From ffb0f7c4f4cef3d09824bb936a089f3232727983 Mon Sep 17 00:00:00 2001
From: Alexander Rosenstock <alexander.rosenstock@web.de>
Date: Sun, 19 Jun 2022 20:13:05 +0200
Subject: [PATCH 01/12] refac: styles as named list of regexes

---
 R/object_name_linters.R                  | 5 +++--
 tests/testthat/test-object_name_linter.R | 3 +--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/R/object_name_linters.R b/R/object_name_linters.R
index 9ed2b2cc92..3f55b9a6c7 100644
--- a/R/object_name_linters.R
+++ b/R/object_name_linters.R
@@ -49,10 +49,11 @@ object_name_xpath <- local({
 #' @export
 object_name_linter <- function(styles = c("snake_case", "symbols")) {
   styles <- match.arg(styles, names(style_regexes), several.ok = TRUE)
+  styles <- style_regexes[styles]
 
   lint_message <- paste0(
     "Variable and function name style should be ",
-    glue::glue_collapse(styles, sep = ", ", last = " or "), "."
+    glue::glue_collapse(unique(names(styles)), sep = ", ", last = " or "), "."
   )
 
   Linter(function(source_expression) {
@@ -93,7 +94,7 @@ object_name_linter <- function(styles = c("snake_case", "symbols")) {
 }
 
 check_style <- function(nms, style, generics = character()) {
-  conforming <- re_matches(nms, style_regexes[[style]])
+  conforming <- re_matches(nms, style)
 
   # mark empty names and NA names as conforming
   conforming[!nzchar(nms) | is.na(conforming)] <- TRUE
diff --git a/tests/testthat/test-object_name_linter.R b/tests/testthat/test-object_name_linter.R
index 79bb8900ad..741ec79430 100644
--- a/tests/testthat/test-object_name_linter.R
+++ b/tests/testthat/test-object_name_linter.R
@@ -1,6 +1,5 @@
 test_that("styles are correctly identified", {
-  styles <- names(style_regexes)
-  do_style_check <- function(nms) lapply(styles, check_style, nms = nms)
+  do_style_check <- function(nms) lapply(unname(style_regexes), check_style, nms = nms)
   #                                            symbl   UpC   lowC   snake  SNAKE  dot    allow  ALLUP
   expect_identical(do_style_check("x"),   list(FALSE, FALSE, TRUE,  TRUE,  FALSE, TRUE,   TRUE,  FALSE))
   expect_identical(do_style_check(".x"),  list(FALSE, FALSE, TRUE,  TRUE,  FALSE, TRUE,   TRUE,  FALSE))

From aa087199f9008fff6f0a4e3327892749788efec9 Mon Sep 17 00:00:00 2001
From: Alexander Rosenstock <alexander.rosenstock@web.de>
Date: Sun, 19 Jun 2022 20:40:20 +0200
Subject: [PATCH 02/12] add regexes= argument and strip fewer symbols

---
 R/object_name_linters.R                  | 48 ++++++++++++------
 man/object_name_linter.Rd                |  6 ++-
 tests/testthat/test-object_name_linter.R | 64 ++++++++++++++++++++++++
 3 files changed, 103 insertions(+), 15 deletions(-)

diff --git a/R/object_name_linters.R b/R/object_name_linters.R
index 3f55b9a6c7..3c347ca3a4 100644
--- a/R/object_name_linters.R
+++ b/R/object_name_linters.R
@@ -44,12 +44,32 @@ object_name_xpath <- local({
 #' @param styles A subset of
 #'   \Sexpr[stage=render, results=rd]{lintr:::regexes_rd}. A name should
 #'   match at least one of these styles.
+#' @param regexes A (possibly named) character vector specifying a custom naming convention.
+#'   If named, the names will be used in the lint message. Otherwise, "custom" will be used as a name for the style.
+#'   Quotes (`` `"' ``) and the specials (`%` and trailing `<-`) are not considered part of the name to be matched.
 #' @evalRd rd_tags("object_name_linter")
 #' @seealso [linters] for a complete list of linters available in lintr.
 #' @export
-object_name_linter <- function(styles = c("snake_case", "symbols")) {
-  styles <- match.arg(styles, names(style_regexes), several.ok = TRUE)
-  styles <- style_regexes[styles]
+object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = character()) {
+  if (length(styles) > 0L) {
+    # Allow `object_name_linter(NULL, "my_regex")`
+    styles <- match.arg(styles, names(style_regexes), several.ok = TRUE)
+    styles <- style_regexes[styles]
+  } else {
+    styles <- list()
+  }
+  if (length(regexes) > 0L) {
+    if (!is.character(regexes)) {
+      stop("`regexes` must be a character vector.")
+    }
+    if (is.null(names(regexes))) {
+      names(regexes) <- "custom"
+    }
+    styles <- c(styles, as.list(regexes))
+  }
+  if (length(styles) == 0L) {
+    stop("At least one style must be specified using `styles` or `regexes`.")
+  }
 
   lint_message <- paste0(
     "Variable and function name style should be ",
@@ -110,8 +130,8 @@ check_style <- function(nms, style, generics = character()) {
       # If they are not conforming, but are S3 methods then ignore them
       conforming[!conforming][has_generic] <- TRUE
     }
-    # exclude namespace hooks like .onLoad, .Last.lib, etc (#500)
-    is_special <- is_special_function(nms[!conforming])
+    # exclude namespace hooks like .onLoad, .Last.lib, etc (#500) and ...
+    is_special <- is_special_function(nms[!conforming]) | nms[!conforming] == "..."
     conforming[!conforming][is_special] <- TRUE
   }
   conforming
@@ -119,8 +139,8 @@ check_style <- function(nms, style, generics = character()) {
 
