feat(jellyfish-api-core): add blockchain getMempoolDescendants RPC (#…

…1796)

What this PR does / why we need it:
/kind feature

Which issue(s) does this PR fixes?:
Fixes part of #48

- Implements `getmempooldescendants` type for RPC.

docs/node/CATEGORIES/01-blockchain.md

@@ -334,6 +334,49 @@ interface MempoolTx {
 }
 ```
 
+## getMempoolDescendants
+
+Get all in-mempool descendants if a transaction id is in mempool as string[] if verbose is false else as json object
+
+```ts title="client.blockchain.getMempoolDescendants()"
+interface blockchain {
+  getMempoolDescendants (txId: string, verbose?: false): Promise<string[]>
+  getMempoolDescendants (txId: string, verbose?: true): Promise<MempoolTx>
+  getMempoolDescendants (txId: string, verbose?: boolean: Promise<string[] | MempoolTx>
+}
+
+interface MempoolTx {
+  [key: string]: {
+    vsize: BigNumber
+    /**
+     * @deprecated same as vsize. Only returned if defid is started with -deprecatedrpc=size
+     */
+    size: BigNumber
+    weight: BigNumber
+    fee: BigNumber
+    modifiedfee: BigNumber
+    time: BigNumber
+    height: BigNumber
+    descendantcount: BigNumber
+    descendantsize: BigNumber
+    descendantfees: BigNumber
+    ancestorcount: BigNumber
+    ancestorsize: BigNumber
+    ancestorfees: BigNumber
+    wtxid: string
+    fees: {
+      base: BigNumber
+      modified: BigNumber
+      ancestor: BigNumber
+      descendant: BigNumber
+    }
+    depends: string[]
+    spentby: string[]
+    'bip125-replaceable': boolean
+  }
+}
+```
+
 ## getMempoolEntry
 
 Get transaction details in the memory pool using a transaction ID.

packages/jellyfish-api-core/__tests__/category/blockchain/getMempoolDescendants.test.ts

@@ -0,0 +1,111 @@
+import { MasterNodeRegTestContainer } from '@defichain/testcontainers'
+import { Testing } from '@defichain/jellyfish-testing'
+import BigNumber from 'bignumber.js'
+
+describe('Transactions without descendants', () => {
+  const container = new MasterNodeRegTestContainer()
+  const testing = Testing.create(container)
+
+  beforeAll(async () => {
+    await testing.container.start()
+    await testing.container.waitForWalletCoinbaseMaturity()
+  })
+
+  afterAll(async () => {
+    await testing.container.stop()
+  })
+
+  it('should return empty array for transaction id without descendants', async () => {
+    const txId = await testing.rpc.wallet.sendToAddress('mwsZw8nF7pKxWH8eoKL9tPxTpaFkz7QeLU', 0.003)
+    const mempoolDescendants = await testing.rpc.blockchain.getMempoolDescendants(txId)
+
+    expect(mempoolDescendants.length).toStrictEqual(0)
+  })
+
+  it('should return error if transaction is not in mempool', async () => {
+    const nonExistingTxId = 'a'.repeat(64)
+    const promise = testing.rpc.blockchain.getMempoolDescendants(nonExistingTxId)
+
+    await expect(promise)
+      .rejects
+      .toThrowError('RpcApiError: \'Transaction not in mempool\', code: -5, method: getmempooldescendants')
+  })
+
+  it('should return error if transaction id has an invalid length', async () => {
+    const invalidLengthTxid = 'a'.repeat(5)
+    const promise = testing.rpc.blockchain.getMempoolDescendants(invalidLengthTxid)
+
+    await expect(promise)
+      .rejects
+      .toThrow(`RpcApiError: 'parameter 1 must be of length 64 (not ${invalidLengthTxid.length}, for '${invalidLengthTxid}')', code: -8, method: getmempooldescendants`)
+  })
+})
+
+describe('Transactions with descendants', () => {
+  const container = new MasterNodeRegTestContainer()
+  const testing = Testing.create(container)
+
+  beforeAll(async () => {
+    await testing.container.start()
+    await testing.container.waitForWalletCoinbaseMaturity()
+  })
+
+  async function getTxIdWithDescendants (): Promise<string> {
