Add IsZero method to UUID type for MongoDB omitzero support (#226)

* Initial plan

* Add IsZero method to UUID type for MongoDB omitzero support

Co-authored-by: cameracker <[email protected]>

* Expand IsZero documentation to reference bsoncodec.Zeroer interface and GitHub issue

Co-authored-by: cameracker <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: cameracker <[email protected]>
Co-authored-by: Cameron Ackerman <[email protected]>

Author: Copilot

uuid.go

@@ -192,6 +192,13 @@ func (u UUID) IsNil() bool {
 	return u == Nil
 }
 
+// IsZero returns if the UUID is equal to the zero UUID (same as IsNil).
+// This method is provided to satisfy the bsoncodec.Zeroer interface for MongoDB
+// omitzero tag support. See: https://github.com/gofrs/uuid/issues/224
+func (u UUID) IsZero() bool {
+	return u == Nil
+}
+
 // Version returns the algorithm version used to generate the UUID.
 func (u UUID) Version() byte {
 	return u[6] >> 4

uuid_test.go

@@ -31,6 +31,7 @@ import (
 
 func TestUUID(t *testing.T) {
 	t.Run("IsNil", testUUIDIsNil)
+	t.Run("IsZero", testUUIDIsZero)
 	t.Run("Bytes", testUUIDBytes)
 	t.Run("String", testUUIDString)
 	t.Run("Version", testUUIDVersion)
@@ -49,6 +50,24 @@ func testUUIDIsNil(t *testing.T) {
 	}
 }
 
+func testUUIDIsZero(t *testing.T) {
+	// Test zero UUID
+	u := UUID{}
+	got := u.IsZero()
+	want := true
+	if got != want {
+		t.Errorf("%v.IsZero() = %t, want %t", u, got, want)
+	}
+
+	// Test non-zero UUID
+	nonZeroUUID := NamespaceDNS // Use a known non-zero UUID
+	got = nonZeroUUID.IsZero()
+	want = false
+	if got != want {
+		t.Errorf("%v.IsZero() = %t, want %t", nonZeroUUID, got, want)
+	}
+}
+
 func testUUIDBytes(t *testing.T) {
 	got := codecTestUUID.Bytes()
 	want := codecTestData