NEWS.md

lintr (development version)

• Added a secondary, more restrictive lint workflow - lint-changed-files - for newly written / modified code (#641, @dragosmg)
• Switched CI from Travis to GitHub Actions, using the full tidyverse recommended R CMD check. Code coverage and linting are implemented using separate GitHub Actions workflows (#572, @dragosmg)
• save_cache will now recursively create the cache directory; this avoids errors that could arise if any parent directories do not exist (#60, @dankessler).
• extract_r_source handles Rmd containing unevaluated code blocks with named format specifiers (#472, @russHyde)
• New style SNAKE_CASE for object_name_linter() (#494, @AshesITR)
• RStudio source markers are cleared when there are no lints (#520, @AshesITR)
• New assignment_spaces() lintr. (#538, @f-ritter)
• seq_linter()'s lint message is clearer about the reason for linting. (#522, @michaelchirico)
• New missing_package_linter() (#536, #547, @renkun-ken)
• New namespace_linter() (#548, #551, @renkun-ken)
• Fix possible error on invalid XML produced by xmlparsedata (#559, #560, @renkun-ken)
• Fix handling zero-length variable name error (#566, #567, @renkun-ken)
• New missing_argument_linter() (#563, #565, @renkun-ken)
• New sprintf_linter() (#544, #578, #624, #625, @renkun-ken, @AshesITR)
• Exclusions specified in the .lintr file are now relative to the location of that file and support excluding entire directories (#158, #438, @AshesITR)
• lint_dir() excludes the renv and packrat directories by default (#697, @AshesITR)
• object_name_linter() now excludes special R hook functions such as .onLoad (#500, #614, @AshesITR and @michaelchirico)
• equals_na_linter() now lints x != NA and NA == x, and skips usages in comments (#545, @michaelchirico)
• Malformed Rmd files now cause a lint instead of an error (#571, #575, @AshesITR)
• object_name_linter() gains a new default style, "symbols", which won't lint all-symbol object names (in particular, that means operator names like %+% are skipped; #495, #615, #670, @michaelchirico and @AshesITR)
• spaces_inside_linter ignores spaces preceding trailing comments (#636, @michaelchirico)
• T_and_F_symbol_linter and semicolon_terminator_linter are now part of the default linters (#517, #612, #683, #684, @AshesITR)
• with_defaults() no longer duplicates the lintr_function class when it is already present (#511, #612, @AshesITR)
• New backport_linter() for detecting mismatched R version dependencies (#506, @MichaelChirico)
• paren_brace_linter and no_tab_linter also use more reliable matching (e.g., excluding matches found in comments; #441 and #545, @russHyde)
• paren_brace_linter now marks lints at the opening brace instead of the closing parenthesis, making fixing the lints by jumping to source markers easier (#583, @AshesITR)
• Lints are now marked with the name of the linter that caused them instead of the name of their implementation function.
  Deprecated the obsolete linter argument of Lint(). (#664, #673, #746, @AshesITR)
• New syntax to exclude only selected linters from linting lines or passages. Use # nolint: linter_name, linter2_name. or # nolint start: linter_name, linter2_name. in source files or named lists of line numbers in .lintr. (#660, @AshesITR)
• Fixed spaces_left_parentheses_linter sporadically causing warnings (#654, #674, @AshesITR)
• Fixed line_length_linter causing duplicate lints for lines containing multiple expressions (#681, #682, @AshesITR)
• line_length_linter now places the source marker at the margin of the affected line to improve user experience during de-linting -- just press Return (#735, @AshesITR)
• unneeded_concatenation_linter now correctly considers arguments piped in via magrittr %>% (#573, #585, @michaelquinn32)
• Set the default complexity_limit in cyclocomp_linter to 15. This is the same complexity limit that is enforced via default_linters (#693, #695, @AshesITR).
• lint_package() now lints files in the demo directory by default (#703, @dmurdoch).
• object_usage_linter() now correctly detects global variables if there are top-level dollar-assignments (#666, #709, @AshesITR)
• commented_code_linter() uses the parse tree to find comments, eliminating some false positives (#451, @AshesITR)
• trailing_blank_lines_linter() now also lints files without a terminal newline (#675, @AshesITR)
• object_name_linter() now correctly detects imported functions when linting packages (#642, @AshesITR)
• Consistent access to linters through a function call, even for linters without parameters (#245, @fangly, @AshesITR, and @MichaelChirico)
• object_usage_linter() now correctly reports usage warnings spanning multiple lines (#507, @AshesITR)
• T_and_F_symbol_linter() no longer lints occurrences of T and F when used for subsetting and gives a better message when used as variable names (#657, @AshesITR)
• with_defaults() handles automatic naming of very long arguments correctly (#774, @michaelchirico)
• object_name_linter() no longer lints names used for subsetting (#582, @AshesITR)
• lint_package() warns and returns NULL if no package is found (instead of giving a peculiar error message) (#776, @michaelchirico)
• lint_package() is also stricter about what it considers to be a package -- folders named DESCRIPTION are ignored (#702, @michaelchirico)

lintr 2.0.1

New features

• lintr now supports GitHub Actions and will print the lints as warning messages if lints are printed during an action.
• lint_package() will now lint vignettes and data-raw by default (#447, @AshesITR).
• lint_dir() will now include Rmd and Rnw files by default (@AshesITR).

