fix(tx-builder): avoid extra requests in tx validator

src/tx/validator.ts

@@ -15,6 +15,7 @@ import { concatBuffers, isAccountNotFoundError, isKeyOfObject } from '../utils/o
 import { encode, Encoded, Encoding } from '../utils/encoder';
 import Node, { TransformNodeType } from '../Node';
 import { Account } from '../apis/node';
+import { genAggressiveCacheGetResponsesPolicy } from '../utils/autorest';
 
 export interface ValidatorResult {
   message: string;
@@ -68,16 +69,25 @@ const getSenderAddress = (
  * to make sure it can be posted it to the chain
  * @category transaction builder
  * @param transaction - Base64Check-encoded transaction
- * @param node - Node to validate transaction against
+ * @param nodeNotCached - Node to validate transaction against
  * @param parentTxTypes - Types of parent transactions
  * @returns Array with verification errors
  * @example const errors = await verifyTransaction(transaction, node)
  */
 export default async function verifyTransaction(
   transaction: Encoded.Transaction | Encoded.Poi,
-  node: Node,
+  nodeNotCached: Node,
   parentTxTypes: Tag[] = [],
 ): Promise<ValidatorResult[]> {
+  let node = nodeNotCached;
+  if (
+    !node.pipeline.getOrderedPolicies()
+      .some(({ name }) => name === 'aggressive-cache-get-responses')
+  ) {
+    node = new Node(nodeNotCached.$host, { ignoreVersion: true });
+    node.pipeline.addPolicy(genAggressiveCacheGetResponsesPolicy());
+  }
+
   const { tx, txType } = unpackTx<Tag.SignedTx>(transaction);
   const address = getSenderAddress(tx)
     ?? (txType === Tag.SignedTx ? getSenderAddress(tx.encodedTx.tx) : undefined);

src/utils/autorest.ts

@@ -31,7 +31,7 @@ export const genCombineGetRequestsPolicy = (): AdditionalPolicyConfig => {
 
   return {
     policy: {
-      name: 'combine-requests',
+      name: 'combine-get-requests',
       async sendRequest(request, next) {
         if (request.method !== 'GET') return next(request);
         const key = JSON.stringify([request.url, request.body]);
@@ -48,6 +48,21 @@ export const genCombineGetRequestsPolicy = (): AdditionalPolicyConfig => {
   };
 };
 
+export const genAggressiveCacheGetResponsesPolicy = (): PipelinePolicy => {
+  const getRequests = new Map<string, Promise<PipelineResponse>>();
+
+  return {
+    name: 'aggressive-cache-get-responses',
+    async sendRequest(request, next) {
+      if (request.method !== 'GET') return next(request);
+      const key = JSON.stringify([request.url, request.body]);
+      const response = getRequests.get(key) ?? next(request);
+      getRequests.set(key, response);
+      return response;
+    },
+  };
+};
+
 export const genErrorFormatterPolicy = (
   getMessage: (b: any) => string,
 ): AdditionalPolicyConfig => ({

test/integration/chain.ts

@@ -114,6 +114,21 @@ describe('Node Chain', () => {
     isConfirmed2.should.be.equal(true);
   });
 
+  it('doesn\'t make extra requests', async () => {
+    const httpSpy = spy(http, 'request');
+    await aeSdk.spend(100, publicKey, { waitMined: false, verify: false });
+    expect(httpSpy.args.length).to.be.equal(2); // nonce, post tx
+    httpSpy.resetHistory();
+
+    await aeSdk.spend(100, publicKey, { waitMined: false, verify: false });
+    expect(httpSpy.args.length).to.be.equal(2); // nonce, post tx
+    httpSpy.resetHistory();
+
+    await aeSdk.spend(100, publicKey, { waitMined: false });
+    expect(httpSpy.args.length).to.be.equal(5); // nonce, validator(acc, height, status), post tx
+    httpSpy.restore();
+  });
+
   const accounts = new Array(10).fill(undefined).map(() => MemoryAccount.generate());
   const transactions: Encoded.TxHash[] = [];