fix(ansi): tab is a zero-width character (#238)

Tabs should be treated as zero-width characters when wrapping text. Fixes: #237
charmbracelet · Nov 4, 2024 · 4179bb1 · 4179bb1
1 parent 12fe954
commit 4179bb1
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Showing 2 changed files with 5 additions and 2 deletions.
diff --git a/ansi/wrap.go b/ansi/wrap.go
@@ -83,7 +83,9 @@ func Hardwrap(s string, limit int, preserveSpace bool) string {
 			}
 
 			buf.WriteByte(b[i])
-			curWidth++
+			if action == parser.PrintAction {
+				curWidth++
+			}
 		default:
 			buf.WriteByte(b[i])
 		}

diff --git a/ansi/wrap_test.go b/ansi/wrap_test.go
@@ -19,7 +19,7 @@ var cases = []struct {
 	{"simple", "foobarfoo", 4, "foob\narfo\no", true},
 	{"lf", "f\no\nobar", 3, "f\no\noba\nr", true},
 	{"lf_space", "foo bar\n  baz", 3, "foo\n ba\nr\n  b\naz", true},
-	{"tab", "foo\tbar", 3, "foo\n\tba\nr", true},
+	{"tab", "foo\tbar", 3, "foo\n\tbar", true},
 	{"unicode_space", "foo\xc2\xa0bar", 3, "foo\nbar", false},
 	{"style_nochange", "\x1B[38;2;249;38;114mfoo\x1B[0m\x1B[38;2;248;248;242m \x1B[0m\x1B[38;2;230;219;116mbar\x1B[0m", 7, "\x1B[38;2;249;38;114mfoo\x1B[0m\x1B[38;2;248;248;242m \x1B[0m\x1B[38;2;230;219;116mbar\x1B[0m", true},
 	{"style", "\x1B[38;2;249;38;114m(\x1B[0m\x1B[38;2;248;248;242mjust another test\x1B[38;2;249;38;114m)\x1B[0m", 3, "\x1B[38;2;249;38;114m(\x1B[0m\x1B[38;2;248;248;242mju\nst \nano\nthe\nr t\nest\x1B[38;2;249;38;114m\n)\x1B[0m", true},
@@ -210,6 +210,7 @@ var wrapCases = []struct {
 	{"style_code_dont_affect_length", "\x1B[38;2;249;38;114mfoo\x1B[0m\x1B[38;2;248;248;242m \x1B[0m\x1B[38;2;230;219;116mbar\x1B[0m", "\x1B[38;2;249;38;114mfoo\x1B[0m\x1B[38;2;248;248;242m \x1B[0m\x1B[38;2;230;219;116mbar\x1B[0m", 7},
 	{"style_code_dont_get_wrapped", "\x1B[38;2;249;38;114m(\x1B[0m\x1B[38;2;248;248;242mjust another test\x1B[38;2;249;38;114m)\x1B[0m", "\x1b[38;2;249;38;114m(\x1b[0m\x1b[38;2;248;248;242mjust\nanother\ntest\x1b[38;2;249;38;114m)\x1b[0m", 7},
 	{"osc8_wrap", "สวัสดีสวัสดี\x1b]8;;https://example.com\x1b\\ สวัสดีสวัสดี\x1b]8;;\x1b\\", "สวัสดีสวัสดี\x1b]8;;https://example.com\x1b\\\nสวัสดีสวัสดี\x1b]8;;\x1b\\", 8},
+	{"tab", "foo\tbar", "foo\nbar", 3},
 }
 
 func TestWrap(t *testing.T) {