Add examples to documentation: Part-9 (cleanup) (#1688)

* Examples for `fixed_regex_linter()`

* cleanup

* more cleanup

* review comments

* another example for fixed regex

NEWS.md

@@ -48,6 +48,8 @@
 
 * `sprintf_linter()` also applies to `gettextf()` (#1677, @MichaelChirico)
 
+* Documentation for all linters contains examples of code that does and does not produce lints (#1492, @IndrajeetPatil).
+
 ### New linters
 
 * `unnecessary_lambda_linter()`: detect unnecessary lambdas (anonymous functions), e.g.

R/assignment_linter.R

@@ -14,8 +14,10 @@
 #'   linters = assignment_linter()
 #' )
 #'
+#' code_lines <- "1 -> x\n2 ->> y"
+#' writeLines(code_lines)
 #' lint(
-#'   text = "1 -> x; 2 ->> y",
+#'   text = code_lines,
 #'   linters = assignment_linter()
 #' )
 #'
@@ -25,14 +27,18 @@
 #'   linters = assignment_linter()
 #' )
 #'
+#' code_lines <- "x <- 1\ny <<- 2"
+#' writeLines(code_lines)
 #' lint(
-#'   text = "x <- 1; y <<- 2",
+#'   text = code_lines,
 #'   linters = assignment_linter()
 #' )
 #'
 #' # customizing using arguments
+#' code_lines <- "1 -> x\n2 ->> y"
+#' writeLines(code_lines)
 #' lint(
-#'   text = "1 -> x; 2 ->> y",
+#'   text = code_lines,
 #'   linters = assignment_linter(allow_right_assign = TRUE)
 #' )
 #'

R/class_equals_linter.R

@@ -10,23 +10,23 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "is_lm <- class(x) == 'lm'",
+#'   text = 'is_lm <- class(x) == "lm"',
 #'   linters = class_equals_linter()
 #' )
 #'
 #' lint(
-#'   text = "if ('lm' %in% class(x)) is_lm <- TRUE",
+#'   text = 'if ("lm" %in% class(x)) is_lm <- TRUE',
 #'   linters = class_equals_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "is_lm <- inherits(x, 'lm')",
+#'   text = 'is_lm <- inherits(x, "lm")',
 #'   linters = class_equals_linter()
 #' )
 #'
 #' lint(
-#'   text = "if (inherits(x, 'lm')) is_lm <- TRUE",
+#'   text = 'if (inherits(x, "lm")) is_lm <- TRUE',
 #'   linters = class_equals_linter()
 #' )
 #'

R/condition_message_linter.R

@@ -12,28 +12,28 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "stop(paste('a string', 'another'))",
+#'   text = 'stop(paste("a string", "another")"',
 #'   linters = condition_message_linter()
 #' )
 #'
 #' lint(
-#'   text = "warning(paste0('a string', ' another'))",
+#'   text = 'warning(paste0("a string", " another")',
 #'   linters = condition_message_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "stop('a string', ' another')",
+#'   text = 'stop("a string", " another")',
 #'   linters = condition_message_linter()
 #' )
 #'
 #' lint(
-#'   text = "warning('a string', ' another')",
+#'   text = 'warning("a string", " another")',
 #'   linters = condition_message_linter()
 #' )
 #'
 #' lint(
-#'   text = "warning(paste('a string', 'another', sep = '-'))",
+#'   text = 'warning(paste("a string", "another", sep = "-"))',
 #'   linters = condition_message_linter()
 #' )
 #'

R/conjunct_test_linter.R

@@ -34,7 +34,7 @@
 #' )
 #'
 #' lint(
-#'   text = "stopifnot('x must be a logical scalar' = length(x) == 1 && is.logical(x) && !is.na(x))",
+#'   text = 'stopifnot("x must be a logical scalar" = length(x) == 1 && is.logical(x) && !is.na(x))',
 #'   linters = conjunct_test_linter(allow_named_stopifnot = TRUE)
 #' )
 #'

