fix(walletconnect): handle all possible response types from algo_sign…

…Txn (#185)

There are no restrictions or rules about the `algo_signTxn` RPC method response type. Each wallet can decide on its own how to format the signed transactions it returns.

(This should probably be spec'd or defined somewhere!)

The WalletConnect provider now handles numerous potential response types, to make sure it always returns an array of encoded signed transactions as `Promise<Uint8Array[]>`.

Its signing function response is now typed as

```ts
type SignTxnsResponse = Array<Uint8Array | string | null | undefined>
```

packages/use-wallet/src/__tests__/wallets/walletconnect.test.ts

@@ -521,6 +521,24 @@ describe('WalletConnect', () => {
           ])
         )
       })
+
+      it('should return encoded signed transactions if the wallet returns base64 strings', async () => {
+        const signedTxn = byteArrayToBase64(txn1.toByte())
+        mockSignClient.request.mockResolvedValueOnce([signedTxn])
+
+        const result = await wallet.signTransactions([txn1])
+
+        expect(result).toEqual([txn1.toByte()])
+      })
+
+      it('should return encoded signed transactions if the wallet returns Uint8Arrays', async () => {
+        const signedTxn = txn1.toByte()
+        mockSignClient.request.mockResolvedValueOnce([signedTxn])
+
+        const result = await wallet.signTransactions([txn1])
+
+        expect(result).toEqual([txn1.toByte()])
+      })
     })
 
     describe('transactionSigner', () => {

packages/use-wallet/src/wallets/walletconnect.ts

@@ -40,6 +40,8 @@ type WalletConnectModalOptions = Pick<
 
 export type WalletConnectOptions = SignClientOptions & WalletConnectModalOptions
 
+export type SignTxnsResponse = Array<Uint8Array | string | null | undefined>
+
 export class SessionError extends Error {
   constructor(message: string) {
     super(message)
@@ -352,16 +354,16 @@ export class WalletConnect extends BaseWallet {
       const request = formatJsonRpcRequest('algo_signTxn', [txnsToSign])
 
       // Sign transactions
-      const signTxnsResult = await client.request<Array<string | null>>({
+      const signTxnsResult = await client.request<SignTxnsResponse>({
         chainId: caipChainId[this.activeNetwork]!,
         topic: this.session.topic,
         request
       })
 
-      // Filter out null values
+      // Filter out nullish values
       const signedTxns = signTxnsResult.reduce<Uint8Array[]>((acc, value) => {
-        if (value !== null) {
-          const signedTxn = base64ToByteArray(value)
+        if (value) {
+          const signedTxn = typeof value === 'string' ? base64ToByteArray(value) : value
           acc.push(signedTxn)
         }
         return acc