1 files changed, 340 insertions, 0 deletions
diff --git a/go/snowflake_test.go b/go/snowflake_test.go
new file mode 100644
index 0000000..e69644c
--- /dev/null
+++ b/go/snowflake_test.go
@@ -0,0 +1,340 @@
+package snowflake
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func TestNew(t *testing.T) {
+	s := New()
+	if s.IsZero() {
+		t.Error("New() returned zero Snowflake")
+	}
+}
+
+func TestNewUnique(t *testing.T) {
+	seen := make(map[string]bool, 1000)
+
+	for i := 0; i < 1000; i++ {
+		s := New()
+
+		str := s.String()
+		if seen[str] {
+			t.Fatalf("duplicate ID generated: %s", str)
+		}
+		seen[str] = true
+	}
+}
+
+func TestIsZero(t *testing.T) {
+	zero := Zero()
+	if !zero.IsZero() {
+		t.Error("Zero Snowflake should be zero")
+	}
+
+	nonZero := New()
+	if nonZero.IsZero() {
+		t.Error("New Snowflake should not be zero")
+	}
+}
+
+func TestStringRoundTrip(t *testing.T) {
+	original := New()
+	str := original.String()
+	parsed, err := FromString(str)
+	if err != nil {
+		t.Fatalf("FromString failed: %v", err)
+	}
+
+	if parsed != original {
+		t.Errorf("round-trip mismatch: original=%+v, parsed=%+v", original, parsed)
+	}
+}
+
+func TestStringRoundTripMany(t *testing.T) {
+	for i := 0; i < 100; i++ {
+		original := New()
+
+		str := original.String()
+		parsed, err := FromString(str)
+		if err != nil {
+			t.Fatalf("iteration %d: FromString failed: %v", i, err)
+		}
+		if parsed != original {
+			t.Fatalf("iteration %d: round-trip mismatch", i)
+		}
+	}
+}
+
+func TestFromStringInvalidChars(t *testing.T) {
+	_, err := FromString("!!invalid!!")
+	if err != ErrInvalidEncoding {
+		t.Errorf("expected ErrInvalidEncoding, got: %v", err)
+	}
+}
+
+func TestFromStringEmpty(t *testing.T) {
+	s, err := FromString("")
+	if err != nil {
+		t.Errorf("unexpected error for empty string: %v", err)
+	}
+	if !s.IsZero() {
+		t.Error("empty string should produce zero Snowflake")
+	}
+}
+
+func TestFromStringTooLong(t *testing.T) {
+	_, err := FromString("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")
+	if err != ErrInvalidEncoding {
+		t.Errorf("expected ErrInvalidEncoding for overflow, got: %v", err)
+	}
+}
+
+func TestHexString(t *testing.T) {
+	s := New()
+	hex := s.Hex()
+
+	if len(hex) != IDByteSize*2 {
+		t.Errorf("expected hex length %d, got %d", IDByteSize*2, len(hex))
+	}
+
+	for _, c := range hex {
+		if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f')) {
+			t.Errorf("invalid hex character: %c", c)
+		}
+	}
+}
+
+func TestZeroString(t *testing.T) {
+	zero := Zero()
+	str := zero.String()
+	if str != "0" {
+		t.Errorf("Zero Snowflake should stringify to %q, got: %q", "0", str)
+	}
+
+	parsed, err := FromString(str)
+	if err != nil {
+		t.Fatalf("FromString(%q) failed: %v", str, err)
+	}
+	if !parsed.IsZero() {
+		t.Error("FromString(Zero().String()) should round-trip to zero")
+	}
+}
+
+func TestHexRoundTrip(t *testing.T) {
+	original := New()
+	hex := original.Hex()
+	parsed, err := FromHex(hex)
+	if err != nil {
+		t.Fatalf("FromHex failed: %v", err)
+	}
+	if parsed != original {
+		t.Error("hex round-trip mismatch")
+	}
+}
+
+func TestFromHexInvalid(t *testing.T) {
+	_, err := FromHex("xyz")
+	if err == nil {
+		t.Error("expected error for invalid hex")
+	}
+}
+
+func TestFromHexWrongLength(t *testing.T) {
+	_, err := FromHex("01")
+	if err != ErrInvalidIDLength {
+		t.Errorf("expected ErrInvalidIDLength, got: %v", err)
+	}
+}
+
+func TestMarshalText(t *testing.T) {
+	s := New()
+	text, err := s.MarshalText()
+	if err != nil {
+		t.Fatalf("MarshalText failed: %v", err)
+	}
+
+	var decoded Snowflake
+	err = decoded.UnmarshalText(text)
+	if err != nil {
+		t.Fatalf("UnmarshalText failed: %v", err)
+	}
+
+	if decoded != s {
+		t.Error("text marshal/unmarshal mismatch")
+	}
+}
+
+func TestUnmarshalTextInvalid(t *testing.T) {
+	var s Snowflake
+	err := s.UnmarshalText([]byte("!!!"))
