lintr

lintr documentation

Visit Official Web Site
See How to configure lintr rules
- If custom .lintr config file is not found, .lintr will be used
See Index of problems detected by lintr

Configuration in MegaLinter

Enable lintr by adding R_LINTR in ENABLE_LINTERS variable
Disable lintr by adding R_LINTR in DISABLE_LINTERS variable

Variable	Description	Default value
R_LINTR_ARGUMENTS	User custom arguments to add in linter CLI call Ex: `-s --foo "bar"`
R_LINTR_FILTER_REGEX_INCLUDE	Custom regex including filter Ex: `(src\\|lib)`	Include every file
R_LINTR_FILTER_REGEX_EXCLUDE	Custom regex excluding filter Ex: `(test\\|examples)`	Exclude no file
R_LINTR_CLI_LINT_MODE	Override default CLI lint mode - `file`: Calls the linter for each file - `list_of_files`: Call the linter with the list of files as argument - `project`: Call the linter from the root of the project	`file`
R_LINTR_FILE_EXTENSIONS	Allowed file extensions. `"*"` matches any extension, `""` matches empty extension. Empty list excludes all files Ex: `[".py", ""]`	`[".r", ".R", ".Rmd", ".RMD"]`
R_LINTR_FILE_NAMES_REGEX	File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: `["Dockerfile(-.+)?", "Jenkinsfile"]`	Include every file
R_LINTR_PRE_COMMANDS	List of bash commands to run before the linter	None
R_LINTR_POST_COMMANDS	List of bash commands to run after the linter	None
R_LINTR_CONFIG_FILE	lintr configuration file name Use `LINTER_DEFAULT` to let the linter find it	`.lintr`
R_LINTR_RULES_PATH	Path where to find linter configuration file	Workspace folder, then MegaLinter default rules
R_LINTR_DISABLE_ERRORS	Run linter but consider errors as warnings	`false`
R_LINTR_DISABLE_ERRORS_IF_LESS_THAN	Maximum number of errors allowed	`0`

IDE Integration

Use lintr in your favorite IDE to catch errors before MegaLinter !

IDE	Extension Name	Install
Atom	Atom lintr	Visit Web Site
Emacs	flycheck	Visit Web Site
rstudio	Native Support	Visit Web Site
Sublime Text	SublimeLinter-contrib-lintr	Visit Web Site
vim	ale	Visit Web Site
Visual Studio Code	VsCode R LSP

MegaLinter Flavours

This linter is available in the following flavours

	Flavor	Description	Embedded linters	Info
	all	Default MegaLinter Flavor	97

Behind the scenes

How are identified applicable files

File extensions: .r, .R, .Rmd, .RMD

How the linting is performed

lintr is called one time by identified file

Example calls

R --slave -e "errors <- lintr::lint('myfile.r'); print(errors); quit(save = 'no', status = if (length(errors) > 0) 1 else 0) "

Help content

No documentation for ‘lintr’ in specified packages and libraries:
you could try ‘??lintr’

Installation on mega-linter Docker image

Dockerfile commands :

FROM ghcr.io/assignuser/lintr-lib:0.2.0 as lintr-lib
COPY --from=lintr-lib /usr/lib/R/library/ /home/r-library
RUN R -e "install.packages(list.dirs('/home/r-library',recursive = FALSE), repos = NULL, type = 'source')"

APK packages (Linux):
- R
- R-dev
- R-doc

Example success log

Results of lintr linter (version 2.0.1.9000)
See documentation on https://megalinter.github.io/descriptors/r_lintr/
-----------------------------------------------

[SUCCESS] .automation/test/r/r_good_1.r
    Warning message:
    In readLines(filename) :
      incomplete final line found on '.automation/test/r/r_good_1.r'

Example error log

Results of lintr linter (version 2.0.1.9000)
See documentation on https://megalinter.github.io/descriptors/r_lintr/
-----------------------------------------------

[ERROR] .automation/test/r/r_bad_1.r
    style:.automation/test/r/r_bad_1.r:8:3::Use <-, not =, for assignment.
    style:.automation/test/r/r_bad_1.r:8:14::Remove spaces before the left parenthesis in a function call.
    style:.automation/test/r/r_bad_1.r:8:17::Commas should always have a space after.
    style:.automation/test/r/r_bad_1.r:8:22::There should be a space between right parenthesis and an opening curly brace.
    style:.automation/test/r/r_bad_1.r:8:23::Opening curly braces should never go on their own line and should always be followed by a new line.
    style:.automation/test/r/r_bad_1.r:8:24::Closing curly-braces should always be on their own line, unless it's followed by an else.
    style:.automation/test/r/r_bad_1.r:11:3::Commented code should be removed.
    style:.automation/test/r/r_bad_1.r:21:1::functions should have cyclomatic complexity of less than 15, this has 22.
    style:.automation/test/r/r_bad_1.r:21:1::Variable and function names should not be longer than 30 characters.
    style:.automation/test/r/r_bad_1.r:21:1::Variable and function name style should be snake_case.
    style:.automation/test/r/r_bad_1.r:22:1::Opening curly braces should never go on their own line and should always be followed by a new line.
    style:.automation/test/r/r_bad_1.r:24:1::Lines should not be more than 80 characters.
    style:.automation/test/r/r_bad_1.r:24:44::Put spaces around all infix operators.
    warning:.automation/test/r/r_bad_1.r:24:57::Use is.na rather than == NA.
    style:.automation/test/r/r_bad_1.r:24:64::Opening curly braces should never go on their own line and should always be followed by a new line.
    style:.automation/test/r/r_bad_1.r:24:69::Closing curly-braces should always be on their own line, unless it's followed by an else.
    style:.automation/test/r/r_bad_1.r:24:76::Opening curly braces should never go on their own line and should always be followed by a new line.
    style:.automation/test/r/r_bad_1.r:24:82::Closing curly-braces should always be on their own line, unless it's followed by an else.
    style:.automation/test/r/r_bad_1.r:31:3::Do not place spaces around code in parentheses or square brackets.
    warning:.automation/test/r/r_bad_1.r:32:1::Avoid 1:length(...) expressions, use seq_len.
    style:.automation/test/r/r_bad_1.r:32:37::Put spaces around all infix operators.
    style:.automation/test/r/r_bad_1.r:32:43::`%>%` should always have a space before it and a new line after it, unless the full pipeline fits on one line.
    style:.automation/test/r/r_bad_1.r:36:9::Only use double-quotes.
    style:.automation/test/r/r_bad_1.r:40:8::Put spaces around all infix operators.
    style:.automation/test/r/r_bad_1.r:40:9::Place a space before left parenthesis, except in a function call.
    style:.automation/test/r/r_bad_1.r:43:1::Trailing blank lines are superfluous.