- Remove bad guard clause on pagination handling (#419)

- Add unit test to verify pagination workflow retrieves all valid pages

src/services/base_service.js

@@ -216,7 +216,7 @@ export default (easypostClient) =>
       };
 
       const response = await this._all(url, params);
-      if (response == undefined || response[url].length == 0 || !response.has_more) {
+      if (response == undefined || response[url].length == 0) {
         throw new EndOfPaginationError();
       }
 

test/services/base_service.test.js

@@ -0,0 +1,119 @@
+/* eslint-disable func-names */
+import { expect } from 'chai';
+
+import EasyPostClient from '../../src/easypost';
+import EndOfPaginationError from '../../src/errors/general/end_of_pagination_error';
+import * as setupPolly from '../helpers/setup_polly';
+import {
+  MockMiddleware,
+  MockRequest,
+  MockRequestMatchRule,
+  MockRequestResponseInfo,
+} from '../helpers/mocking';
+
+describe('Base Service', function () {
+  setupPolly.startPolly();
+
+  beforeEach(function () {
+    const { server } = this.polly;
+    setupPolly.setupCassette(server);
+  });
+
+  it('getNextPage collects all pages', async function () {
+    const pageSize = 1; // Doesn't matter what this is, we're mocking the response
+
+    let allResults = [];
+    let previousPage = null;
+
+    // Using scanforms as an example, but this should work for any service since it's a base class method
+    // Mock the initial "get all scanforms" call
+    let firstPageResponse = {
+      scan_forms: [
+        {
+          id: 'sf_123',
+        },
+      ],
+      has_more: true,
+    };
+    let middleware = (request) => {
+      return new MockMiddleware(request, [
+        new MockRequest(
+          new MockRequestMatchRule('GET', 'v2\\/scan_forms'),
+          new MockRequestResponseInfo(200, firstPageResponse),
+        ),
+      ]);
+    };
+    this.client = new EasyPostClient(process.env.EASYPOST_TEST_API_KEY, {
+      requestMiddleware: middleware,
+    });
+
+    let firstPage = await this.client.ScanForm.all({ page_size: pageSize });
+    allResults = allResults.concat(firstPage.scan_forms);
+    previousPage = firstPage;
+
+    // Mock the first "get next page" call with more to collect after
+    // (current page "has_more" = True, next page "has_more" = True)
+    let secondPageResponse = {
+      scan_forms: [
+        {
+          id: 'sf_456',
+        },
+      ],
+      has_more: true,
+    };
+    middleware = (request) => {
+      return new MockMiddleware(request, [
+        new MockRequest(
+          new MockRequestMatchRule('GET', 'v2\\/scan_forms'),
+          new MockRequestResponseInfo(200, secondPageResponse),
+        ),
+      ]);
+    };
+    this.client = new EasyPostClient(process.env.EASYPOST_TEST_API_KEY, {
+      requestMiddleware: middleware,
+    });
+
+    let secondPage = await this.client.ScanForm.getNextPage(previousPage, pageSize);
+    allResults = allResults.concat(secondPage.scan_forms);
+    previousPage = secondPage;
+
+    // Mock the second "get next page" call with no more to collect after
+    // (current page "has_more" = True, next page "has_more" = False)
+    let thirdPageResponse = {
+      scan_forms: [
+        {
+          id: 'sf_789',
+        },
+      ],
+      has_more: false,
+    };
+    middleware = (request) => {
+      return new MockMiddleware(request, [
+        new MockRequest(
+          new MockRequestMatchRule('GET', 'v2\\/scan_forms'),
+          new MockRequestResponseInfo(200, thirdPageResponse),
+        ),
+      ]);
+    };
+    this.client = new EasyPostClient(process.env.EASYPOST_TEST_API_KEY, {
+      requestMiddleware: middleware,
+    });
+
+    let thirdPage = await this.client.ScanForm.getNextPage(previousPage, pageSize);
+    allResults = allResults.concat(thirdPage.scan_forms);
+    previousPage = thirdPage;
+
+    // Verify we have all scanforms (from the initial "get all scanforms" and two subsequent "get next page" calls)
+    // Ensures no guard clauses inside the "get next page" method are preventing us from collecting all scanforms
+    expect(allResults.length).to.equal(3);
+
+    // Now that the previous page has "has_more" = False, it should throw an error before even making the API call
+    try {
+      await this.client.ScanForm.getNextPage(previousPage, pageSize);
+      // if the above line doesn't throw an error, the test should fail
+      expect.fail();
+    } catch (error) {
+      expect(error).instanceOf(EndOfPaginationError);
+    }
+  });
+});