feat: add TO_DURATION function with string parsing and validation, update related tests

Author: ziflex

pkg/stdlib/types/lib.go

@@ -9,6 +9,7 @@ func RegisterLib(ns runtime.Namespace) {
 		Add("TO_BOOL", ToBool).
 		Add("TO_INT", ToInt).
 		Add("TO_FLOAT", ToFloat).
+		Add("TO_DURATION", ToDuration).
 		Add("TO_STRING", ToString).
 		Add("TO_DATETIME", ToDateTime).
 		Add("TO_ARRAY", ToArray).

pkg/stdlib/types/to_duration.go

@@ -0,0 +1,22 @@
+package types
+
+import (
+	"context"
+
+	"github.com/MontFerret/ferret/v2/pkg/runtime"
+)
+
+// ToDuration returns a native duration or parses one from its string representation.
+// Numeric values are not interpreted as durations.
+// @param {Duration|String} value - A native duration or duration string.
+// @return {Duration} - A native duration value.
+func ToDuration(_ context.Context, arg runtime.Value) (runtime.Value, error) {
+	switch value := arg.(type) {
+	case runtime.Duration:
+		return value, nil
+	case runtime.String:
+		return runtime.ParseDuration(value.String())
+	default:
+		return runtime.None, runtime.TypeErrorOf(arg, runtime.TypeDuration, runtime.TypeString)
+	}
+}

pkg/stdlib/types/to_duration_test.go

@@ -0,0 +1,72 @@
+package types
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/MontFerret/ferret/v2/pkg/runtime"
+)
+
+func TestToDuration(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		input    runtime.Value
+		name     string
+		expected runtime.Duration
+	}{
+		{
+			name:     "duration",
+			input:    runtime.NewDuration(250 * time.Millisecond),
+			expected: runtime.NewDuration(250 * time.Millisecond),
+		},
+		{
+			name:     "literal string",
+			input:    runtime.NewString("1.5s"),
+			expected: runtime.NewDuration(1500 * time.Millisecond),
+		},
+		{
+			name:     "normalized string",
+			input:    runtime.NewString("1h30m"),
+			expected: runtime.NewDuration(90 * time.Minute),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			actual, err := ToDuration(t.Context(), tt.input)
+			if err != nil {
+				t.Fatalf("ToDuration() error = %v", err)
+			}
+
+			duration, err := runtime.CastDuration(actual)
+			if err != nil {
+				t.Fatalf("ToDuration() result type = %s, want Duration", runtime.TypeOf(actual))
+			}
+
+			if duration != tt.expected {
+				t.Fatalf("ToDuration() = %s, want %s", duration, tt.expected)
+			}
+		})
+	}
+}
+
+func TestToDurationRejectsUnsupportedType(t *testing.T) {
+	t.Parallel()
+
+	_, err := ToDuration(t.Context(), runtime.NewInt(1))
+	if !errors.Is(err, runtime.ErrInvalidType) {
+		t.Fatalf("ToDuration() error = %v, want invalid type", err)
+	}
+}
+
+func TestToDurationRejectsInvalidString(t *testing.T) {
+	t.Parallel()
+
+	if _, err := ToDuration(t.Context(), runtime.NewString("1fortnight")); err == nil {
+		t.Fatal("ToDuration() accepted an invalid duration string")
+	}
+}

test/integration/vm/vm_duration_test.go

@@ -28,6 +28,11 @@ func TestNativeDurationValues(t *testing.T) {
 		S(`RETURN 5s > 4999ms`, true),
 		S(`RETURN TYPENAME(5s)`, "Duration"),
 		S(`RETURN IS_DURATION(5s)`, true),
+		S(`RETURN TO_DURATION(5s)`, "5s"),
+		S(`RETURN TO_DURATION("250ms")`, "250ms"),
+		S(`RETURN TO_DURATION("1h30m")`, "1h30m0s"),
+		S(`RETURN TYPENAME(TO_DURATION("500ms"))`, "Duration"),
+		S(`RETURN TO_DURATION("500ms") + 500ms`, "1s"),
 		S(`RETURN MATCH 5s (5000ms => true, _ => false)`, true),
 		S(`RETURN DISTINCT [5s, 5000ms]`, []any{"5s"}),
 		spec.NewSpec(`RETURN 1s + 1`).Expect().ExecError(ShouldBeRuntimeError, &ExpectedRuntimeError{
@@ -39,6 +44,8 @@ func TestNativeDurationValues(t *testing.T) {
 		S(`RETURN 0.000001ms / 2`, "1ns"),
 		S(`RETURN (-0.000001ms) / 2`, "-1ns"),
 		Error(`RETURN 1s - 1`),
+		Error(`RETURN TO_DURATION(5000)`),
+		Error(`RETURN TO_DURATION("1fortnight")`),
 		Error(`RETURN 1s + "1s"`),
 		Error(`RETURN "1s" + 1s`),
 		Error("RETURN `${1s}`"),