 # Remove quotes or other things from names
 strip_names <- function(x) {
-  x <- re_substitutes(x, rex(start, some_of(".", quote, "`", "%", "$", "@")), "")
-  x <- re_substitutes(x, rex(some_of(quote, "`", "<", "-", "%", "$", "@"), end), "")
+  x <- re_substitutes(x, rex(start, some_of(quote, "`", "%")), "")
+  x <- re_substitutes(x, rex(some_of(quote, "`", "<", "-", "%"), end), "")
   x
 }
 
@@ -130,13 +150,13 @@ strip_names <- function(x) {
 #   (they don't strictly _have_ to be defined in base, so could in principle be removed).
 #   .Last.sys and .First.sys are part of base itself, so aren't included here.
 special_funs <- c(
-  "onLoad",
-  "onAttach",
-  "onUnload",
-  "onDetach",
-  "Last.lib",
-  "First",
-  "Last"
+  ".onLoad",
+  ".onAttach",
+  ".onUnload",
+  ".onDetach",
+  ".Last.lib",
+  ".First",
+  ".Last"
 )
 
 is_special_function <- function(x) {
diff --git a/man/object_name_linter.Rd b/man/object_name_linter.Rd
index a7aed7e8b4..0649fb8856 100644
--- a/man/object_name_linter.Rd
+++ b/man/object_name_linter.Rd
@@ -4,12 +4,16 @@
 \alias{object_name_linter}
 \title{Object name linter}
 \usage{
-object_name_linter(styles = c("snake_case", "symbols"))
+object_name_linter(styles = c("snake_case", "symbols"), regexes = character())
 }
 \arguments{
 \item{styles}{A subset of
 \Sexpr[stage=render, results=rd]{lintr:::regexes_rd}. A name should
 match at least one of these styles.}
+
+\item{regexes}{A (possibly named) character vector specifying a custom naming convention.
+If named, the names will be used in the lint message. Otherwise, "custom" will be used as a name for the style.
+Quotes (\verb{`"'}) and the specials (\verb{\%} and trailing \verb{<-}) are not considered part of the name to be matched.}
 }
 \description{
 Check that object names conform to a naming style.
diff --git a/tests/testthat/test-object_name_linter.R b/tests/testthat/test-object_name_linter.R
index 741ec79430..1c3e1c682c 100644
--- a/tests/testthat/test-object_name_linter.R
+++ b/tests/testthat/test-object_name_linter.R
@@ -150,3 +150,67 @@ test_that("object_name_linter won't fail if an imported namespace is unavailable
     3L
   )
 })
+
+test_that("object_name_linter supports custom regexes", {
+  # snake_case and symbols also allowed
+  linter <- object_name_linter(
+    regexes = c("shinyModule" = rex(start, lower, zero_or_more(alnum), "UI" %or% "Server", end))
+  )
+  msg <- rex::rex("Variable and function name style should be snake_case, symbols or shinyModule.")
+  linter2 <- object_name_linter(
+    styles = NULL,
+    regexes = c("shinyModule" = rex(start, lower, zero_or_more(alnum), "UI" %or% "Server", end))
+  )
+  msg2 <- rex::rex("Variable and function name style should be shinyModule.")
+
+  # Can't allow 0 styles
+  expect_error(
+    object_name_linter(NULL),
+    rex::rex("At least one style must be specified using `styles` or `regexes`.")
+  )
+
+  expect_lint(
+    trim_some("
+      snake_case <- 42L
+      \"%+%\" <- function(...) ..1 + ..2
+
+      myModuleUI <- function(id) {
+        # blah
+      }
+
+      myModuleServer <- function(id) {
+        # blah
+      }
+
+      myBadName <- 20L
+    "),
+    list(line_number = 12L, message = msg),
+    linter
+  )
+
+  expect_lint(
+    trim_some("
+      snake_case <- 42L
+      \"%+%\" <- function(...) ..1 + ..2
+
+      myModuleUI <- function(id) {
+        # blah
+      }
+
+      myModuleServer <- function(id) {
+        # blah
+      }
+
+      myBadName <- 20L
+    "),
+    list(
+      list(line_number = 1L, message = msg2),
+      list(line_number = 2L, message = msg2),
+      # argument "id" is linted if we only allow shinyModule names
+      list(line_number = 4L, column_number = 24L, message = msg2),
+      list(line_number = 8L, column_number = 28L, message = msg2),
+      list(line_number = 12L, message = msg2)
+    ),
+    linter2
+  )
+})

From d626c2a895f6f33795ac97205e364c91adbe927b Mon Sep 17 00:00:00 2001
From: Alexander Rosenstock <alexander.rosenstock@web.de>
Date: Sun, 19 Jun 2022 20:49:40 +0200
Subject: [PATCH 03/12] do not overwrite formal argument styles

