Use raw strings in some places

NEWS.md

@@ -86,6 +86,7 @@
 ## Notes
 
 * All user-facing messages are now prepared using the `{cli}` package (#2418, @IndrajeetPatil). All messages have been reviewed and updated to be more informative and consistent.
+* {lintr} now depens on R version 4.0.0. It already does so implicitly due to recursive upstream dependencies requiring this version; we've simply made that dependency explicit and up-front (#2569, @MichaelChirico).
 * {lintr} now depends on R version 4.0.0. It already does so implicitly due to recursive upstream dependencies requiring this version; we've simply made that dependency explicit and up-front (#2569, @MichaelChirico).
 
 # lintr 3.1.2

R/zzz.R

@@ -168,9 +168,9 @@ default_undesirable_functions <- all_undesirable_functions[names(all_undesirable
 
 rd_auto_link <- function(x) {
   x <- unlist(x)
-  x <- gsub("([a-zA-Z0-9.]+)::([a-zA-Z0-9._]+)\\(\\)", "\\\\code{\\\\link[\\1:\\2]{\\1::\\2()}}", x)
-  x <- gsub("([^:a-zA-Z0-9._])([a-zA-Z0-9._]+)\\(\\)", "\\1\\\\code{\\\\link[=\\2]{\\2()}}", x)
-  x <- gsub("`([^`]+)`", "\\\\code{\\1}", x)
+  x <- gsub(R"{([a-zA-Z0-9.]+)::([a-zA-Z0-9._]+)\(\)}", R"(\\code{\\link[\1:\2]{\1::\2()}})", x)
+  x <- gsub(R"{([^:a-zA-Z0-9._])([a-zA-Z0-9._]+)\(\)}", R"(\1\\code{\\link[=\2]{\2()}})", x)
+  x <- gsub("`([^`]+)`", R"(\\code{\1})", x)
   x
 }
 
@@ -181,7 +181,7 @@ rd_undesirable_functions <- function() {
     "The following functions are sometimes regarded as undesirable:",
     "\\itemize{",
     sprintf(
-      "\\item \\code{\\link[=%1$s]{%1$s()}} As an alternative, %2$s.",
+      R"(\item \code{\link[=%1$s]{%1$s()}} As an alternative, %2$s.)",
       names(default_undesirable_functions), alternatives
     ),
     "}"

tests/testthat/test-fixed_regex_linter.R

@@ -1,25 +1,19 @@
-# NB: escaping is confusing. We have to double-escape everything -- the first
-#   escape creates a string that will be parse()d, the second escape is normal
-#   escaping that would be done in R code. E.g. in "\\\\.", the R code would
-#   read like "\\.", but in order to create those two slashes, we need to write
-#   "\\\\." in the string here.
-
 test_that("fixed_regex_linter skips allowed usages", {
   linter <- fixed_regex_linter()
 
   expect_lint("gsub('^x', '', y)", NULL, linter)
   expect_lint("grep('x$', '', y)", NULL, linter)
   expect_lint("sub('[a-zA-Z]', '', y)", NULL, linter)
   expect_lint("grepl(fmt, y)", NULL, linter)
-  expect_lint("regexec('\\\\s', '', y)", NULL, linter)
+  expect_lint(R"{regexec('\\s', '', y)}", NULL, linter)
   expect_lint("grep('a(?=b)', x, perl = TRUE)", NULL, linter)
   expect_lint("grep('0+1', x, perl = TRUE)", NULL, linter)
   expect_lint("grep('1*2', x)", NULL, linter)
   expect_lint("grep('a|b', x)", NULL, linter)
-  expect_lint("grep('\\\\[|\\\\]', x)", NULL, linter)
+  expect_lint(R"{grep('\\[|\\]', x)}", NULL, linter)
 
   # if fixed=TRUE is already set, regex patterns don't matter
-  expect_lint("gsub('\\\\.', '', y, fixed = TRUE)", NULL, linter)
+  expect_lint(R"{gsub('\\.', '', y, fixed = TRUE)}", NULL, linter)
 
