feat: skip timestamp in test

feat: add test.gno

feat: TestSkipTimestamps now takes time.Duration

feat: use time instead of std.GetTimestamp

examples/gno.land/r/demo/mtimestamp/mtimestamp.gno

@@ -0,0 +1 @@
+package mtimestamp

examples/gno.land/r/demo/mtimestamp/mtimestamp_test.gno

@@ -0,0 +1,23 @@
+package mtimestamp
+
+import (
+	"time"
+	"std"
+	"testing"
+)
+
+
+func TestSkipDuration(t *testing.T) {
+	// Duration 3hr 2min 1sec
+	myDur := time.Second * 1
+	myDur += time.Minute * 2
+	myDur += time.Hour * 3
+
+	start := time.Now()
+	std.TestSkipTimestamps(myDur)
+	end := time.Now()
+
+	if end.Sub(start) != myDur {
+		t.Errorf("time diff between start and end should be equal to myDur %v), but got %v", myDur, end.Sub(start))
+	}
+}

gnovm/tests/imports.go

@@ -636,6 +636,29 @@ func testPackageInjector(store gno.Store, pn *gno.PackageNode) {
 				m.Context = ctx
 			},
 		)
+		pn.DefineNative("TestSkipTimestamps",
+			gno.Flds( // params
+				"timestamp", gno.AnyT(), // NOTE: should be time.Duration
+			),
+			gno.Flds( // results
+			),
+			func(m *gno.Machine) {
+				arg0 := m.LastBlock().GetParams1().TV
+
+				d := arg0.GetInt64()
+				sec := d / int64(time.Second)
+				nano := d % int64(time.Second)
+
+				ctx := m.Context.(stdlibs.ExecContext)
+				ctx.Timestamp += sec
+				ctx.TimestampNano += nano
+				if ctx.TimestampNano >= int64(time.Second) {
+					ctx.Timestamp += 1
+					ctx.TimestampNano -= int64(time.Second)
+				}
+				m.Context = ctx
+			},
+		)
 		// TODO: move elsewhere.
 		pn.DefineNative("ClearStoreCache",
 			gno.Flds( // params