---
 R/object_name_linters.R | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/R/object_name_linters.R b/R/object_name_linters.R
index 3c347ca3a4..37ee242075 100644
--- a/R/object_name_linters.R
+++ b/R/object_name_linters.R
@@ -54,9 +54,9 @@ object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = ch
   if (length(styles) > 0L) {
     # Allow `object_name_linter(NULL, "my_regex")`
     styles <- match.arg(styles, names(style_regexes), several.ok = TRUE)
-    styles <- style_regexes[styles]
+    style_list <- style_regexes[styles]
   } else {
-    styles <- list()
+    style_list <- list()
   }
   if (length(regexes) > 0L) {
     if (!is.character(regexes)) {
@@ -65,15 +65,15 @@ object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = ch
     if (is.null(names(regexes))) {
       names(regexes) <- "custom"
     }
-    styles <- c(styles, as.list(regexes))
+    style_list <- c(style_list, as.list(regexes))
   }
-  if (length(styles) == 0L) {
+  if (length(style_list) == 0L) {
     stop("At least one style must be specified using `styles` or `regexes`.")
   }
 
   lint_message <- paste0(
     "Variable and function name style should be ",
-    glue::glue_collapse(unique(names(styles)), sep = ", ", last = " or "), "."
+    glue::glue_collapse(unique(names(style_list)), sep = ", ", last = " or "), "."
   )
 
   Linter(function(source_expression) {
@@ -98,7 +98,7 @@ object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = ch
     )
     generics <- unique(generics[nzchar(generics)])
 
-    style_matches <- lapply(styles, function(style) {
+    style_matches <- lapply(style_list, function(style) {
       check_style(nms, style, generics)
     })
 

From 6822533c0e51f86d2e16864babd1795f506a2730 Mon Sep 17 00:00:00 2001
From: Michael Chirico <chiricom@google.com>
Date: Fri, 1 Jul 2022 22:34:11 -0700
Subject: [PATCH 04/12] grammar

---
 R/object_name_linters.R | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/R/object_name_linters.R b/R/object_name_linters.R
index 37ee242075..084b9d565d 100644
--- a/R/object_name_linters.R
+++ b/R/object_name_linters.R
@@ -46,7 +46,7 @@ object_name_xpath <- local({
 #'   match at least one of these styles.
 #' @param regexes A (possibly named) character vector specifying a custom naming convention.
 #'   If named, the names will be used in the lint message. Otherwise, "custom" will be used as a name for the style.
-#'   Quotes (`` `"' ``) and the specials (`%` and trailing `<-`) are not considered part of the name to be matched.
+#'   Quotes (`` `"' ``) and specials (`%` and trailing `<-`) are not considered part of the name to be matched.
 #' @evalRd rd_tags("object_name_linter")
 #' @seealso [linters] for a complete list of linters available in lintr.
 #' @export

From 8bc3e3ce6a22cd9fcc6f93320e8b584434e5e6cd Mon Sep 17 00:00:00 2001
From: Alexander Rosenstock <alexander.rosenstock@web.de>
Date: Mon, 11 Jul 2022 10:14:47 +0200
Subject: [PATCH 05/12] change behaviour of missing(styles) &&
 !missing(regexes), add tests for auto-named regexes.

fix test failure pertaining to is_linter not being a linter factory.
---
 R/object_name_linters.R                  | 11 ++++--
 man/object_name_linter.Rd                |  4 +-
 tests/testthat/test-linter_tags.R        |  2 +-
 tests/testthat/test-object_name_linter.R | 47 +++++++++++++++++-------
 4 files changed, 45 insertions(+), 19 deletions(-)

diff --git a/R/object_name_linters.R b/R/object_name_linters.R
index 084b9d565d..4aae9acb4b 100644
--- a/R/object_name_linters.R
+++ b/R/object_name_linters.R
@@ -47,11 +47,13 @@ object_name_xpath <- local({
 #' @param regexes A (possibly named) character vector specifying a custom naming convention.
 #'   If named, the names will be used in the lint message. Otherwise, "custom" will be used as a name for the style.
 #'   Quotes (`` `"' ``) and specials (`%` and trailing `<-`) are not considered part of the name to be matched.
+#'   Note that specifying `regexes` overrides the default `styles`. So if you want to combine `regexes` and `styles`,
+#'   both need to be explicitly specified.
 #' @evalRd rd_tags("object_name_linter")
 #' @seealso [linters] for a complete list of linters available in lintr.
 #' @export
 object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = character()) {
-  if (length(styles) > 0L) {
+  if ((!missing(styles) || missing(regexes)) && length(styles) > 0L) {
     # Allow `object_name_linter(NULL, "my_regex")`
     styles <- match.arg(styles, names(style_regexes), several.ok = TRUE)
     style_list <- style_regexes[styles]
@@ -62,9 +64,10 @@ object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = ch
     if (!is.character(regexes)) {
       stop("`regexes` must be a character vector.")
     }
-    if (is.null(names(regexes))) {
-      names(regexes) <- "custom"
-    }
+    rx_names <- names2(regexes)
+    rx_names[!nzchar(rx_names)] <- "custom"
+    names(regexes) <- rx_names
+
     style_list <- c(style_list, as.list(regexes))
   }
   if (length(style_list) == 0L) {
diff --git a/man/object_name_linter.Rd b/man/object_name_linter.Rd
index 0649fb8856..10fdd12f93 100644
--- a/man/object_name_linter.Rd
+++ b/man/object_name_linter.Rd
@@ -13,7 +13,9 @@ match at least one of these styles.}
 
