chore: add regression test for issue 823 (#867)

Fixed in #824

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>
Co-authored-by: Anton Medvedev <anton@medv.io>

Author: thevilledev

test/issues/823/issue_test.go

@@ -0,0 +1,39 @@
+package issue_test
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/expr-lang/expr"
+	"github.com/expr-lang/expr/internal/testify/require"
+)
+
+type env struct {
+	Ctx context.Context `expr:"ctx"`
+}
+
+func TestIssue823(t *testing.T) {
+	p, err := expr.Compile(
+		"now2().After(date2())",
+		expr.Env(env{}),
+		expr.WithContext("ctx"),
+		expr.Function(
+			"now2",
+			func(params ...any) (any, error) { return time.Now(), nil },
+			new(func(context.Context) time.Time),
+		),
+		expr.Function(
+			"date2",
+			func(params ...any) (any, error) { return time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC), nil },
+			new(func(context.Context) time.Time),
+		),
+	)
+	fmt.Printf("Compile result err: %v\n", err)
+	require.NoError(t, err)
+
+	r, err := expr.Run(p, &env{Ctx: context.Background()})
+	require.NoError(t, err)
+	require.True(t, r.(bool))
+}