[#142] container: panic on missing container

Return more descriptive error message for a user.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

container/container_contract.go

@@ -61,6 +61,9 @@ const (
 	estimateKeyPrefix   = "cnr"
 	estimatePostfixSize = 10
 	cleanupDelta        = 3
+
+	// NotFoundError is returned if container is missing.
+	NotFoundError = "container does not exist"
 )
 
 var (
@@ -292,13 +295,15 @@ func checkNiceNameAvailable(nnsContractAddr interop.Hash160, domain string) bool
 // Signature is a RFC6979 signature of container ID.
 // Token is optional and should be stable marshaled SessionToken structure from
 // API.
+//
+// If a container doesn't exist it panics with NotFoundError.
 func Delete(containerID []byte, signature interop.Signature, token []byte) {
 	ctx := storage.GetContext()
 	notaryDisabled := storage.Get(ctx, notaryDisabledKey).(bool)
 
 	ownerID := getOwnerByID(ctx, containerID)
-	if len(ownerID) == 0 {
+	if ownerID == nil {
-		return
+		panic(NotFoundError)
 	}
 
 	if notaryDisabled {
@@ -345,15 +350,27 @@ func Delete(containerID []byte, signature interop.Signature, token []byte) {
 // Get method returns structure that contains stable marshaled Container structure,
 // signature, public key of the container creator and stable marshaled SessionToken
 // structure if it was provided.
+//
+// If a container doesn't exist it panics with NotFoundError.
 func Get(containerID []byte) Container {
 	ctx := storage.GetReadOnlyContext()
-	return getContainer(ctx, containerID)
+	cnt := getContainer(ctx, containerID)
+	if len(cnt.value) == 0 {
+		panic(NotFoundError)
+	}
+	return cnt
 }
 
 // Owner method returns 25 byte Owner ID of the container.
+//
+// If a container doesn't exist it panics with NotFoundError.
 func Owner(containerID []byte) []byte {
 	ctx := storage.GetReadOnlyContext()
-	return getOwnerByID(ctx, containerID)
+	owner := getOwnerByID(ctx, containerID)
+	if owner == nil {
+		panic(NotFoundError)
+	}
+	return owner
 }
 
 // List method returns list of all container IDs owned by specified owner.
@@ -384,6 +401,8 @@ func List(owner []byte) [][]byte {
 // PublicKey contains public key of the signer.
 // Token is optional and should be stable marshaled SessionToken structure from
 // API.
+//
+// If a container doesn't exist it panics with NotFoundError.
 func SetEACL(eACL []byte, signature interop.Signature, publicKey interop.PublicKey, token []byte) {
 	ctx := storage.GetContext()
 	notaryDisabled := storage.Get(ctx, notaryDisabledKey).(bool)
@@ -394,8 +413,8 @@ func SetEACL(eACL []byte, signature interop.Signature, publicKey interop.PublicK
 	containerID := eACL[offset : offset+32]
 
 	ownerID := getOwnerByID(ctx, containerID)
-	if len(ownerID) == 0 {
+	if ownerID == nil {
-		panic("container does not exist")
+		panic(NotFoundError)
 	}
 
 	if notaryDisabled {
@@ -439,12 +458,14 @@ func SetEACL(eACL []byte, signature interop.Signature, publicKey interop.PublicK
 // EACL method returns structure that contains stable marshaled EACLTable structure,
 // signature, public key of the extended ACL setter and stable marshaled SessionToken
 // structure if it was provided.
+//
+// If a container doesn't exist it panics with NotFoundError.
 func EACL(containerID []byte) ExtendedACL {
 	ctx := storage.GetReadOnlyContext()
 
 	ownerID := getOwnerByID(ctx, containerID)
-	if len(ownerID) == 0 {
+	if ownerID == nil {
-		panic("container does not exist")
+		panic(NotFoundError)
 	}
 
 	return getEACL(ctx, containerID)
@@ -453,9 +474,15 @@ func EACL(containerID []byte) ExtendedACL {
 // PutContainerSize method saves container size estimation in contract
 // memory. Can be invoked only by Storage nodes from the network map. Method
 // checks witness based on the provided public key of the Storage node.
+//
+// If a container doesn't exist it panics with NotFoundError.
 func PutContainerSize(epoch int, cid []byte, usedSize int, pubKey interop.PublicKey) {
 	ctx := storage.GetContext()
 
