Add isBlockhashValid method to web3.js

web3.js/src/connection.ts

@@ -937,6 +937,16 @@ const BlockProductionResponseStruct = jsonRpcResultAndContext(
   }),
 );
 
+/**
+ * Configuration object for changing `isBlockhashValid` query behavior
+ */
+export type IsBlockhashValidConfig = {
+  /** The level of commitment desired */
+  commitment?: Commitment;
+  /** The minimum slot that the request can be evaluated at */
+  minContextSlot?: number;
+}
+
 /**
  * A performance sample
  */
@@ -3359,6 +3369,35 @@ export class Connection {
     return res.result;
   }
 
+  /**
+   * Check whether a blockhash is still valid or not
+   */
+  async isBlockhashValid(
+    blockhash: string,
+    config?: IsBlockhashValidConfig
+  ): Promise<RpcResponseAndContext<boolean>> {
+    const extra: Pick<IsBlockhashValidConfig, 'minContextSlot'> = {};
+
+    const commitment = config
+      ? config.commitment
+      : this._commitment || 'finalized';
+    const args = this._buildArgs(
+      [blockhash],
+      commitment,
+      'jsonParsed',
+      extra,
+    );
+
+    const unsafeRes = await this._rpcRequest('isBlockhashValid', args);
+    const res = create(unsafeRes, jsonRpcResultAndContext(boolean()));
+    if ('error' in res) {
+      throw new Error(
+        'Could not determine if blockhash ' + blockhash + ' was valid: ' + res.error.message,
+      );
+    }
+    return res.result;
+  }
+
   /**
    * Fetch the node version
    */

web3.js/test/connection.test.ts

@@ -2952,6 +2952,61 @@ describe('Connection', function () {
     }
   });
 
+  describe('is blockhash valid', () => {
+    it('is blockhash valid - blockhash only (mock)', async () => {
+      const {blockhash} = await helpers.recentBlockhash({connection});
+
+      await mockRpcResponse({
+        method: 'isBlockhashValid',
+        params: [blockhash],
+        value: true,
+        withContext: true
+      });
+
+      const isValid = await connection.isBlockhashValid(blockhash);
+      expect(isValid.value).to.be.true;
+    });
+
+    it('is blockhash valid - blockhash and min slot (mock)', async () => {
+      const {blockhash} = await helpers.recentBlockhash({connection});
+
+      await mockRpcResponse({
+        method: 'isBlockhashValid',
+        params: [blockhash, {minContextSlot: 2}],
+        value: true,
+        withContext: true
+      });
+
+      const isValid = await connection.isBlockhashValid(blockhash, {minContextSlot: 2});
+      expect(isValid.value).to.be.true;
+    });
+
+    if (process.env.TEST_LIVE) {
+      it('is blockhash valid - blockhash only (live)', async () => {
+        const {blockhash} = await helpers.recentBlockhash({connection});
+        const isValid = await connection.isBlockhashValid(blockhash);
+        expect(isValid.value).to.be.true;
+      });
+
+      it('is blockhash valid - blockhash only and mint slot (live)', async () => {
+        const blockhash = await connection.getLatestBlockhashAndContext('finalized');
+
+        const isValid = await connection.isBlockhashValid(
+          blockhash.value.blockhash,
+          {
+            commitment: 'finalized',
+            minContextSlot: Number.MAX_SAFE_INTEGER
+          });
+        expect(isValid.value).to.be.false;
+      });
+
+      it('is blockhash valid - junk blockhash (live)', async () => {
+        const isValid = await connection.isBlockhashValid('57zQNBZBEiHsCZFqsaY6h176ioXy5MsSLmcvHkEyaLGy');
+        expect(isValid.value).to.be.false;
+      });
+    }
+  });
+
   it('get minimum ledger slot', async () => {
     await mockRpcResponse({
       method: 'minimumLedgerSlot',