Brace linter

Perform various style checks related to placement and spacing of curly braces:

Usage

brace_linter(
  allow_single_line = FALSE,
  function_bodies = c("multi_line", "always", "not_inline", "never")
)

Arguments

allow_single_line

If TRUE, allow an open and closed curly pair on the same line.

function_bodies

When to require function bodies to be wrapped in curly braces. One of

• "always" to require braces around all function bodies, including inline functions,

• "not_inline" to require braces when a function body does not start on the same line as its signature,

• "multi_line" (the default) to require braces when a function definition spans multiple lines,

• "never" to never require braces in function bodies.

Details

• Opening curly braces are never on their own line and are always followed by a newline.

• Opening curly braces have a space before them.

• Closing curly braces are on their own line unless they are followed by an else.

• Closing curly braces in if conditions are on the same line as the corresponding else.

• Either both or neither branch in if/else use curly braces, i.e., either both branches use {...} or neither does.

• Function bodies are wrapped in curly braces.

See also

• linters for a complete list of linters available in lintr.

• https://style.tidyverse.org/syntax.html#indenting

• https://style.tidyverse.org/syntax.html#if-statements

Tags

configurable, default, readability, style

Examples

# will produce lints
lint(
  text = "f <- function() { 1 }",
  linters = brace_linter()
)
#> <text>:1:17: style: [brace_linter] Opening curly braces should never go on their own line and should always be followed by a new line.
#> f <- function() { 1 }
#>                 ^
#> <text>:1:21: style: [brace_linter] Closing curly-braces should always be on their own line, unless they are followed by an else.
#> f <- function() { 1 }
#>                     ^

writeLines("if (TRUE) {\n return(1) }")
#> if (TRUE) {
#>  return(1) }
lint(
  text = "if (TRUE) {\n return(1) }",
  linters = brace_linter()
)
#> <text>:2:12: style: [brace_linter] Closing curly-braces should always be on their own line, unless they are followed by an else.
#>  return(1) }
#>            ^

# okay
writeLines("f <- function() {\n  1\n}")
#> f <- function() {
#>   1
#> }
lint(
  text = "f <- function() {\n  1\n}",
  linters = brace_linter()
)
#> ℹ No lints found.

writeLines("if (TRUE) { \n return(1) \n}")
#> if (TRUE) { 
#>  return(1) 
#> }
lint(
  text = "if (TRUE) { \n return(1) \n}",
  linters = brace_linter()
)
#> ℹ No lints found.

# customizing using arguments
writeLines("if (TRUE) { return(1) }")
#> if (TRUE) { return(1) }
lint(
  text = "if (TRUE) { return(1) }",
  linters = brace_linter(allow_single_line = TRUE)
)
#> ℹ No lints found.