 \item{regexes}{A (possibly named) character vector specifying a custom naming convention.
 If named, the names will be used in the lint message. Otherwise, "custom" will be used as a name for the style.
-Quotes (\verb{`"'}) and the specials (\verb{\%} and trailing \verb{<-}) are not considered part of the name to be matched.}
+Quotes (\verb{`"'}) and specials (\verb{\%} and trailing \verb{<-}) are not considered part of the name to be matched.
+Note that specifying \code{regexes} overrides the default \code{styles}. So if you want to combine \code{regexes} and \code{styles},
+both need to be explicitly specified.}
 }
 \description{
 Check that object names conform to a naming style.
diff --git a/tests/testthat/test-linter_tags.R b/tests/testthat/test-linter_tags.R
index 2850241ff2..06b16fe85b 100644
--- a/tests/testthat/test-linter_tags.R
+++ b/tests/testthat/test-linter_tags.R
@@ -59,7 +59,7 @@ test_that("available_linters matches the set of linters available from lintr", {
   # ensure that the contents of inst/lintr/linters.csv covers all _linter objects in our namespace
   expect_identical(sort(lintr_db$linter), sort(linters_in_namespace))
   # ensure that all _linter objects in our namespace are also exported
-  exported_linters <- grep("_linter$", getNamespaceExports("lintr"), value = TRUE)
+  exported_linters <- setdiff(grep("_linter$", getNamespaceExports("lintr"), value = TRUE), "is_linter")
   expect_identical(sort(linters_in_namespace), sort(exported_linters))
 })
 
diff --git a/tests/testthat/test-object_name_linter.R b/tests/testthat/test-object_name_linter.R
index 1c3e1c682c..7fad6b0796 100644
--- a/tests/testthat/test-object_name_linter.R
+++ b/tests/testthat/test-object_name_linter.R
@@ -152,16 +152,16 @@ test_that("object_name_linter won't fail if an imported namespace is unavailable
 })
 
 test_that("object_name_linter supports custom regexes", {
-  # snake_case and symbols also allowed
+  # disables default styles
   linter <- object_name_linter(
     regexes = c("shinyModule" = rex(start, lower, zero_or_more(alnum), "UI" %or% "Server", end))
   )
-  msg <- rex::rex("Variable and function name style should be snake_case, symbols or shinyModule.")
+  msg <- rex::rex("Variable and function name style should be shinyModule.")
   linter2 <- object_name_linter(
-    styles = NULL,
+    styles = c("snake_case", "symbols"),
     regexes = c("shinyModule" = rex(start, lower, zero_or_more(alnum), "UI" %or% "Server", end))
   )
-  msg2 <- rex::rex("Variable and function name style should be shinyModule.")
+  msg2 <- rex::rex("Variable and function name style should be snake_case, symbols or shinyModule.")
 
   # Can't allow 0 styles
   expect_error(
@@ -184,7 +184,14 @@ test_that("object_name_linter supports custom regexes", {
 
       myBadName <- 20L
     "),
-    list(line_number = 12L, message = msg),
+    list(
+      list(line_number = 1L, message = msg),
+      list(line_number = 2L, message = msg),
+      # argument "id" is linted if we only allow shinyModule names
+      list(line_number = 4L, column_number = 24L, message = msg),
+      list(line_number = 8L, column_number = 28L, message = msg),
+      list(line_number = 12L, message = msg)
+    ),
     linter
   )
 
@@ -203,14 +210,28 @@ test_that("object_name_linter supports custom regexes", {
 
       myBadName <- 20L
     "),
-    list(
-      list(line_number = 1L, message = msg2),
-      list(line_number = 2L, message = msg2),
-      # argument "id" is linted if we only allow shinyModule names
-      list(line_number = 4L, column_number = 24L, message = msg2),
-      list(line_number = 8L, column_number = 28L, message = msg2),
-      list(line_number = 12L, message = msg2)
-    ),
+    list(line_number = 12L, message = msg2),
     linter2
   )
+
+  # Default regex naming works
+  expect_lint(
+    trim_some("
+      a <- 42L
+      b <- 1L
+      c <- 2L
+    "),
+    list(line_number = 3L, message = rex::rex("Variable and function name style should be custom.")),
+    object_name_linter(regexes = c("^a$", "^b$"))
+  )
+
+  expect_lint(
+    trim_some("
+      a <- 42L
+      b <- 1L
+      c <- 2L
+    "),
+    list(line_number = 3L, message = rex::rex("Variable and function name style should be a or custom.")),
+    object_name_linter(regexes = c(a = "^a$", "^b$"))
+  )
 })

From 2f22a3c4c3968cbaf1eb055dd51266786933a4ce Mon Sep 17 00:00:00 2001
From: Indrajeet Patil <patilindrajeet.science@gmail.com>
Date: Sat, 8 Oct 2022 20:00:40 +0200
Subject: [PATCH 06/12] Update test-object_name_linter.R

---
 tests/testthat/test-object_name_linter.R | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/testthat/test-object_name_linter.R b/tests/testthat/test-object_name_linter.R
index 03f23edf86..01821064d2 100644
--- a/tests/testthat/test-object_name_linter.R
+++ b/tests/testthat/test-object_name_linter.R
@@ -1,6 +1,5 @@
 test_that("styles are correctly identified", {
-  styles <- names(lintr:::style_regexes)
-  do_style_check <- function(nms) lapply(styles, lintr:::check_style, nms = nms)
+  do_style_check <- function(nms) lapply(unname(style_regexes), check_style, nms = nms)
 
   #                                            symbl   UpC   lowC   snake  SNAKE  dot    allow  ALLUP
   expect_identical(do_style_check("x"),   list(FALSE, FALSE, TRUE,  TRUE,  FALSE, TRUE,   TRUE,  FALSE))