   # ignore.case=TRUE implies regex interpretation
   expect_lint("gsub('abcdefg', '', y, ignore.case = TRUE)", NULL, linter)
@@ -37,10 +31,10 @@ test_that("fixed_regex_linter blocks simple disallowed usages", {
   linter <- fixed_regex_linter()
   lint_msg <- rex::rex("This regular expression is static")
 
-  expect_lint("gsub('\\\\.', '', x)", lint_msg, linter)
+  expect_lint(R"{gsub('\\.', '', x)}", lint_msg, linter)
   expect_lint("grepl('abcdefg', x)", lint_msg, linter)
   expect_lint("gregexpr('a-z', y)", lint_msg, linter)
-  expect_lint("regexec('\\\\$', x)", lint_msg, linter)
+  expect_lint(R"{regexec('\\$', x)}", lint_msg, linter)
   expect_lint("grep('\n', x)", lint_msg, linter)
 
   # naming the argument doesn't matter (if it's still used positionally)
@@ -51,21 +45,21 @@ patrick::with_parameters_test_that(
   "fixed_regex_linter is robust to unrecognized escapes error",
   {
     expect_lint(
-      sprintf("grep('\\\\%s', x)", char),
+      sprintf(R"{grep('\\%s', x)}", char),
       rex::rex("This regular expression is static"),
       fixed_regex_linter()
     )
 
     expect_lint(
-      sprintf("strsplit('a%sb', '\\\\%s')", char, char),
+      sprintf(R"{strsplit('a%sb', '\\%s')}", char, char),
       rex::rex("This regular expression is static"),
       fixed_regex_linter()
     )
   },
   .cases = local({
     char <- c(
       "^", "$", "{", "}", "(", ")", ".", "*", "+", "?",
-      "|", "[", "]", "\\\\", "<", ">", "=", ":", ";", "/",
+      "|", "[", "]", R"(\\)", "<", ">", "=", ":", ";", "/",
       "_", "-", "!", "@", "#", "%", "&", "~"
     )
     data.frame(char = char, .test_name = char, stringsAsFactors = FALSE)
@@ -87,7 +81,7 @@ test_that("fixed_regex_linter catches null calls to strsplit as well", {
   linter <- fixed_regex_linter()
 
   expect_lint("strsplit(x, '^x')", NULL, linter)
-  expect_lint("strsplit(x, '\\\\s')", NULL, linter)
+  expect_lint(R"{strsplit(x, '\\s')}", NULL, linter)
   expect_lint("strsplit(x, 'a(?=b)', perl = TRUE)", NULL, linter)
   expect_lint("strsplit(x, '0+1', perl = TRUE)", NULL, linter)
   expect_lint("strsplit(x, 'a|b')", NULL, linter)
@@ -97,15 +91,15 @@ test_that("fixed_regex_linter catches null calls to strsplit as well", {
   expect_lint("tstrsplit(x, fmt)", NULL, linter)
 
   # if fixed=TRUE is already set, regex patterns don't matter
-  expect_lint("strsplit(x, '\\\\.', fixed = TRUE)", NULL, linter)
-  expect_lint("strsplit(x, '\\\\.', fixed = T)", NULL, linter)
+  expect_lint(R"{strsplit(x, '\\.', fixed = TRUE)}", NULL, linter)
+  expect_lint(R"{strsplit(x, '\\.', fixed = T)}", NULL, linter)
 })
 
 test_that("fixed_regex_linter catches calls to strsplit as well", {
   linter <- fixed_regex_linter()
   lint_msg <- rex::rex("This regular expression is static")
 
-  expect_lint("strsplit(x, '\\\\.')", lint_msg, linter)
+  expect_lint(R"{strsplit(x, '\\.')}", lint_msg, linter)
   expect_lint("strsplit(x, '[.]')", lint_msg, linter)
 
   expect_lint("tstrsplit(x, 'abcdefg')", lint_msg, linter)
@@ -115,8 +109,8 @@ test_that("fixed_regex_linter is more exact about distinguishing \\s from \\:",
   linter <- fixed_regex_linter()
   lint_msg <- rex::rex("This regular expression is static")
 
