexes = c(my_style = "F$", "f$"))
)
#> <text>:1:1: style: [object_name_linter] Variable and function name style should match my_style or /f$/.
#> asd <- 1L
#> ^~~

# okay
lint(
  text = "my_var <- 1L",
  linters = object_name_linter(styles = "snake_case")
)
#> ℹ No lints found.

lint(
  text = "xyz <- 1L",
  linters = object_name_linter(styles = "lowercase")
)
#> ℹ No lints found.

lint(
  text = "my.var <- 1L; myvar <- 2L",
  linters = object_name_linter(styles = c("dotted.case", "lowercase"))
)
#> ℹ No lints found.

lint(
  text = "asdf <- 1L; asdF <- 1L",
  linters = object_name_linter(regexes = c(my_style = "F$", "f$"))
)
#> ℹ No lints found.