Function TestMissingSurrogateLow

deep_spec_test.go:622–640

Verifies: SYS-REQ-061 [malformed] A lone high surrogate is malformed per RFC 8259/WHATWG; per DEFECT-260727-SNGT the parser matches encoding/json by substituting U+FFFD (NOT returning MalformedValueError). SYS-REQ-061's strict error-return is superseded for the lone-surrogate case by the encoding/js

(t *testing.T)

// MalformedValueError). SYS-REQ-061's strict error-return is superseded for
// the lone-surrogate case by the encoding/json parity fix.
func TestMissingSurrogateLow(t *testing.T) {
	// \uD800 alone (high surrogate, no low) → U+FFFD substitution, no error.
	got, err := ParseString([]byte(`\uD800`))
	if err != nil {
		t.Fatalf("ParseString(high surrogate only) error = %v, want nil (U+FFFD substitution)", err)
	}
	if got != "\uFFFD" {
		t.Fatalf("ParseString(high surrogate only) = %q, want %q (U+FFFD)", got, "\uFFFD")
	}

	// High surrogate followed by non-escape text → U+FFFD + literal text.
	got, err = ParseString([]byte(`\uD800abc`))
	if err != nil {
		t.Fatalf("ParseString(high surrogate + text) error = %v, want nil", err)
	}
	if got != "\uFFFDabc" {
		t.Fatalf("ParseString(high surrogate + text) = %q, want %q", got, "\uFFFDabc")
	}
}

// Verifies: SYS-REQ-062 [malformed]
// A high surrogate followed by an out-of-range second escape is a lone high