+	if getOwnerByID(ctx, cid) == nil {
+		panic(NotFoundError)
+	}
+
 	if !runtime.CheckWitness(pubKey) {
 		panic("invalid witness of container size estimation")
 	}

tests/container_test.go

@@ -2,6 +2,7 @@ package tests
 
 import (
 	"crypto/sha256"
+	"strings"
 	"testing"
 
 	"github.com/mr-tron/base58"
@@ -185,11 +186,62 @@ func TestContainerDelete(t *testing.T) {
 	AddBlockCheckHalt(t, bc, tx)
 
 	tx = PrepareInvoke(t, bc, acc, h, "get", c.id[:])
+	_, err := TestInvoke(bc, tx)
+	require.Error(t, err)
+	require.True(t, strings.Contains(err.Error(), container.NotFoundError))
+}
+
+func TestContainerOwner(t *testing.T) {
+	bc := NewChain(t)
+	h, balanceHash := prepareContainerContract(t, bc)
+
+	acc := NewAccount(t, bc)
+	balanceMint(t, bc, acc, balanceHash, containerFee*1, []byte{})
+
+	c := dummyContainer(acc)
+	tx := PrepareInvoke(t, bc, CommitteeAcc, h, "put", c.value, c.sig, c.pub, c.token)
+	AddBlockCheckHalt(t, bc, tx)
+
+	t.Run("missing container", func(t *testing.T) {
+		id := c.id
+		id[0] ^= 0xFF
+		tx = PrepareInvoke(t, bc, CommitteeAcc, h, "owner", id[:])
+		_, err := TestInvoke(bc, tx)
+		require.Error(t, err)
+		require.True(t, strings.Contains(err.Error(), container.NotFoundError))
+	})
+
+	tx = PrepareInvoke(t, bc, CommitteeAcc, h, "owner", c.id[:])
+	owner, _ := base58.Decode(acc.Address)
+	CheckTestInvoke(t, bc, tx, stackitem.NewBuffer(owner))
+}
+
+func TestContainerGet(t *testing.T) {
+	bc := NewChain(t)
+	h, balanceHash := prepareContainerContract(t, bc)
+
+	acc := NewAccount(t, bc)
+	balanceMint(t, bc, acc, balanceHash, containerFee*1, []byte{})
+
+	c := dummyContainer(acc)
+	tx := PrepareInvoke(t, bc, CommitteeAcc, h, "put", c.value, c.sig, c.pub, c.token)
+	AddBlockCheckHalt(t, bc, tx)
+
+	t.Run("missing container", func(t *testing.T) {
+		id := c.id
+		id[0] ^= 0xFF
+		tx = PrepareInvoke(t, bc, CommitteeAcc, h, "get", id[:])
+		_, err := TestInvoke(bc, tx)
+		require.Error(t, err)
+		require.True(t, strings.Contains(err.Error(), container.NotFoundError))
+	})
+
+	tx = PrepareInvoke(t, bc, CommitteeAcc, h, "get", c.id[:])
 	CheckTestInvoke(t, bc, tx, stackitem.NewStruct([]stackitem.Item{
-		stackitem.NewBuffer([]byte{}),
+		stackitem.NewByteArray(c.value),
-		stackitem.NewBuffer([]byte{}),
+		stackitem.NewByteArray(c.sig),
-		stackitem.NewBuffer([]byte{}),
+		stackitem.NewByteArray(c.pub),
-		stackitem.NewBuffer([]byte{}),
+		stackitem.NewByteArray(c.token),
 	}))
 }
 
@@ -222,6 +274,16 @@ func TestContainerSetEACL(t *testing.T) {
 	tx := PrepareInvoke(t, bc, CommitteeAcc, h, "put", c.value, c.sig, c.pub, c.token)
 	AddBlockCheckHalt(t, bc, tx)
 
+	t.Run("missing container", func(t *testing.T) {
+		id := c.id
+		id[0] ^= 0xFF
+		e := dummyEACL(id)
+		tx = PrepareInvoke(t, bc, CommitteeAcc, h, "setEACL", e.value, e.sig, e.pub, e.token)
+		_, err := TestInvoke(bc, tx)
+		require.Error(t, err)
+		require.True(t, strings.Contains(err.Error(), container.NotFoundError))
+	})
+
 	e := dummyEACL(c.id)
 	tx = PrepareInvoke(t, bc, acc, h, "setEACL", e.value, e.sig, e.pub, e.token)
 	AddBlock(t, bc, tx)