-  expect_lint("grep('\\\\s', '', x)", NULL, linter)
-  expect_lint("grep('\\\\:', '', x)", lint_msg, linter)
+  expect_lint(R"{grep('\\s', '', x)}", NULL, linter)
+  expect_lint(R"{grep('\\:', '', x)}", lint_msg, linter)
 })
 
 ## tests for stringr functions
@@ -126,12 +120,12 @@ test_that("fixed_regex_linter skips allowed stringr usages", {
   expect_lint("str_replace(y, '[a-zA-Z]', '')", NULL, linter)
   expect_lint("str_replace_all(y, '^x', '')", NULL, linter)
   expect_lint("str_detect(y, fmt)", NULL, linter)
-  expect_lint("str_extract(y, '\\\\s')", NULL, linter)
-  expect_lint("str_extract_all(y, '\\\\s')", NULL, linter)
+  expect_lint(R"{str_extract(y, '\\s')}", NULL, linter)
+  expect_lint(R"{str_extract_all(y, '\\s')}", NULL, linter)
   expect_lint("str_which(x, '1*2')", NULL, linter)
 
   # if fixed() is already set, regex patterns don't matter
-  expect_lint("str_replace(y, fixed('\\\\.'), '')", NULL, linter)
+  expect_lint(R"{str_replace(y, fixed('\\.'), '')}", NULL, linter)
 
   # namespace qualification doesn't matter
   expect_lint("stringr::str_replace(y, stringr::fixed('abcdefg'), '')", NULL, linter)
@@ -141,16 +135,16 @@ test_that("fixed_regex_linter blocks simple disallowed usages of stringr functio
   linter <- fixed_regex_linter()
   lint_msg <- rex::rex("This regular expression is static")
 
-  expect_lint("str_replace_all(x, '\\\\.', '')", lint_msg, linter)
+  expect_lint(R"{str_replace_all(x, '\\.', '')}", lint_msg, linter)
   expect_lint("str_detect(x, 'abcdefg')", lint_msg, linter)
   expect_lint("str_locate(y, 'a-z')", lint_msg, linter)
-  expect_lint("str_subset(x, '\\\\$')", lint_msg, linter)
+  expect_lint(R"{str_subset(x, '\\$')}", lint_msg, linter)
   expect_lint("str_which(x, '\n')", lint_msg, linter)
 
   # named, positional arguments are still caught
   expect_lint("str_locate(y, pattern = 'a-z')", lint_msg, linter)
   # nor do other named arguments throw things off
-  expect_lint("str_starts(x, '\\\\.', negate = TRUE)", lint_msg, linter)
+  expect_lint(R"{str_starts(x, '\\.', negate = TRUE)}", lint_msg, linter)
 })
 
 test_that("fixed_regex_linter catches calls to str_split as well", {
@@ -161,8 +155,8 @@ test_that("fixed_regex_linter catches calls to str_split as well", {
   expect_lint("str_split(x, fmt)", NULL, linter)
 
   # if fixed() is already set, regex patterns don't matter
-  expect_lint("str_split(x, fixed('\\\\.'))", NULL, linter)
-  expect_lint("str_split(x, '\\\\.')", lint_msg, linter)
+  expect_lint(R"{str_split(x, fixed('\\.'))}", NULL, linter)
+  expect_lint(R"{str_split(x, '\\.')}", lint_msg, linter)
   expect_lint("str_split(x, '[.]')", lint_msg, linter)
 })
 
@@ -187,24 +181,24 @@ test_that("one-character character classes with escaped characters are caught",
   linter <- fixed_regex_linter()
   lint_msg <- rex::rex("This regular expression is static")
 