From 6665985830dbadbe91eb93796fb1f4086b02ce0d Mon Sep 17 00:00:00 2001
From: Alexander Rosenstock <alexander.rosenstock@web.de>
Date: Sat, 15 Oct 2022 15:11:52 +0200
Subject: [PATCH 07/12] split object_name_linters into object_length_linter.R
 and object_name_linter.R for consistency

---
 R/object_length_linter.R                      | 76 +++++++++++++++++
 ...ct_name_linters.R => object_name_linter.R} | 81 +------------------
 2 files changed, 78 insertions(+), 79 deletions(-)
 create mode 100644 R/object_length_linter.R
 rename R/{object_name_linters.R => object_name_linter.R} (73%)

diff --git a/R/object_length_linter.R b/R/object_length_linter.R
new file mode 100644
index 0000000000..9efd7eb6ca
--- /dev/null
+++ b/R/object_length_linter.R
@@ -0,0 +1,76 @@
+#' Object length linter
+#'
+#' Check that object names are not too long.
+#' The length of an object name is defined as the length in characters, after removing extraneous parts:
+#'
+#'  * generic prefixes for implementations of S3 generics, e.g. `as.data.frame.my_class` has length 8.
+#'  * leading `.`, e.g. `.my_hidden_function` has length 18.
+#'  * "%%" for infix operators, e.g. `%my_op%` has length 5.
+#'  * trailing `<-` for assignment functions, e.g. `my_attr<-` has length 7.
+#'
+#' Note that this behavior relies in part on having packages in your Imports available;
+#'   see the detailed note in [object_name_linter()] for more details.
+#'
+#' @param length maximum variable name length allowed.
+#'
+#' @examples
+#' # will produce lints
+#' lint(
+#'   text = "very_very_long_variable_name <- 1L",
+#'   linters = object_length_linter(length = 10L)
+#' )
+#'
+#' # okay
+#' lint(
+#'   text = "very_very_long_variable_name <- 1L",
+#'   linters = object_length_linter(length = 30L)
+#' )
+#'
+#' lint(
+#'   text = "var <- 1L",
+#'   linters = object_length_linter(length = 10L)
+#' )
+#'
+#' @evalRd rd_tags("object_length_linter")
+#' @seealso [linters] for a complete list of linters available in lintr.
+#' @export
+object_length_linter <- function(length = 30L) {
+  lint_message <- paste("Variable and function names should not be longer than", length, "characters.")
+
+  Linter(function(source_expression) {
+    if (!is_lint_level(source_expression, "file")) {
+      return(list())
+    }
+
+    xml <- source_expression$full_xml_parsed_content
+
+    assignments <- xml2::xml_find_all(xml, object_name_xpath)
+
+    # Retrieve assigned name
+    nms <- strip_names(
+      xml2::xml_text(assignments)
+    )
+
+    # run namespace_imports at run-time, not "compile" time to allow package structure to change
+    ns_imports <- namespace_imports(find_package(source_expression$filename))
+    generics <- strip_names(c(
+      declared_s3_generics(xml),
+      imported_s3_generics(ns_imports)$fun,
+      .base_s3_generics
+    ))
+    generics <- unique(generics[nzchar(generics)])
+
+    # Remove generic function names from generic implementations
+    # This only lints S3 implementations if the class names are too long, still lints generics if they are too long.
+    nms_stripped <- re_substitutes(nms, rex(start, or(generics), "."), "")
+
+    too_long <- nchar(nms_stripped) > length
+
+    xml_nodes_to_lints(
+      assignments[too_long],
+      source_expression = source_expression,
+      lint_message = lint_message,
+      type = "style"
+    )
+  })
+}
diff --git a/R/object_name_linters.R b/R/object_name_linter.R
similarity index 73%
rename from R/object_name_linters.R
rename to R/object_name_linter.R
index 436a7403aa..96c27a8e56 100644
--- a/R/object_name_linters.R
+++ b/R/object_name_linter.R
@@ -99,7 +99,7 @@ object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = ch
       stop("`regexes` must be a character vector.")
     }
     rx_names <- names2(regexes)
-    rx_names[!nzchar(rx_names)] <- "custom"
+    rx_names[!nzchar(rx_names)] <- paste0("/", regexes[!nzchar(rx_names)], "/") # auto-name regex "asd" -> /asd/
     names(regexes) <- rx_names
 
     style_list <- c(style_list, as.list(regexes))
@@ -109,7 +109,7 @@ object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = ch
   }
 
   lint_message <- paste0(
-    "Variable and function name style should be ",
+    "Variable and function name style should match ",
     glue::glue_collapse(unique(names(style_list)), sep = ", ", last = " or "), "."
   )
 