Minor fixes and features

• single_quote_linter() no longer causes a print issue when open quote appears at a column > than close quote (#457, @jamieRowen)
• absolute_path_linter() and nonportable_path_linter() now handle file-paths that are wrapped with double-quotes (#433, #437, @russHyde).
• get_source_expressions() has been changed to handle expr_or_assign_or_help tokens arising when parsing code containing equals-assignments in R-devel (#403, #456, @russHyde).
• object_usage_linter has been changed to ensure lint-position is indicated relative to the start of the file, rather than the start of a defining function (#432, @russHyde).
• commas_linter now allows spaces to come before a comma when used to denote a fall-through in a switch statement (#499, @MrMallIronmaker)

lintr 2.0.0

lintr 2.0.0 is a major release, and incorporates development changes since the last major release (1.0.0) in 2016-04-16.

Deprecated functions

• Deprecated camel_case_linter(), snake_case_linter() and multiple_dots_linter() in favor of object_name_linter() which enforce the given style: snake_case, dotted.case, lowerCamelCalse, UpperCamelCase, alllowercase or ALLUPPERCASE (#59, @fangly).
• Deprecated absolute_paths_linter() in favor of the new absolute_path_linter(), with a lax mode for fewer false positive lints (#199, fangly).

New linters

• New cyclocomp_linter() identifies overly complex functions (#361, @fabian-s)
• New equals_na_linter() (#143, #326, @jabranham)
• New extraction_operator_linter() checks that the [[ operator is used when extracting a single element from an object, not [ (subsetting) nor $ (interactive use) (@fangly).
• New function_left_parentheses_linter() to check that there is no space between a function name and its left parentheses (#204, @jrnold).
• New implicit_integer_linter() detects round numbers not declared as integers, i.e. 1 instead of 1L (@fangly).
• New nonportable_path_linter() identifies paths constructed without file.path() (@fangly).
• New paren_brace_linter() checks that there is a space between right parenthesis and an opening curly brace (@bfgray3, #242).
• New pipe_continuation_linter() to ensure there is a space before %>% and newline afterwards (#216).
• New semicolon_terminator_linter() reports semicolons at the end a line (#147, @gaborcsardi) and between expressions (#181, @fangly).
• New seq_linter(), finds 1:length(...) (and similar) expressions (#155, @gaborcsardi)
• New todo_comment_linter() lints TODOs (@fangly).
• New T_and_F_symbol_linter() warns when using T and F instead of TRUE and FALSE (@fangly).
• New undesirable_operator_linter() and undesirable_function_linter() lint uses of user-specified functions and operators (#48, #149, @fangly).
• New unneeded_concatenation_linter() lints uses of c() with a constant or no arguments (@fangly).

New functions for writing linters

• Export expect_lint() (#178, #210)
• Export ids_with_token() and with_id() (#297 @stufield)
• linters can use the XML parse tree as well now, via the https://github.com/MangoTheCat/xmlparsedata package (#154, @gaborcsardi)

New functions for users

• New lint_dir() function to lint files under a given directory (@arekbee, #360)
• New summary.lints() function to summarize the linter results (#260, #262, @wlandau).
• New checkstyle_output() function to output lints to checkstyle XML output (#156, @joshkgold)

Linter fixes

• closed_curly_linter() now allows closing parenthesis or comma after closing curly brace (#167, @Enchufa2)
• commas_linter() now handles missing arguments calls properly (#145)
• commented_code_linter() now relaxed, it no longer lints comments within roxygen blocks and does not consider "-" an R operator to avoid too many false positives.
• function_left_parentheses_linter() now allows spaces if a function starts with a left parenthesis (#311)
• no_tab_linter() now reports proper line in all cases (#134, @fangly)
• object_length_linter() argument length now defaults to 30 for consistency (#325 @DragosMG)
• object_name_linter() now works when passed multiple styles (#341, @infotroph)
• object_usage_linter() has been changed to better detect lexical scoping of global variables (#27, #336, #91, #382)
• object_usage_linter() now respects utils::globalVariables(), so it can be used to avoid false positive warnings due to non-standard evaluation (#352)
• object_usage_linter() now ignores top level calls that contain function definitions (#26).
• object_linter*()s now only lint objects declared in the current file (#76, #108, #136, #191, #194, #201, @fangly).
• open_curly_linter() and closed_curly_linter() now do not lint double curly syntax (#388)
• open_curly_linter() now allows comments after the curly braces (#188)
• pipe_continuation_linter() now behaves better in nested expressions, functions etc. (#366 @russHyde)
• space_inside_linter() now reports proper line and column numbers (#203, @fangly)

