Fix ansi_strwrap edge cases

When `\f` is inside ANSI markup.
r-lib · Oct 21, 2021 · 582dd41 · 582dd41
1 parent 92625f7
commit 582dd41
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Showing 2 changed files with 16 additions and 2 deletions.
diff --git a/R/ansiex.R b/R/ansiex.R
@@ -502,7 +502,7 @@ ansi_strwrap <- function(x, width = console_width(), indent = 0,
   smark <- paste0("\n\n", mark, "\n\n")
   x <- gsub("\f", smark, x, fixed = TRUE, useBytes = TRUE)
   fix_ff <- function(x) {
-    rem <- which(x == mark)
+    rem <- which(ansi_strip(x) == mark)
     if (length(rem)) {
       x[-c(rem - 1, rem, rem + 1)]
     } else {
@@ -549,7 +549,10 @@ ansi_strwrap <- function(x, width = console_width(), indent = 0,
   while (xsidx <= xslen) {
     xsc <- substr(xs, xsidx, xsidx)
     xwc <- substr(xw[xwidx[1]], xwidx[2], xwidx[2])
-    if (xsc == xwc) {
+    if (is.na(xwc)) {
+      # colored trailing white space in input?
+      xsidx <- xsidx + 1L
+    } else if (xsc == xwc) {
       xsidx <- xsidx + 1L
       xwidx[2] <- xwidx[2] + 1L
     } else if (xsc %in% c(" ", "\n", "\t")) {

diff --git a/tests/testthat/test-ansiex.R b/tests/testthat/test-ansiex.R
@@ -519,6 +519,17 @@ test_that("ansi_strwrap newlines", {
   )
 })
 
+test_that("ansi_strwrap and \f edge cases", {
+  expect_equal(
+    ansi_strwrap("\033[32mfoo\fbar\033[39m"),
+    ansi_string(c("\033[32mfoo\033[39m", "\033[32mbar\033[39m"))
+  )
+  expect_equal(
+    ansi_strwrap("\033[32m\ffoo\f\033[39m"),
+    ansi_string(c("", "\033[32mfoo\033[39m"))
+  )
+})
+
 test_that_cli(configs = c("plain", "ansi"), "ansi_strtrim", {
   withr::local_options(c(cli.unicode = FALSE))
   setup_unicode_width_fix()