add uuid_v7 function with specified timestamp

internal/bloblang/query/functions.go

@@ -923,18 +923,32 @@ var _ = registerSimpleFunction(
 	},
 )
 
-var _ = registerSimpleFunction(
+var _ = registerFunction(
 	NewFunctionSpec(
 		FunctionCategoryGeneral, "uuid_v7",
 		"Generates a new time ordered UUID each time it is invoked and prints a string representation.",
 		NewExampleSpec("", `root.id = uuid_v7()`),
-	),
-	func(_ FunctionContext) (any, error) {
-		u7, err := uuid.NewV7()
+		NewExampleSpec("It is also possible to specify the timestamp for the uuid_v7", `root.id = uuid_v7(now().ts_sub_iso8601("PT1M"))`),
+	).Param(ParamTimestamp("time", "An optional timestamp to use for the time ordered portion of the UUID.").Optional()),
+	func(args *ParsedParams) (Function, error) {
+		time, err := args.FieldOptionalTimestamp("time")
 		if err != nil {
-			panic(err)
+			return nil, err
 		}
-		return u7.String(), nil
+		return ClosureFunction("function uuid_v7", func(fctx FunctionContext) (any, error) {
+			if time == nil {
+				u7, err := uuid.NewV7()
+				if err != nil {
+					return nil, fmt.Errorf("unable to generate uuid v7: %w", err)
+				}
+				return u7.String(), nil
+			}
+			u7, err := uuid.NewV7AtTime(*time)
+			if err != nil {
+				return nil, fmt.Errorf("unable to generate uuid v7 at time %s: %w", *time, err)
+			}
+			return u7.String(), nil
+		}, nil), nil
 	},
 )
 

internal/bloblang/query/functions_test.go

@@ -8,7 +8,9 @@ import (
 	"math"
 	"sync"
 	"testing"
+	"time"
 
+	"github.com/gofrs/uuid/v5"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -244,6 +246,33 @@ func TestFunctionTargets(t *testing.T) {
 	}
 }
 
+func TestUUIDV7Function(t *testing.T) {
+	e, err := InitFunctionHelper("uuid_v7")
+	require.NoError(t, err)
+
+	res, err := e.Exec(FunctionContext{})
+	require.NoError(t, err)
+	require.IsType(t, "", res)
+	u7 := uuid.FromStringOrNil(res.(string))
+	assert.Equal(t, u7.Version(), byte(7))
+}
+
+func TestUUIDV7FunctionAtTime(t *testing.T) {
+	ts := time.Now().Add(-5 * time.Hour)
+	e, err := InitFunctionHelper("uuid_v7", ts)
+	require.NoError(t, err)
+
+	res, err := e.Exec(FunctionContext{})
+	require.NoError(t, err)
+	require.IsType(t, "", res)
+	u7 := uuid.FromStringOrNil(res.(string))
+	u7ts, err := uuid.TimestampFromV7(u7)
+	require.NoError(t, err)
+	actual, err := u7ts.Time()
+	require.NoError(t, err)
+	assert.Equal(t, ts.Truncate(time.Millisecond), actual, "expected: %s, got: %s", ts, actual)
+}
+
 func TestNanoidFunction(t *testing.T) {
 	e, err := InitFunctionHelper("nanoid")
 	require.NoError(t, err)