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 Mega-Linter

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	`{linter.cli_lint_mode}`
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 Mega-Linter 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 Mega-Linter !

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

Mega-Linter Flavours

This linter is available in the following flavours

	Flavor	Description	Embedded linters	Info
	all	Default Mega-Linter Flavor	94

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.