feat: Ability to get withdrawal fee estimate

src/withdraw/WithdrawAPI.test.ts

@@ -1,7 +1,10 @@
 import nock from 'nock';
-import {WithdrawAPI, CryptoWithdrawal} from './WithdrawAPI';
+import {WithdrawAPI, CryptoWithdrawal, WithdrawalFeeEstimate} from './WithdrawAPI';
 
 describe('WithdrawAPI', () => {
+  const currency = 'BTC';
+  const cryptoAddress = '1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa';
+  const expectedFeeEstimate: WithdrawalFeeEstimate = {fee: '.01'};
   const withdrawalId = 'fake-withdrawal-id-abcd-01234';
 
   afterAll(() => nock.cleanAll());
@@ -18,13 +21,14 @@ describe('WithdrawAPI', () => {
           id: withdrawalId,
         };
         return [200, JSON.stringify(response)];
-      });
+      })
+      .get(WithdrawAPI.URL.WITHDRAWALS.FEE_ESTIMATE)
+      .query({crypto_address: cryptoAddress, currency})
+      .reply(200, JSON.stringify(expectedFeeEstimate));
   });
 
   describe('postCryptoWithdrawal', () => {
     const amount = 1.23;
-    const currency = 'BTC';
-    const cryptoAddress = '1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa';
     const destinationTag = 'satoshi-nakamoto';
 
     it('creates a new withdrawal to crypto address', async () => {
@@ -42,4 +46,11 @@ describe('WithdrawAPI', () => {
       expect(withdrawal).toEqual({amount, currency, id: withdrawalId});
     });
   });
+
+  describe('getFeeEstimate', () => {
+    it('gets a fee estimate', async () => {
+      const estimate = await global.client.rest.withdraw.getFeeEstimate(currency, cryptoAddress);
+      expect(estimate).toEqual(expectedFeeEstimate);
+    });
+  });
 });

src/withdraw/WithdrawAPI.ts

@@ -15,10 +15,15 @@ interface CryptoWithdrawalRequest {
   no_destination_tag?: boolean;
 }
 
+export interface WithdrawalFeeEstimate {
+  fee: string;
+}
+
 export class WithdrawAPI {
   static readonly URL = {
     WITHDRAWALS: {
       CRYPTO: '/withdrawals/crypto',
+      FEE_ESTIMATE: '/withdrawals/fee-estimate',
     },
   };
 
@@ -57,4 +62,19 @@ export class WithdrawAPI {
     const response = await this.apiClient.post(resource, withdrawal);
     return response.data;
   }
+
+  /**
+   * Gets the network fee estimate when sending to the given address.
+   *
+   * @param currency - The type of currency
+   * @param cryptoAddress - A crypto address of the recipient
+   * @see https://docs.pro.coinbase.com/#fee-estimate
+   */
+  async getFeeEstimate(currency: string, cryptoAddress: string): Promise<WithdrawalFeeEstimate> {
+    const resource = WithdrawAPI.URL.WITHDRAWALS.FEE_ESTIMATE;
+    const response = await this.apiClient.get<WithdrawalFeeEstimate>(resource, {
+      params: {crypto_address: cryptoAddress, currency},
+    });
+    return response.data;
+  }
 }