General improvements and fixes

• expect_lint() now no longer shows Rstudio markers and error messages are correctly preserved (#180, #211, @fangly)
• Lint() / as.data.frame() error now fixed (#179, @fangly).
• lint() no longer errors with inline \\Sexpr (#127).
• lint() no longer errors with '<% %>' constructs (#185).
• lint_package() now works with the cache, as intended (#146, @schloerke)
• lint_package() now excludes R/RcppExports.R by default (#282)
• lint_package() now removes fully excluded files as soon as possible to
• lintr now looks up its configuration in any parent directories as well as the package directory (#238, #345)
• seq_linter is now one of the default linters (#316).
• Fix issue in lintr's compatibility with R-devel, due to to a new version of the PCRE library (#411.)
• read_settings() now has a better error message when the config file does not end with a newline (#160, #189)
• expect_lint_free() is now automatically skipped when run on covr (#287)
• Now lintr only tries to generate comments if running in wercker or travis CI (#166)
• Add support for overriding GitHub API Token via GITHUB_TOKEN environment variable (#63, @mattyb)
• Config files are now also searched for in the users' home directory (#266, @randy3k)
• Fixed crash caused by ambiguous cache file paths (#212, @fangly).
• RStudio addins to lint current source and project (fixes #264, @JhossePaul)
• Added proper handling of tab characters (fixes #44, @fangly)
• lintr does not need the igraph package any more (#152, @gaborcsardi)
• Fixed cache not saved in a directory other than requested (#213, @fangly) avoid reading and pre-processing of ignored files (@mwaldstein)
• Allow for any number of # to start a comment. Useful in ESS (#299, @prosoitos)
• R Markdown files that do not contain chunks are no longer treated as code (#370).
• Fixed plain-code-block bug in Rmarkdown (#252, @russHyde)
• Fixed bug where non-R chunks using {lang} engine format were parsed from R-markdown (#322, @russHyde)
• Ensured lintr runs / installs / tests on R-3.6: pinned to github xmlparsedata; ensure vectors are length-1 when compared using && and || (#363 #377 #384 #391, @russHyde).

lintr 1.0.3

• Fix tests to work with changes in the parser in R 3.6

lintr 1.0.2

• Fix tests to work with upcoming testthat release.

lintr 1.0.1

• bugfix to work with knitr 1.16.7
• expect_lint_free() now is always skipped on CRAN. This is necessary because the non-binary R source may not be available when running tests on CRAN, and those tests may not be run in the package directory.

lintr 1.0.0

• bugfix to work with testthat 1.0.0

lintr 0.3.3

• infix_spaces_linter now properly checks = in named arguments. (#130, @saurfang).
• commas_linter now properly recognizes lints when preceded by a blank line and points to the missing space rather than the comma (#111, #129, @saurfang).
• Make spaces_left_parentheses_linter more robust when determining ( type (#128, @saurfang)
• commented_code_linter (#83, @jackwasey)
• Now trims long comments (#55, reported by @paulstaab)
• Automatic commenting of Github commits and pull requests when linting on Travis-CI
• expect_lint_free expectation can be added to testthat unit tests.
• Robust configuration system and exclusion logic
• Emacs and Sublime Text 3 plugins now available from their respective package repositories.
• add names.lints, split.lints (#49, @ttriche)
• Fixed bug that caused vim syntatic plugin not to work properly in windows (#46, @abossenbroek)
• allow lintr customization per project using .lintr config files.
• use globalenv() instead of baseenv() for default parent environment so that methods will be included.
• do not check object usage if eval fails. Fixes (#24, reported by @fabian-s)
• trailing_whitespace_linter was reporting the incorrect line number
• Use RStudio source marker API to display lints (#37, @jjallaire)
• Permit single quotes if they quote literal double quotes (#28, @jackwasey)

• nolint comments are respected with caching (#68, @krlmlr)

• Properly handle all knitr document formats
• Allow for (( when linting (#259, @nathaneastwood)
• Remove ^ from infix spaces to conform with tidyverse. (#302, @nathaneastwood)

lintr 0.2.0

• Initial release