[#905] Make morph client non-panic-prone

Morph client returns errors instead.

Signed-off-by: Ekaterina Lebedeva <ekaterina.lebedeva@yadro.com>

pkg/morph/client/constructor.go

@@ -74,8 +74,6 @@ func defaultConfig() *cfg {
 // Notary support should be enabled with EnableNotarySupport client
 // method separately.
 //
-// If private key is nil, it panics.
-//
 // Other values are set according to provided options, or by default:
 //   - client context: Background;
 //   - dial timeout: 5s;
@@ -92,7 +90,7 @@ func defaultConfig() *cfg {
 // If there are no healthy endpoint - returns ErrNoHealthyEndpoint.
 func New(ctx context.Context, key *keys.PrivateKey, opts ...Option) (*Client, error) {
 	if key == nil {
-		panic("empty private key")
+		return nil, errors.New("empty private key")
 	}
 
 	acc := wallet.NewAccountFromPrivateKey(key)

pkg/morph/client/notary.go

@@ -61,8 +61,8 @@ const (
 	notaryExpirationOfMethod = "expirationOf"
 	setDesignateMethod       = "designateAsRole"
 
-	notaryBalanceErrMsg      = "can't fetch notary balance"
-	notaryNotEnabledPanicMsg = "notary support was not enabled on this client"
+	notaryBalanceErrMsg    = "can't fetch notary balance"
+	notaryNotEnabledErrMsg = "notary support was not enabled on this client"
 )
 
 var errUnexpectedItems = errors.New("invalid number of NEO VM arguments on stack")
@@ -190,7 +190,7 @@ func (c *Client) ProbeNotary() (res bool) {
 // be called periodically. Notary support should be enabled in client to
 // use this function.
 //
-// This function must be invoked with notary enabled otherwise it throws panic.
+// This function must be invoked with notary enabled.
 func (c *Client) DepositNotary(amount fixedn.Fixed8, delta uint32) (res util.Uint256, err error) {
 	c.switchLock.RLock()
 	defer c.switchLock.RUnlock()
@@ -200,7 +200,7 @@ func (c *Client) DepositNotary(amount fixedn.Fixed8, delta uint32) (res util.Uin
 	}
 
 	if c.notary == nil {
-		panic(notaryNotEnabledPanicMsg)
+		return util.Uint256{}, fmt.Errorf(notaryNotEnabledErrMsg)
 	}
 
 	bc, err := c.rpcActor.GetBlockCount()
@@ -225,7 +225,7 @@ func (c *Client) DepositNotary(amount fixedn.Fixed8, delta uint32) (res util.Uin
 // this method sets notary deposit till parameter to a maximum possible value.
 // This allows to avoid ValidAfterDeposit failures.
 //
-// This function must be invoked with notary enabled otherwise it throws panic.
+// This function must be invoked with notary enabled.
 func (c *Client) DepositEndlessNotary(amount fixedn.Fixed8) (res util.Uint256, err error) {
 	c.switchLock.RLock()
 	defer c.switchLock.RUnlock()
@@ -235,7 +235,7 @@ func (c *Client) DepositEndlessNotary(amount fixedn.Fixed8) (res util.Uint256, e
 	}
 
 	if c.notary == nil {
-		panic(notaryNotEnabledPanicMsg)
+		return util.Uint256{}, errors.New(notaryNotEnabledErrMsg)
 	}
 
 	// till value refers to a block height and it is uint32 value in neo-go
@@ -275,7 +275,7 @@ func (c *Client) depositNotary(amount fixedn.Fixed8, till int64) (res util.Uint2
 // GetNotaryDeposit returns deposit of client's account in notary contract.
 // Notary support should be enabled in client to use this function.
 //
-// This function must be invoked with notary enabled otherwise it throws panic.
+// This function must be invoked with notary enabled.
 func (c *Client) GetNotaryDeposit() (res int64, err error) {
 	c.switchLock.RLock()
 	defer c.switchLock.RUnlock()
@@ -285,7 +285,7 @@ func (c *Client) GetNotaryDeposit() (res int64, err error) {
 	}
 
 	if c.notary == nil {
-		panic(notaryNotEnabledPanicMsg)
+		return 0, errors.New(notaryNotEnabledErrMsg)
 	}
 
 	sh := c.acc.PrivateKey().PublicKey().GetScriptHash()
@@ -327,7 +327,7 @@ func (u *UpdateNotaryListPrm) SetHash(hash util.Uint256) {
 // UpdateNotaryList updates list of notary nodes in designate contract. Requires
 // committee multi signature.
 //
-// This function must be invoked with notary enabled otherwise it throws panic.
+// This function must be invoked with notary enabled.
 func (c *Client) UpdateNotaryList(prm UpdateNotaryListPrm) error {
 	c.switchLock.RLock()
 	defer c.switchLock.RUnlock()
@@ -337,7 +337,7 @@ func (c *Client) UpdateNotaryList(prm UpdateNotaryListPrm) error {
 	}
 
 	if c.notary == nil {
-		panic(notaryNotEnabledPanicMsg)
+		return errors.New(notaryNotEnabledErrMsg)
 	}
 
 	nonce, vub, err := c.CalculateNonceAndVUB(&prm.hash)
@@ -375,7 +375,7 @@ func (u *UpdateAlphabetListPrm) SetHash(hash util.Uint256) {
 // As for sidechain list should contain all inner ring nodes.
 // Requires committee multi signature.
 //
-// This function must be invoked with notary enabled otherwise it throws panic.
+// This function must be invoked with notary enabled.
 func (c *Client) UpdateNeoFSAlphabetList(prm UpdateAlphabetListPrm) error {
 	c.switchLock.RLock()
 	defer c.switchLock.RUnlock()
@@ -385,7 +385,7 @@ func (c *Client) UpdateNeoFSAlphabetList(prm UpdateAlphabetListPrm) error {
 	}
 
 	if c.notary == nil {
-		panic(notaryNotEnabledPanicMsg)
+		return errors.New(notaryNotEnabledErrMsg)
 	}
 
 	nonce, vub, err := c.CalculateNonceAndVUB(&prm.hash)

pkg/morph/client/notifications.go

@@ -63,7 +63,7 @@ func (c *Client) ReceiveBlocks(ch chan<- *block.Block) (string, error) {
 // connection to any of passed RPC endpoints.
 func (c *Client) ReceiveNotaryRequests(txSigner util.Uint160, ch chan<- *result.NotaryRequestEvent) (string, error) {
 	if c.notary == nil {
-		panic(notaryNotEnabledPanicMsg)
+		panic(notaryNotEnabledErrMsg)
 	}
 
 	c.switchLock.Lock()