R/expect_named_linter.R

@@ -7,23 +7,23 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "expect_equal(names(x), 'a')",
+#'   text = 'expect_equal(names(x), "a")',
 #'   linters = expect_named_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "expect_named(x, 'a')",
+#'   text = 'expect_named(x, "a")',
 #'   linters = expect_named_linter()
 #' )
 #'
 #' lint(
-#'   text = "expect_equal(colnames(x), 'a')",
+#'   text = 'expect_equal(colnames(x), "a")',
 #'   linters = expect_named_linter()
 #' )
 #'
 #' lint(
-#'   text = "expect_equal(dimnames(x), 'a')",
+#'   text = 'expect_equal(dimnames(x), "a")',
 #'   linters = expect_named_linter()
 #' )
 #'

R/expect_s3_class_linter.R

@@ -8,23 +8,23 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "expect_equal(class(x), 'data.frame')",
+#'   text = 'expect_equal(class(x), "data.frame")',
 #'   linters = expect_s3_class_linter()
 #' )
 #'
 #' lint(
-#'   text = "expect_equal(class(x), 'numeric')",
+#'   text = 'expect_equal(class(x), "numeric")',
 #'   linters = expect_s3_class_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "expect_s3_class(x, 'data.frame')",
+#'   text = 'expect_s3_class(x, "data.frame")',
 #'   linters = expect_s3_class_linter()
 #' )
 #'
 #' lint(
-#'   text = "expect_type(x, 'double')",
+#'   text = 'expect_type(x, "double")',
 #'   linters = expect_s3_class_linter()
 #' )
 #'

R/expect_s4_class_linter.R

@@ -7,13 +7,13 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "expect_true(is(x, 'Matrix'))",
+#'   text = 'expect_true(is(x, "Matrix"))',
 #'   linters = expect_s4_class_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "expect_s4_class(x, 'Matrix')",
+#'   text = 'expect_s4_class(x, "Matrix")',
 #'   linters = expect_s4_class_linter()
 #' )
 #'

R/expect_type_linter.R

@@ -8,18 +8,18 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "expect_equal(typeof(x), 'double')",
+#'   text = 'expect_equal(typeof(x), "double")',
 #'   linters = expect_type_linter()
 #' )
 #'
 #' lint(
-#'   text = "expect_identical(typeof(x), 'double')",
+#'   text = 'expect_identical(typeof(x), "double")',
 #'   linters = expect_type_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "expect_type(x, 'double')",
+#'   text = 'expect_type(x, "double")',
 #'   linters = expect_type_linter()
 #' )
 #'

R/extraction_operator_linter.R

@@ -29,18 +29,18 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "iris['Species']",
+#'   text = 'iris["Species"]',
 #'   linters = extraction_operator_linter()
 #' )
 #'
 #' lint(
-#'   text = "iris$Species",
+#'   text = 'iris$Species',
 #'   linters = extraction_operator_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "iris[['Species']]",
+#'   text = 'iris[["Species"]]',
 #'   linters = extraction_operator_linter()
 #' )
 #'

R/fixed_regex_linter.R

@@ -10,6 +10,55 @@
 #'   likely cases. It should _never_ report false positives, however; please
 #'   report false positives as an error.
 #'
+#' @examples
+#' # will produce lints
+#' code_lines <- 'gsub("\\\\.", "", x)'
+#' writeLines(code_lines)
+#' lint(
+#'   text = code_lines,
+#'   linters = fixed_regex_linter()
+#' )
+#'
+#' lint(
+#'   text = 'grepl("a[*]b", x)',
+#'   linters = fixed_regex_linter()
+#' )
+#'
+#' code_lines <- 'stringr::str_subset(x, "\\\\$")'
+#' writeLines(code_lines)
+#' lint(
+#'   text = code_lines,
+#'   linters = fixed_regex_linter()
+#' )
+#'
+#' lint(
+#'   text = 'grepl("Munich", address)',
+#'   linters = fixed_regex_linter()
+#' )
+#'
+#' # okay
+#' code_lines <- 'gsub("\\\\.", "", x, fixed = TRUE)'
+#' writeLines(code_lines)
+#' lint(
+#'   text = code_lines,
+#'   linters = fixed_regex_linter()
+#' )
+#'
+#' lint(
+#'   text = 'grepl("a*b", x, fixed = TRUE)',
+#'   linters = fixed_regex_linter()
+#' )
+#'
+#' lint(
+#'   text = 'stringr::str_subset(x, stringr::fixed("$"))',
+#'   linters = fixed_regex_linter()
+#' )
+#'
+#' lint(
+#'   text = 'grepl("Munich", address, fixed = TRUE)',
+#'   linters = fixed_regex_linter()
+#' )
+#'
 #' @evalRd rd_tags("fixed_regex_linter")
 #' @seealso [linters] for a complete list of linters available in lintr.
 #' @export

