fix: add getBlocksSince Connection method

web3.js/src/connection.js

@@ -365,6 +365,11 @@ const GetTotalSupplyRpcResult = jsonRpcResult('number');
  */
 const GetMinimumBalanceForRentExemptionRpcResult = jsonRpcResult('number');
 
+/**
+ * Expected JSON RPC response for the "getBlocksSince" message
+ */
+const GetBlocksSinceRpcResult = jsonRpcResult(struct.list(['number']));
+
 /**
  * Expected JSON RPC response for the "getRecentBlockhash" message
  */
@@ -853,6 +858,19 @@ export class Connection {
     return res.result;
   }
 
+  /**
+   * Fetch a list of rooted blocks from the cluster
+   */
+  async getBlocksSince(slot: number): Promise<Array<number>> {
+    const unsafeRes = await this._rpcRequest('getBlocksSince', [slot]);
+    const res = GetBlocksSinceRpcResult(unsafeRes);
+    if (res.error) {
+      throw new Error(res.error.message);
+    }
+    assert(typeof res.result !== 'undefined');
+    return res.result;
+  }
+
   /**
    * Request an allocation of lamports to the specified account
    */

web3.js/src/transaction.js

@@ -445,7 +445,7 @@ export class Transaction {
     const PUBKEY_LENGTH = 32;
     const SIGNATURE_LENGTH = 64;
 
-    function isCreditDebit(
+    function isWritable(
       i: number,
       numRequiredSignatures: number,
       numReadonlySignedAccounts: number,
@@ -530,7 +530,7 @@ export class Transaction {
           isSigner: transaction.signatures.some(
             keyObj => keyObj.publicKey.toString() === pubkey.toString(),
           ),
-          isWritable: isCreditDebit(
+          isWritable: isWritable(
             j,
             numRequiredSignatures,
             numReadonlySignedAccounts,