[#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

@@ -76,8 +76,6 @@ 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;
@@ -94,7 +92,7 @@ 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

@@ -161,7 +161,7 @@ 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()
@@ -196,7 +196,7 @@ 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()
@@ -246,7 +246,7 @@ 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()
@@ -298,7 +298,7 @@ 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()
@@ -346,7 +346,7 @@ 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()

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(notaryDisabledErrMsg)
+		return "", ErrNotaryDisabled
 	}
 
 	c.switchLock.Lock()