new width= parameter for output methods (#2369)

* new width= parameter for output methods

* workaround for GHA

* delint

Author: MichaelChirico

NEWS.md

@@ -30,6 +30,7 @@
 * `unnecessary_lambda_linter` is extended to encourage vectorized comparisons where possible, e.g. `sapply(x, sum) > 0` instead of `sapply(x, function(x) sum(x) > 0)` (part of #884, @MichaelChirico). Toggle this behavior with argument `allow_comparison`.
 * `backport_linter()` is slightly faster by moving expensive computations outside the linting function (#2339, #2348, @AshesITR and @MichaelChirico).
 * `Linter()` has a new argument `linter_level` (default `NA`). This is used by `lint()` to more efficiently check for expression levels than the idiom `if (!is_lint_level(...)) { return(list()) }` (#2351, @AshesITR).
+* `format()` and `print()` methods for `lint` and `lints` classes get a new option `width` to control the printing width of lint messages (#1884, @MichaelChirico). The default is controlled by a new option `lintr.format_width`; if unset, no wrapping occurs (matching earlier behavior).
 
 ### New linters
 

R/methods.R

@@ -1,5 +1,5 @@
 #' @export
-format.lint <- function(x, ...) {
+format.lint <- function(x, ..., width = getOption("lintr.format_width")) {
   if (requireNamespace("cli", quietly = TRUE)) {
     color <- switch(x$type,
       warning = cli::col_magenta,
@@ -15,7 +15,7 @@ format.lint <- function(x, ...) {
     # nocov end
   }
 
-  paste0(
+  annotated_msg <- paste0(
     emph(
       x$filename, ":",
       as.character(x$line_number), ":",
@@ -24,7 +24,15 @@ format.lint <- function(x, ...) {
     ),
     color(x$type, ": ", sep = ""),
     "[", x$linter, "] ",
-    emph(x$message), "\n",
+    emph(x$message)
+  )
+
+  if (!is.null(width)) {
+    annotated_msg <- paste(strwrap(annotated_msg, exdent = 4L, width = width), collapse = "\n")
+  }
+
+  paste0(
+    annotated_msg, "\n",
     # swap tabs for spaces for #528 (sorry Richard Hendricks)
     chartr("\t", " ", x$line), "\n",
     highlight_string(x$message, x$column_number, x$ranges),
@@ -34,7 +42,7 @@ format.lint <- function(x, ...) {
 
 #' @export
 print.lint <- function(x, ...) {
-  cat(format(x))
+  cat(format(x, ...))
   invisible(x)
 }
 
@@ -68,8 +76,8 @@ markdown <- function(x, info, ...) {
 }
 
 #' @export
-format.lints <- function(x, ...) {
-  paste(vapply(x, format, character(1L)), collapse = "\n")
+format.lints <- function(x, ..., width = getOption("lintr.format_width")) {
+  paste(vapply(x, format, character(1L), width = width), collapse = "\n")
 }
 
 #' @export

tests/testthat/test-methods.R

@@ -157,3 +157,43 @@ test_that("as.data.table.list is _not_ dispatched directly", {
   lints <- lint(text = "a = 1", linters = assignment_linter())
   expect_identical(nrow(data.table::as.data.table(lints)), 1L)
 })
+
+local({
+  # avoid impact of CLI mark-up on strwrap output.
+  #   (testthat, or cli, already do so, but force it explicitly here for emphasis)
+  withr::local_options(c(cli.num_colors = 0L))
+  # force "default" print method even on GHA
+  withr::local_envvar(c(GITHUB_ACTIONS = NA))
+
+  test_linter <- make_linter_from_xpath("*[1]", lint_message = "The quick brown fox jumps over the lazy dog.")
+
+  lints <- lint(text = "a", linters = test_linter())
+  lint <- lints[[1L]]
+
+  wrapped_strings <- c(
+    "[test_linter]\n    The\n    quick\n    brown\n    fox\n    jumps\n    over\n    the\n    lazy\n    dog.",
+    "[test_linter]\n    The quick brown\n    fox jumps over\n    the lazy dog.",
+    "[test_linter] The\n    quick brown fox jumps over the lazy\n    dog.",
+    "[test_linter] The quick brown fox jumps over the lazy dog."
+  )
+
+  patrick::with_parameters_test_that(
+    "format.lint, format.lints, print.lint, print.lints support optional message wrapping",
+    {
+      expect_match(format(lint, width = width), wrapped_string, fixed = TRUE)
+      expect_match(format(lints, width = width), wrapped_string, fixed = TRUE)
+      expect_output(print(lint, width = width), wrapped_string, fixed = TRUE)
+      expect_output(print(lints, width = width), wrapped_string, fixed = TRUE)
+
+      withr::with_options(c(lintr.format_width = width), {
+        expect_match(format(lint), wrapped_string, fixed = TRUE)
+        expect_match(format(lints), wrapped_string, fixed = TRUE)
+        expect_output(print(lint), wrapped_string, fixed = TRUE)
+        expect_output(print(lints), wrapped_string, fixed = TRUE)
+      })
+    },
+    .test_name = c(10L, 20L, 40L, 80L),
+    width = c(10L, 20L, 40L, 80L),
+    wrapped_string = wrapped_strings
+  )
+})