-  expect_lint("gsub('[\\n]', '', x)", lint_msg, linter)
-  expect_lint("gsub('[\\\"]', '', x)", lint_msg, linter)
-  expect_lint('gsub("\\\\<", "x", x, perl = TRUE)', lint_msg, linter)
-
-  expect_lint("str_split(x, '[\\1]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\12]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\123]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\xa]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\x32]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\uF]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\u01]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\u012]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\u0123]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\U8]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\U1d4d7]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\u{1}]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\U{F7D5}]')", lint_msg, linter)
-  expect_lint("str_split(x, '[\\U{1D4D7}]')", lint_msg, linter)
+  expect_lint(R"{gsub('[\n]', '', x)}", lint_msg, linter)
+  expect_lint(R"{gsub('[\"]', '', x)}", lint_msg, linter)
+  expect_lint(R'{gsub("\\<", "x", x, perl = TRUE)}', lint_msg, linter)
+
+  expect_lint(R"{str_split(x, '[\1]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\12]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\123]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\xa]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\x32]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\uF]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\u01]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\u012]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\u0123]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\U8]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\U1d4d7]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\u{1}]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\U{F7D5}]')}", lint_msg, linter)
+  expect_lint(R"{str_split(x, '[\U{1D4D7}]')}", lint_msg, linter)
 })
 
 test_that("bracketed unicode escapes are caught", {
@@ -218,15 +212,15 @@ test_that("bracketed unicode escapes are caught", {
 
 test_that("escaped characters are handled correctly", {
   linter <- fixed_regex_linter()
-  expect_lint("gsub('\\n+', '', sql)", NULL, linter)
+  expect_lint(R"{gsub('\n+', '', sql)}", NULL, linter)
   expect_lint('gsub("\\n{2,}", "\n", D)', NULL, linter)
-  expect_lint('gsub("[\\r\\n]", "", x)', NULL, linter)
-  expect_lint('gsub("\\n $", "", y)', NULL, linter)
-  expect_lint('gsub("```\\n*```r*\\n*", "", x)', NULL, linter)
+  expect_lint(R'{gsub("[\r\n]", "", x)}', NULL, linter)
+  expect_lint(R'{gsub("\n $", "", y)}', NULL, linter)
+  expect_lint(R'{gsub("```\n*```r*\n*", "", x)}', NULL, linter)
   expect_lint('strsplit(x, "(;|\n)")', NULL, linter)
-  expect_lint('strsplit(x, "(;|\\n)")', NULL, linter)
-  expect_lint('grepl("[\\\\W]", x, perl = TRUE)', NULL, linter)
-  expect_lint('grepl("[\\\\W]", x)', NULL, linter)
+  expect_lint(R'{strsplit(x, "(;|\n)")}', NULL, linter)
+  expect_lint(R'{grepl("[\\W]", x, perl = TRUE)}', NULL, linter)
+  expect_lint(R'{grepl("[\\W]", x)}', NULL, linter)
 })
 