+	if err == nil {
+		t.Error("expected error for invalid text")
+	}
+}
+
+func TestMarshalJSON(t *testing.T) {
+	s := New()
+	data, err := s.MarshalJSON()
+	if err != nil {
+		t.Fatalf("MarshalJSON failed: %v", err)
+	}
+
+	var decoded Snowflake
+	err = json.Unmarshal(data, &decoded)
+	if err != nil {
+		t.Fatalf("json.Unmarshal failed: %v", err)
+	}
+
+	if decoded != s {
+		t.Error("JSON marshal/unmarshal mismatch")
+	}
+}
+
+func TestUnmarshalJSONMissingQuotes(t *testing.T) {
+	var s Snowflake
+	err := s.UnmarshalJSON([]byte(`invalid`))
+	if err != ErrInvalidEncoding {
+		t.Errorf("expected ErrInvalidEncoding, got: %v", err)
+	}
+}
+
+func TestUnmarshalJSONEmpty(t *testing.T) {
+	var s Snowflake
+	err := s.UnmarshalJSON([]byte(`""`))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !s.IsZero() {
+		t.Error("empty JSON string should produce zero Snowflake")
+	}
+}
+
+func TestUnmarshalJSONInvalidInner(t *testing.T) {
+	var s Snowflake
+	err := s.UnmarshalJSON([]byte(`"!!!"`))
+	if err != ErrInvalidEncoding {
+		t.Errorf("expected ErrInvalidEncoding for invalid inner content, got: %v", err)
+	}
+}
+
+func TestDriverValue(t *testing.T) {
+	s := New()
+	val, err := s.Value()
+	if err != nil {
+		t.Fatalf("Value failed: %v", err)
+	}
+
+	bytes, ok := val.([]byte)
+	if !ok {
+		t.Fatal("Value should return []byte")
+	}
+
+	if len(bytes) != IDByteSize {
+		t.Errorf("expected byte length %d, got %d", IDByteSize, len(bytes))
+	}
+}
+
+func TestDriverScan(t *testing.T) {
+	original := New()
+	bytes := make([]byte, IDByteSize)
+	copy(bytes, original.bytes[:])
+
+	var s Snowflake
+	if err := s.Scan(bytes); err != nil {
+		t.Fatalf("Scan failed: %v", err)
+	}
+
+	if s != original {
+		t.Error("Scan produced mismatched value")
+	}
+}
+
+func TestDriverScanString(t *testing.T) {
+	original := New()
+	bytes := make([]byte, IDByteSize)
+	copy(bytes, original.bytes[:])
+
+	var s Snowflake
+	if err := s.Scan(string(bytes)); err != nil {
+		t.Fatalf("Scan(string) failed: %v", err)
+	}
+
+	if s != original {
+		t.Error("Scan(string) produced mismatched value")
+	}
+}
+
+func TestDriverScanNil(t *testing.T) {
+	var s Snowflake
+	err := s.Scan(nil)
+	if err != nil {
+		t.Fatalf("Scan(nil) failed: %v", err)
+	}
+
+	if !s.IsZero() {
+		t.Error("Scan(nil) should produce zero Snowflake")
+	}
+}
+
+func TestDriverScanWrongLength(t *testing.T) {
+	var s Snowflake
+	err := s.Scan([]byte{1, 2, 3})
+	if err != ErrInvalidIDLength {
+		t.Errorf("expected ErrInvalidIDLength, got: %v", err)
+	}
+}
+
+func TestDriverScanZeroBytes(t *testing.T) {
+	var s Snowflake
+	zeroBytes := make([]byte, IDByteSize)
+	err := s.Scan(zeroBytes)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !s.IsZero() {
+		t.Error("Scan with all-zero bytes should produce zero Snowflake")
+	}
+}
+
+func TestDriverScanUnsupportedType(t *testing.T) {
+	var s Snowflake
+	err := s.Scan(42)
+	if err == nil {
+		t.Error("expected error for unsupported type")
+	}
+}
+
+func TestJSONEmbedding(t *testing.T) {
+	type Wrapper struct {
+		Name string     `json:"name"`
+		ID   Snowflake  `json:"id"`
+		Ref  *Snowflake `json:"ref,omitempty"`
+	}
+
+	s := New()
+	w := Wrapper{
+		Name: "test",
+		ID:   s,
+		Ref:  &s,
+	}
+
+	data, err := json.Marshal(&w)
+	if err != nil {
+		t.Fatalf("marshal failed: %v", err)
+	}
+
+	var decoded Wrapper
+	err = json.Unmarshal(data, &decoded)
+	if err != nil {
+		t.Fatalf("unmarshal failed: %v", err)
+	}
+
+	if decoded.ID != s {
+		t.Error("embedded ID mismatch")
+	}
+
+	if decoded.Ref == nil || *decoded.Ref != s {
+		t.Error("embedded ref mismatch")
+	}
+}