escape U+1B to avoid escape sequences in output

Author: evanw

internal/js_printer/js_printer.go

@@ -213,6 +213,9 @@ func (p *printer) printUnquotedUTF16(text []uint16, quote rune) {
 		case '\v':
 			js = append(js, "\\v"...)
 
+		case '\x1B':
+			js = append(js, "\\x1B"...)
+
 		case '\\':
 			js = append(js, "\\\\"...)
 

internal/js_printer/js_printer_test.go

@@ -391,6 +391,8 @@ func TestString(t *testing.T) {
 	expectPrinted(t, "let x = '\\01'", "let x = \"\x01\";\n")
 	expectPrinted(t, "let x = '\x10'", "let x = \"\x10\";\n")
 	expectPrinted(t, "let x = '\\x10'", "let x = \"\x10\";\n")
+	expectPrinted(t, "let x = '\x1B'", "let x = \"\\x1B\";\n")
+	expectPrinted(t, "let x = '\\x1B'", "let x = \"\\x1B\";\n")
 	expectPrinted(t, "let x = '\uABCD'", "let x = \"\uABCD\";\n")
 	expectPrinted(t, "let x = '\\uABCD'", "let x = \"\uABCD\";\n")
 	expectPrinted(t, "let x = '\U000123AB'", "let x = \"\U000123AB\";\n")