 # make sure the logic is properly vectorized
@@ -238,10 +232,10 @@ test_that("fixed replacements vectorize and recognize str_detect", {
   linter <- fixed_regex_linter()
   # properly vectorized
   expect_lint(
-    trim_some("{
+    trim_some(R"({
       grepl('abcdefg', x)
-      grepl('a[.]\\\\.b\\n', x)
-    }"),
+      grepl('a[.]\\.b\n', x)
+    })"),
     list(
       list(rex::rex('Use "abcdefg" with fixed = TRUE'), line_number = 2L),
       list(rex::rex('Use "a..b\\n" with fixed = TRUE'), line_number = 3L)
@@ -289,37 +283,37 @@ robust_non_printable_unicode <- function() {
 # styler: off
 local({
   .cases <- tibble::tribble(
-    ~.test_name,            ~regex_expr,            ~fixed_expr,
-    "[.]",                  "[.]",                  ".",
-    '[\\\"]',               '[\\\"]',               '\\"',
-    "[]]",                  "[]]",                  "]",
-    "\\\\.",                "\\\\.",                ".",
-    "\\\\:",                "\\\\:",                ":",
-    "\\\\<",                "\\\\<",                "<",
-    "\\\\$",                "\\\\$",                "$",
-    "[\\1]",                "[\\1]",                "\\001",
-    "\\1",                  "\\1",                  "\\001",
-    "[\\12]",               "[\\12]",               "\\n",
-    "[\\123]",              "[\\123]",              "S",
-    "a[*]b",                "a[*]b",                "a*b",
-    "abcdefg",              "abcdefg",              "abcdefg",
-    "abc\\U{A0DEF}ghi",     "abc\\U{A0DEF}ghi",     robust_non_printable_unicode(),
-    "a-z",                  "a-z",                  "a-z",
-    "[\\n]",                "[\\n]",                "\\n",
-    "\\n",                  "\n",                   "\\n",
-    "[\\u01]",              "[\\u01]",              "\\001",
-    "[\\u012]",             "[\\u012]",             "\\022",
-    "[\\u0123]",            "[\\u0123]",            "\u0123",
-    "[\\u{1}]",             "[\\u{1}]",             "\\001",
-    "[\\U1d4d7]",           "[\\U1d4d7]",           "\U1D4D7",
-    "[\\U{1D4D7}]",         "[\\U{1D4D7}]",         "\U1D4D7",
-    "[\\U8]",               "[\\U8]",               "\\b",
-    "\\u{A0}",              "\\u{A0}",              "\uA0",
-    "\\u{A0}\\U{0001d4d7}", "\\u{A0}\\U{0001d4d7}", "\uA0\U1D4D7",
-    "[\\uF]",               "[\\uF]",               "\\017",
-    "[\\U{F7D5}]",          "[\\U{F7D5}]",          "\UF7D5",
-    "[\\x32]",              "[\\x32]",              "2",
-    "[\\xa]",               "[\\xa]",               "\\n"
+    ~.test_name,             ~regex_expr,             ~fixed_expr,
+    "[.]",                   "[.]",                   ".",
+    '[\\\"]',                R'([\"])',               '\\"',
+    "[]]",                   "[]]",                   "]",
+    R"(\\.)",                R"(\\.)",                ".",
+    R"(\\:)",                R"(\\:)",                ":",
+    R"(\\<)",                R"(\\<)",                "<",
+    R"(\\$)",                R"(\\$)",                "$",
+    R"([\1])",               R"([\1])",               R"(\001)",
+    R"(\1)",                 R"(\1)",                 R"(\001)",
+    R"([\12])",              R"([\12])",              R"(\n)",
+    R"([\123])",             R"([\123])",             "S",
+    "a[*]b",                 "a[*]b",                 "a*b",
+    "abcdefg",               "abcdefg",               "abcdefg",
+    "abc\\U{A0DEF}ghi",      "abc\\U{A0DEF}ghi",      robust_non_printable_unicode(),
+    "a-z",                   "a-z",                   "a-z",
+    R"([\n])",               R"([\n])",               R"(\n)",
+    R"(\n)",                 "\n",                    R"(\n)",
+    R"([\u01])",             R"([\u01])",             R"(\001)",
+    R"([\u012])",            R"([\u012])",            R"(\022)",
+    R"([\u0123])",           R"([\u0123])",           "\u0123",
+    R"([\u{1}])",            R"([\u{1}])",            R"(\001)",
+    R"([\U1d4d7])",          R"([\U1d4d7])",          "\U1D4D7",
+    R"([\U{1D4D7}])",        R"([\U{1D4D7}])",        "\U1D4D7",
+    R"([\U8])",              R"([\U8])",              R"(\b)",
+    R"(\u{A0})",             R"(\u{A0})",             "\uA0",
+    R"(\u{A0}\U{0001d4d7})", R"(\u{A0}\U{0001d4d7})", "\uA0\U1D4D7",
+    R"([\uF])",              R"([\uF])",              R"(\017)",
+    R"([\U{F7D5}])",         R"([\U{F7D5}])",         "\UF7D5",
+    R"([\x32])",             R"([\x32])",             "2",
+    R"([\xa])",              R"([\xa])",              R"(\n)"
   )
   if (.Platform$OS.type == "windows" && !hasName(R.Version(), "crt")) {
     skip_cases <- c(