add refund integration test

examples/morpheusvm/tests/transfer.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/ava-labs/hypersdk/api/indexer"
 	"github.com/ava-labs/hypersdk/auth"
 	"github.com/ava-labs/hypersdk/chain"
 	"github.com/ava-labs/hypersdk/crypto/ed25519"
@@ -44,3 +45,56 @@ var _ = registry.Register(TestsRegistry, "Transfer Transaction", func(t ginkgo.F
 
 	require.NoError(tn.ConfirmTxs(timeoutCtx, []*chain.Transaction{tx}))
 })
+
+var _ = registry.Register(TestsRegistry, "Read From Memory Refund", func(t ginkgo.FullGinkgoTInterface, tn tworkload.TestNetwork) {
+	require := require.New(t)
+	other, err := ed25519.GeneratePrivateKey()
+	require.NoError(err)
+	toAddress := auth.NewED25519Address(other.PublicKey())
+
+	// We first warm up the state we want to test
+	authFactory := tn.Configuration().AuthFactories()[0]
+	tx, err := tn.GenerateTx(context.Background(), []chain.Action{&actions.Transfer{
+		To:    toAddress,
+		Value: 1,
+		Memo:  []byte("warming up keys"),
+	}},
+		authFactory,
+	)
+	require.NoError(err)
+
+	timeoutCtx, timeoutCtxFnc := context.WithDeadline(context.Background(), time.Now().Add(30*time.Second))
+	defer timeoutCtxFnc()
+
+	// This call implicitly enforces that the state is warmed up by having the
+	// VM produce + accept a new block
+	require.NoError(tn.ConfirmTxs(timeoutCtx, []*chain.Transaction{tx}))
+
+	indexerCli := indexer.NewClient(tn.URIs()[0])
+	resp, success, err := indexerCli.GetTx(timeoutCtx, tx.GetID())
+	require.True(success)
+	require.NoError(err)
+	coldFee := resp.Fee
+
+	// If TX successful, state is now warmed up
+	// Now we can test the refund
+	tx, err = tn.GenerateTx(context.Background(), []chain.Action{&actions.Transfer{
+		To:    toAddress,
+		Value: 1,
+		Memo:  []byte("testing refunds"),
+	}},
+		authFactory,
+	)
+	require.NoError(err)
+
+	require.NoError(tn.ConfirmTxs(timeoutCtx, []*chain.Transaction{tx}))
+
+	queryCtx, queryCtxFnc := context.WithDeadline(context.Background(), time.Now().Add(30*time.Second))
+	defer queryCtxFnc()
+
+	resp, success, err = indexerCli.GetTx(queryCtx, tx.GetID())
+	require.NoError(err)
+	require.True(success)
+
+	require.Less(resp.Fee, coldFee)
+})