@@ -215,80 +215,3 @@ style_regexes <- list(
 )
 
 regexes_rd <- toString(paste0("\\sQuote{", names(style_regexes), "}"))
-
-#' Object length linter
-#'
-#' Check that object names are not too long.
-#' The length of an object name is defined as the length in characters, after removing extraneous parts:
-#'
-#'  * generic prefixes for implementations of S3 generics, e.g. `as.data.frame.my_class` has length 8.
-#'  * leading `.`, e.g. `.my_hidden_function` has length 18.
-#'  * "%%" for infix operators, e.g. `%my_op%` has length 5.
-#'  * trailing `<-` for assignment functions, e.g. `my_attr<-` has length 7.
-#'
-#' Note that this behavior relies in part on having packages in your Imports available;
-#'   see the detailed note in [object_name_linter()] for more details.
-#'
-#' @param length maximum variable name length allowed.
-#'
-#' @examples
-#' # will produce lints
-#' lint(
-#'   text = "very_very_long_variable_name <- 1L",
-#'   linters = object_length_linter(length = 10L)
-#' )
-#'
-#' # okay
-#' lint(
-#'   text = "very_very_long_variable_name <- 1L",
-#'   linters = object_length_linter(length = 30L)
-#' )
-#'
-#' lint(
-#'   text = "var <- 1L",
-#'   linters = object_length_linter(length = 10L)
-#' )
-#'
-#' @evalRd rd_tags("object_length_linter")
-#' @seealso [linters] for a complete list of linters available in lintr.
-#' @export
-object_length_linter <- function(length = 30L) {
-  lint_message <- paste("Variable and function names should not be longer than", length, "characters.")
-
-  Linter(function(source_expression) {
-    if (!is_lint_level(source_expression, "file")) {
-      return(list())
-    }
-
-    xml <- source_expression$full_xml_parsed_content
-
-    assignments <- xml2::xml_find_all(xml, object_name_xpath)
-
-    # Retrieve assigned name
-    nms <- strip_names(
-      xml2::xml_text(assignments)
-    )
-
-    # run namespace_imports at run-time, not "compile" time to allow package structure to change
-    ns_imports <- namespace_imports(find_package(source_expression$filename))
-    generics <- strip_names(c(
-      declared_s3_generics(xml),
-      imported_s3_generics(ns_imports)$fun,
-      .base_s3_generics
-    ))
-    generics <- unique(generics[nzchar(generics)])
-
-    # Remove generic function names from generic implementations
-    # This only lints S3 implementations if the class names are too long, still lints generics if they are too long.
-    nms_stripped <- re_substitutes(nms, rex(start, or(generics), "."), "")
-
-    too_long <- nchar(nms_stripped) > length
-
-    xml_nodes_to_lints(
-      assignments[too_long],
-      source_expression = source_expression,
-      lint_message = lint_message,
-      type = "style"
-    )
-  })
-}

From a2d445ea0d6702a1854f2d6a1f21d4b619464f77 Mon Sep 17 00:00:00 2001
From: Alexander Rosenstock <alexander.rosenstock@web.de>
Date: Sat, 15 Oct 2022 15:19:54 +0200
Subject: [PATCH 08/12] document(), add examples with regexes

---
 DESCRIPTION                              |  3 ++-
 R/object_name_linter.R                   | 10 ++++++++++
 man/object_length_linter.Rd              |  2 +-
 man/object_name_linter.Rd                | 12 +++++++++++-
 tests/testthat/test-object_name_linter.R | 16 ++++++++--------
 5 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index 6260ff61be..6d20a8b8f9 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -126,7 +126,8 @@ Collate:
     'nested_ifelse_linter.R'
     'no_tab_linter.R'
     'numeric_leading_zero_linter.R'
-    'object_name_linters.R'
+    'object_length_linter.R'
+    'object_name_linter.R'
     'object_usage_linter.R'
     'outer_negation_linter.R'
     'package_hooks_linter.R'
diff --git a/R/object_name_linter.R b/R/object_name_linter.R
index 96c27a8e56..6f0ffcb48b 100644
--- a/R/object_name_linter.R
+++ b/R/object_name_linter.R
@@ -67,6 +67,11 @@ object_name_xpath <- local({
 #'   linters = object_name_linter(styles = "dotted.case")
 #' )
 #'
+#' lint(
+#'   text = "asd <- 1L",
+#'   linters = object_name_linter(regexes = c(my_style = "F$", "f$"))
+#' )
+#'
 #' # okay
 #' lint(
 #'   text = "my_var <- 1L",
@@ -83,6 +88,11 @@ object_name_xpath <- local({
 #'   linters = object_name_linter(styles = c("dotted.case", "lowercase"))
 #' )
 #'
+#' lint(
+#'   text = "asdf <- 1L; asdF <- 1L",
+#'   linters = object_name_linter(regexes = c(my_style = "F$", "f$"))
+#' )
+#'
 #' @evalRd rd_tags("object_name_linter")
 #' @seealso [linters] for a complete list of linters available in lintr.
 #' @export
diff --git a/man/object_length_linter.Rd b/man/object_length_linter.Rd
index 39a5c70028..64c647e5cf 100644
--- a/man/object_length_linter.Rd
+++ b/man/object_length_linter.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/object_name_linters.R
+% Please edit documentation in R/object_length_linter.R
 \name{object_length_linter}
 \alias{object_length_linter}
 \title{Object length linter}
diff --git a/man/object_name_linter.Rd b/man/object_name_linter.Rd
index 81b9bea4ba..46e1d9a586 100644
--- a/man/object_name_linter.Rd
+++ b/man/object_name_linter.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/object_name_linters.R
+% Please edit documentation in R/object_name_linter.R
 \name{object_name_linter}
 \alias{object_name_linter}
 \title{Object name linter}
@@ -56,6 +56,11 @@ lint(
   linters = object_name_linter(styles = "dotted.case")
 )
 
+lint(
+  text = "asd <- 1L",
+  linters = object_name_linter(regexes = c(my_style = "F$", "f$"))
+)
+
 # okay
 lint(
   text = "my_var <- 1L",
@@ -72,6 +77,11 @@ lint(
   linters = object_name_linter(styles = c("dotted.case", "lowercase"))
 )
 
