Performs various substitutions in all .R, .Rmd and/or .Rnw files in a directory (by default only .R files are styled - see filetype argument). Carefully examine the results after running this function!

style_dir(
  path = ".",
  ...,
  style = tidyverse_style,
  transformers = style(...),
  filetype = c("R", "Rprofile"),
  recursive = TRUE,
  exclude_files = NULL,
  exclude_dirs = c("packrat", "renv"),
  include_roxygen_examples = TRUE,
  base_indention = 0,
  dry = "off"
)

Arguments

path

Path to a directory with files to transform.

...

Arguments passed on to the style function.

style

A function that creates a style guide to use, by default tidyverse_style() (without the parentheses). Not used further except to construct the argument transformers. See style_guides() for details.

transformers

A set of transformer functions. This argument is most conveniently constructed via the style argument and .... See 'Examples'.

filetype

Vector of file extensions indicating which file types should be styled. Case is ignored, and the . is optional, e.g. c(".R", ".Rmd"), or c("r", "rmd"). Supported values (after standardization) are: "r", "rprofile", "rmd", "rnw".

recursive

A logical value indicating whether or not files in subdirectories of path should be styled as well.

exclude_files

Character vector with paths to files that should be excluded from styling.

exclude_dirs

Character vector with directories to exclude.

include_roxygen_examples

Whether or not to style code in roxygen examples.

base_indention

Integer scalar indicating by how many spaces the whole output text should be indented. Note that this is not the same as splitting by line and add a base_indention spaces before the code in the case multi-line strings are present. See 'Examples'.

dry

To indicate whether styler should run in dry mode, i.e. refrain from writing back to files ."on" and "fail" both don't write back, the latter returns an error if the input code is not identical to the result of styling. "off", the default, writes back if the input and output of styling are not identical.

Value

Invisibly returns a data frame that indicates for each file considered for styling whether or not it was actually changed (or would be changed when dry is not "off").

Warning

This function overwrites files (if styling results in a change of the code to be formatted and dry = "off"). It is strongly suggested to only style files that are under version control or to create a backup copy.

We suggest to first style with scope < "tokens" and inspect and commit changes, because these changes are guaranteed to leave the abstract syntax tree (AST) unchanged. See section 'Round trip validation' for details.

Then, we suggest to style with scope = "tokens" (if desired) and carefully inspect the changes to make sure the AST is not changed in an unexpected way that invalidates code.

Round trip validation

The following section describes when and how styling is guaranteed to yield correct code.

If the style guide has scope < "tokens", no tokens are changed and the abstract syntax tree (AST) should not change. Hence, it is possible to validate the styling by comparing whether the parsed expression before and after styling have the same AST. This comparison omits comments. styler compares error if the AST has changed through styling.

Note that with scope = "tokens" such a comparison is not conducted because the AST might well change and such a change is intended. There is no way styler can validate styling, that is why we inform the user to carefully inspect the changes.

See section 'Warning' for a good strategy to apply styling safely.

See also

Examples

if (FALSE) { style_dir(file_type = "r") }