pkg/parse: Improve coverage of quote.go.

pkg/parse/quote_test.go

@@ -25,6 +25,9 @@ func TestQuote(t *testing.T) {
 		// Double quote when there is unprintable char.
 		Args("a\nb").Rets(`"a\nb"`),
 		Args("\x1b\"\\").Rets(`"\e\"\\"`),
+		Args("\x00").Rets(`"\x00"`),
+		Args("\u0600").Rets(`"\u0600"`),         // Arabic number sign
+		Args("\U000110BD").Rets(`"\U000110bd"`), // Kathi number sign
 
 		// Commas and equal signs are always quoted, so that the quoted string is
 		// safe for use everywhere.
@@ -33,6 +36,21 @@ func TestQuote(t *testing.T) {
 	})
 }
 
+func TestQuoteAs(t *testing.T) {
+	Test(t, Fn("QuoteAs", QuoteAs).ArgsFmt("(%q, %s)").RetsFmt("(%q, %s)"), Table{
+		// DoubleQuote is always respected.
+		Args("", DoubleQuoted).Rets(`""`, DoubleQuoted),
+		Args("a", DoubleQuoted).Rets(`"a"`, DoubleQuoted),
+
+		// SingleQuoted is respected when there is no unprintable character.
+		Args("", SingleQuoted).Rets(`''`, SingleQuoted),
+		Args("a", SingleQuoted).Rets(`'a'`, SingleQuoted),
+		Args("\n", SingleQuoted).Rets(`"\n"`, DoubleQuoted),
+
+		// Bareword tested above in TestQuote.
+	})
+}
+
 func TestQuoteVariableName(t *testing.T) {
 	Test(t, Fn("QuoteVariableName", QuoteVariableName).ArgsFmt("(%q)").RetsFmt("%q"), Table{
 		Args("").Rets("''"),