+lint(
+  text = "asdf <- 1L; asdF <- 1L",
+  linters = object_name_linter(regexes = c(my_style = "F$", "f$"))
+)
+
 }
 \seealso{
 \link{linters} for a complete list of linters available in lintr.
diff --git a/tests/testthat/test-object_name_linter.R b/tests/testthat/test-object_name_linter.R
index 8e1537234a..f57ed88795 100644
--- a/tests/testthat/test-object_name_linter.R
+++ b/tests/testthat/test-object_name_linter.R
@@ -54,7 +54,7 @@ test_that("linter ignores some objects", {
 })
 
 test_that("linter returns correct linting", {
-  lint_msg <- "Variable and function name style should be camelCase."
+  lint_msg <- "Variable and function name style should match camelCase."
   linter <- object_name_linter("camelCase")
 
   expect_lint("myObject <- 123", NULL, linter)
@@ -86,7 +86,7 @@ test_that("linter returns correct linting", {
 })
 
 test_that("linter accepts vector of styles", {
-  lint_msg <- "Variable and function name style should be camelCase or dotted.case."
+  lint_msg <- "Variable and function name style should match camelCase or dotted.case."
   linter <- object_name_linter(styles = c("camelCase", "dotted.case"))
 
   expect_lint(
@@ -99,7 +99,7 @@ test_that("linter accepts vector of styles", {
 test_that("dollar subsetting only lints the first expression", {
   # Regression test for #582
   linter <- object_name_linter()
-  lint_msg <- "Variable and function name style should be snake_case or symbols."
+  lint_msg <- "Variable and function name style should match snake_case or symbols."
 
   expect_lint("my_var$MY_COL <- 42L", NULL, linter)
   expect_lint("MY_VAR$MY_COL <- 42L", lint_msg, linter)
@@ -109,7 +109,7 @@ test_that("dollar subsetting only lints the first expression", {
 
 test_that("assignment targets of compound lhs are correctly identified", {
   linter <- object_name_linter()
-  lint_msg <- "Variable and function name style should be snake_case or symbols."
+  lint_msg <- "Variable and function name style should match snake_case or symbols."
 
   # (recursive) [, $, and [[ subsetting
   expect_lint("good_name[badName] <- badName2", NULL, linter)
@@ -161,12 +161,12 @@ test_that("object_name_linter supports custom regexes", {
   linter <- object_name_linter(
     regexes = c("shinyModule" = rex(start, lower, zero_or_more(alnum), "UI" %or% "Server", end))
   )
-  msg <- rex::rex("Variable and function name style should be shinyModule.")
+  msg <- rex::rex("Variable and function name style should match shinyModule.")
   linter2 <- object_name_linter(
     styles = c("snake_case", "symbols"),
     regexes = c("shinyModule" = rex(start, lower, zero_or_more(alnum), "UI" %or% "Server", end))
   )
-  msg2 <- rex::rex("Variable and function name style should be snake_case, symbols or shinyModule.")
+  msg2 <- rex::rex("Variable and function name style should match snake_case, symbols or shinyModule.")
 
   # Can't allow 0 styles
   expect_error(
@@ -226,7 +226,7 @@ test_that("object_name_linter supports custom regexes", {
       b <- 1L
       c <- 2L
     "),
-    list(line_number = 3L, message = rex::rex("Variable and function name style should be custom.")),
+    list(line_number = 3L, message = rex::rex("Variable and function name style should match /^a$/ or /^b$/.")),
     object_name_linter(regexes = c("^a$", "^b$"))
   )
 
@@ -236,7 +236,7 @@ test_that("object_name_linter supports custom regexes", {
       b <- 1L
       c <- 2L
     "),
-    list(line_number = 3L, message = rex::rex("Variable and function name style should be a or custom.")),
+    list(line_number = 3L, message = rex::rex("Variable and function name style should match a or /^b$/.")),
     object_name_linter(regexes = c(a = "^a$", "^b$"))
   )
 })

From 395b7e4d77861a9d6dac50ada58e2a45d7a6d931 Mon Sep 17 00:00:00 2001
From: Michael Chirico <chiricom@google.com>
Date: Sat, 15 Oct 2022 07:00:19 -0700
Subject: [PATCH 09/12] un-escape quote for readability

---
 tests/testthat/test-object_name_linter.R | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/testthat/test-object_name_linter.R b/tests/testthat/test-object_name_linter.R
index f57ed88795..ccb8e355e6 100644
--- a/tests/testthat/test-object_name_linter.R
+++ b/tests/testthat/test-object_name_linter.R
@@ -175,9 +175,9 @@ test_that("object_name_linter supports custom regexes", {
   )
 
   expect_lint(
-    trim_some("
+    trim_some('
       snake_case <- 42L
-      \"%+%\" <- function(...) ..1 + ..2
+      "%+%" <- function(...) ..1 + ..2
 
       myModuleUI <- function(id) {
         # blah
@@ -188,7 +188,7 @@ test_that("object_name_linter supports custom regexes", {
       }
 
       myBadName <- 20L
-    "),
+    '),
     list(
       list(line_number = 1L, message = msg),
       list(line_number = 2L, message = msg),

From bccf5951c914af11060816800f14b941726a88ca Mon Sep 17 00:00:00 2001
From: Michael Chirico <chiricom@google.com>
Date: Sat, 15 Oct 2022 07:04:16 -0700
Subject: [PATCH 10/12] again