+    const txId = await testing.rpc.wallet.sendToAddress('mwsZw8nF7pKxWH8eoKL9tPxTpaFkz7QeLU', 0.003)
+    for (let i = 0; i < 10; i++) {
+      await testing.rpc.wallet.sendToAddress('mwsZw8nF7pKxWH8eoKL9tPxTpaFkz7QeLU', 0.003)
+    }
+    return txId
+  }
+
+  afterAll(async () => {
+    await testing.container.stop()
+  })
+
+  it('should return JSON object if verbose is true', async () => {
+    const txIdWithDescendants = await getTxIdWithDescendants()
+    const mempoolDescendants = await testing.rpc.blockchain.getMempoolDescendants(txIdWithDescendants, true)
+
+    const keys = Object.keys(mempoolDescendants)
+    expect(keys.length).toBeGreaterThan(0)
+    for (const key of keys) {
+      expect(mempoolDescendants[key]).toStrictEqual({
+        fees: expect.any(Object),
+        vsize: expect.any(BigNumber),
+        weight: expect.any(BigNumber),
+        fee: expect.any(BigNumber),
+        modifiedfee: expect.any(BigNumber),
+        time: expect.any(BigNumber),
+        height: expect.any(BigNumber),
+        descendantcount: expect.any(BigNumber),
+        descendantsize: expect.any(BigNumber),
+        descendantfees: expect.any(BigNumber),
+        ancestorcount: expect.any(BigNumber),
+        ancestorsize: expect.any(BigNumber),
+        ancestorfees: expect.any(BigNumber),
+        wtxid: expect.any(String),
+        depends: expect.any(Array),
+        spentby: expect.any(Array),
+        'bip125-replaceable': expect.any(Boolean)
+      })
+    }
+  })
+
+  it('should return array of transaction ids if verbose is false', async () => {
+    const txIdWithDescendants = await getTxIdWithDescendants()
+    const mempoolDescendants = await testing.rpc.blockchain.getMempoolDescendants(txIdWithDescendants, false)
+    expect(mempoolDescendants.length).toBeGreaterThan(0)
+    for (const descendantId of mempoolDescendants) {
+      expect(descendantId).toStrictEqual(expect.stringMatching(/^[0-9a-f]{64}$/))
+    }
+  })
+
+  it('should return array of transaction ids if verbose is undefined', async () => {
+    const txIdWithDescendants = await getTxIdWithDescendants()
+    const mempoolDescendants = await testing.rpc.blockchain.getMempoolDescendants(txIdWithDescendants)
+    expect(mempoolDescendants.length).toBeGreaterThan(0)
+    for (const descendantId of mempoolDescendants) {
+      expect(descendantId).toStrictEqual(expect.stringMatching(/^[0-9a-f]{64}$/))
+    }
+  })
+})

packages/jellyfish-api-core/src/category/blockchain.ts

@@ -206,6 +206,36 @@ export class Blockchain {
     return await this.client.call('getmempoolancestors', [txId, verbose], 'bignumber')
   }
 
+  /**
+  * Get all in-mempool descendants for a given transaction as string[]
+  *
+  * @param {string} txId the transaction id
+  * @param {boolean} verbose false
+  * @return {Promise<string[]>}
+  */
+  getMempoolDescendants (txId: string, verbose?: false): Promise<string[]>
+
+  /**
+  * Get all in-mempool descendants for a given transaction as json object
+  *
+  * @param {string} txId the transaction id
+  * @param {boolean} verbose true
+  * @return {Promise<MempoolTx>}
+  */
+  getMempoolDescendants (txId: string, verbose?: true): Promise<MempoolTx>
+
+  /**
+   * Get all in-mempool descendants if txId is in mempool as string[] if verbose is false
+   * else as json object
+   *
+   * @param {string} txId the transaction id
+   * @param {boolean} verbose default = false, true for json object, false for array of transaction ids
+   * @return {Promise<string[] | MempoolTx>}
+   */
+  async getMempoolDescendants (txId: string, verbose: boolean = false): Promise<string[] | MempoolTx> {
+    return await this.client.call('getmempooldescendants', [txId, verbose], 'bignumber')
+  }
+
   /**
    * Get mempool data for the given transaction
    * @param {string} txId the transaction id