R/is_numeric_linter.R

@@ -5,28 +5,28 @@
 #'
 #' NB: This linter plays well with [class_equals_linter()], which can help
 #'   avoid further `is.numeric()` equivalents like
-#'   any(class(x) == c("numeric", "integer"))`.
+#'   `any(class(x) == c("numeric", "integer"))`.
 #'
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "is.numeric(y) || is.integer(y)",
+#'   text = 'is.numeric(y) || is.integer(y)',
 #'   linters = is_numeric_linter()
 #' )
 #'
 #' lint(
-#'   text = "class(z) %in% c('numeric', 'integer')",
+#'   text = 'class(z) %in% c("numeric", "integer")',
 #'   linters = is_numeric_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "is.numeric(y) || is.factor(y)",
+#'   text = 'is.numeric(y) || is.factor(y)',
 #'   linters = is_numeric_linter()
 #' )
 #'
 #' lint(
-#'   text = "class(z) %in% c('numeric', 'integer', 'factor')",
+#'   text = 'class(z) %in% c("numeric", "integer", "factor")',
 #'   linters = is_numeric_linter()
 #' )
 #'

R/missing_argument_linter.R

@@ -8,23 +8,23 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "tibble(x = 'a', )",
+#'   text = 'tibble(x = "a", )',
 #'   linters = missing_argument_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "tibble(x = 'a')",
+#'   text = 'tibble(x = "a")',
 #'   linters = missing_argument_linter()
 #' )
 #'
 #' lint(
-#'   text = "tibble(x = 'a', )",
+#'   text = 'tibble(x = "a", )',
 #'   linters = missing_argument_linter(except = "tibble")
 #' )
 #'
 #' lint(
-#'   text = "tibble(x = 'a', )",
+#'   text = 'tibble(x = "a", )',
 #'   linters = missing_argument_linter(allow_trailing = TRUE)
 #' )
 #'

R/nested_ifelse_linter.R

@@ -16,18 +16,18 @@
 #' @examples
 #' # will produce lints
 #' lint(
-#'   text = "ifelse(x == 'a', 1L, ifelse(x == 'b', 2L, 3L))",
+#'   text = 'ifelse(x == "a", 1L, ifelse(x == "b", 2L, 3L))',
 #'   linters = nested_ifelse_linter()
 #' )
 #'
 #' # okay
 #' lint(
-#'   text = "dplyr::case_when(x == 'a' ~ 1L, x == 'b' ~ 2L, TRUE ~ 3L)",
+#'   text = 'dplyr::case_when(x == "a" ~ 1L, x == "b" ~ 2L, TRUE ~ 3L)',
 #'   linters = nested_ifelse_linter()
 #' )
 #'
 #' lint(
-#'   text = "data.table::fcase(x == 'a', 1L, x == 'b', 2L, default = 3L)",
+#'   text = 'data.table::fcase(x == "a", 1L, x == "b", 2L, default = 3L)',
 #'   linters = nested_ifelse_linter()
 #' )
 #'

R/package_hooks_linter.R

@@ -35,7 +35,7 @@
 #' )
 #'
 #' lint(
-#'   text = ".onAttach <- function(lib, pkg) { loadNamespace('foo') }",
+#'   text = '.onAttach <- function(lib, pkg) { loadNamespace("foo") }',
 #'   linters = package_hooks_linter()
 #' )
 #'