---
 tests/testthat/test-object_name_linter.R | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/testthat/test-object_name_linter.R b/tests/testthat/test-object_name_linter.R
index ccb8e355e6..8bbda600f7 100644
--- a/tests/testthat/test-object_name_linter.R
+++ b/tests/testthat/test-object_name_linter.R
@@ -201,9 +201,9 @@ test_that("object_name_linter supports custom regexes", {
   )
 
   expect_lint(
-    trim_some("
+    trim_some('
       snake_case <- 42L
-      \"%+%\" <- function(...) ..1 + ..2
+      "%+%" <- function(...) ..1 + ..2
 
       myModuleUI <- function(id) {
         # blah
@@ -214,7 +214,7 @@ test_that("object_name_linter supports custom regexes", {
       }
 
       myBadName <- 20L
-    "),
+    '),
     list(line_number = 12L, message = msg2),
     linter2
   )

From 246b4f1dcabdf97a20d33ee9c430ccf4f435ca55 Mon Sep 17 00:00:00 2001
From: Alexander Rosenstock <alexander.rosenstock@web.de>
Date: Sat, 15 Oct 2022 16:20:56 +0200
Subject: [PATCH 11/12] fix documentation

---
 R/object_name_linter.R    | 6 ++++--
 man/object_name_linter.Rd | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/R/object_name_linter.R b/R/object_name_linter.R
index 6f0ffcb48b..0ab89a6dcf 100644
--- a/R/object_name_linter.R
+++ b/R/object_name_linter.R
@@ -24,6 +24,8 @@ object_name_xpath <- local({
 #' Check that object names conform to a naming style.
 #' The default naming styles are "snake_case" and "symbols".
 #'
+#' Quotes (`` `"' ``) and specials (`%` and trailing `<-`) are not considered part of the object name.
+#'
 #' Note when used in a package, in order to ignore objects imported
 #'   from other namespaces, this linter will attempt [getNamespaceExports()]
 #'   whenever an `import(PKG)` or `importFrom(PKG, ...)` statement is found
@@ -45,8 +47,8 @@ object_name_xpath <- local({
 #'   \Sexpr[stage=render, results=rd]{lintr:::regexes_rd}. A name should
 #'   match at least one of these styles.
 #' @param regexes A (possibly named) character vector specifying a custom naming convention.
-#'   If named, the names will be used in the lint message. Otherwise, "custom" will be used as a name for the style.
-#'   Quotes (`` `"' ``) and specials (`%` and trailing `<-`) are not considered part of the name to be matched.
+#'   If named, the names will be used in the lint message. Otherwise, the regexes enclosed by `/` will be used in the
+#'   lint message.
 #'   Note that specifying `regexes` overrides the default `styles`. So if you want to combine `regexes` and `styles`,
 #'   both need to be explicitly specified.
 #'
diff --git a/man/object_name_linter.Rd b/man/object_name_linter.Rd
index 46e1d9a586..ad5e9ebb45 100644
--- a/man/object_name_linter.Rd
+++ b/man/object_name_linter.Rd
@@ -12,8 +12,8 @@ object_name_linter(styles = c("snake_case", "symbols"), regexes = character())
 match at least one of these styles.}
 
 \item{regexes}{A (possibly named) character vector specifying a custom naming convention.
-If named, the names will be used in the lint message. Otherwise, "custom" will be used as a name for the style.
-Quotes (\verb{`"'}) and specials (\verb{\%} and trailing \verb{<-}) are not considered part of the name to be matched.
+If named, the names will be used in the lint message. Otherwise, the regexes enclosed by \code{/} will be used in the
+lint message.
 Note that specifying \code{regexes} overrides the default \code{styles}. So if you want to combine \code{regexes} and \code{styles},
 both need to be explicitly specified.}
 }
@@ -22,6 +22,8 @@ Check that object names conform to a naming style.
 The default naming styles are "snake_case" and "symbols".
 }
 \details{
+Quotes (\verb{`"'}) and specials (\verb{\%} and trailing \verb{<-}) are not considered part of the object name.
+
 Note when used in a package, in order to ignore objects imported
 from other namespaces, this linter will attempt \code{\link[=getNamespaceExports]{getNamespaceExports()}}
 whenever an \code{import(PKG)} or \code{importFrom(PKG, ...)} statement is found

From 1abdfdbd08e599a973291cd43d52e8e6d806ad15 Mon Sep 17 00:00:00 2001
From: Michael Chirico <chiricom@google.com>
Date: Sat, 15 Oct 2022 07:25:42 -0700
Subject: [PATCH 12/12] re-use nzchar output

---
 R/object_name_linter.R | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/R/object_name_linter.R b/R/object_name_linter.R
index 0ab89a6dcf..a7e37de2a0 100644
--- a/R/object_name_linter.R
+++ b/R/object_name_linter.R
@@ -111,7 +111,8 @@ object_name_linter <- function(styles = c("snake_case", "symbols"), regexes = ch
       stop("`regexes` must be a character vector.")
     }
     rx_names <- names2(regexes)
-    rx_names[!nzchar(rx_names)] <- paste0("/", regexes[!nzchar(rx_names)], "/") # auto-name regex "asd" -> /asd/
+    missing_name <- !nzchar(rx_names)
+    rx_names[missing_name] <- paste0("/", regexes[missing_name], "/") # auto-name regex "asd" -> /asd/
     names(regexes) <- rx_names
 
     style_list <- c(style_list, as.list(regexes))