Resolve flaky tests (fetch) (#2158)

Author: TheSonOfThomp

.changeset/empty-ladybugs-call.md

@@ -0,0 +1,5 @@
+---
+'@lg-tools/slackbot': patch
+---
+
+Internal. Moves fetching logic into a separate `fetchChangelog` module

tools/slackbot/src/release-bot/utils/fetchChangelog.ts

@@ -0,0 +1,28 @@
+import fetch from 'node-fetch';
+
+import { ComponentUpdateObject } from '../release-bot.types';
+
+import { generateOutputStrings } from './generateOutputStrings';
+
+export async function fetchChangelogText(
+  component: ComponentUpdateObject,
+): Promise<string> {
+  const { shortName } = generateOutputStrings(component);
+  const rawChangelogUrl = `https://raw.githubusercontent.com/mongodb/leafygreen-ui/main/packages/${shortName}/CHANGELOG.md`;
+  const response = await fetch(rawChangelogUrl);
+  return await response.text();
+}
+
+export async function fetchLatestChangelogText(
+  component: ComponentUpdateObject,
+): Promise<string> {
+  const fullChangelogText = await fetchChangelogText(component);
+  const { version } = component;
+  const startIndex = fullChangelogText.indexOf(`## ${version}`);
+  const endIndex = fullChangelogText.indexOf(
+    `\n## `,
+    startIndex + version.length,
+  );
+  const latestChangelog = fullChangelogText.substring(startIndex, endIndex);
+  return latestChangelog;
+}

tools/slackbot/src/release-bot/utils/getSortedUpdates.spec.ts

@@ -1,37 +1,72 @@
+import { fetchChangelogText, fetchLatestChangelogText } from './fetchChangelog';
 import { getSortedUpdates } from './getSortedUpdates';
-import { TEST_DATA } from './test.data';
+import { TEST_CHANGELOG, TEST_DATA } from './test.data';
+
+jest.mock('./fetchChangelog', () => {
+  return {
+    fetchChangelogText: jest.fn(),
+    fetchLatestChangelogText: jest.fn(),
+  };
+});
 
 describe('tools/slackbot/release', () => {
+  beforeEach(() => {
+    (fetchChangelogText as jest.Mock).mockReturnValue(
+      new Promise(r => r(TEST_CHANGELOG)),
+    );
+    (fetchLatestChangelogText as jest.Mock).mockReturnValue(
+      new Promise(r => r(TEST_CHANGELOG)),
+    );
+  });
+
   describe('getSortedUpdates', () => {
     test('sorts the updates array', async () => {
       const sortedUpdates = await getSortedUpdates(TEST_DATA);
       expect(sortedUpdates).toHaveProperty(
         'major',
-        expect.objectContaining([
-          { name: '@leafygreen-ui/example-major', version: '2.0.0' },
-          { name: '@lg-tools/tool-major', version: '2.0.0' },
+        expect.arrayContaining([
+          expect.objectContaining({
+            name: '@leafygreen-ui/example-major',
+            version: '2.0.0',
+          }),
+          expect.objectContaining({
+            name: '@lg-tools/tool-major',
+            version: '2.0.0',
+          }),
         ]),
       );
 
       expect(sortedUpdates).toHaveProperty(
         'minor',
-        expect.objectContaining([
-          { name: '@leafygreen-ui/example-minor', version: '1.2.0' },
-          { name: '@lg-tools/tool-minor', version: '1.2.0' },
+        expect.arrayContaining([
+          expect.objectContaining({
+            name: '@leafygreen-ui/example-minor',
+            version: '1.2.0',
+          }),
+          expect.objectContaining({
+            name: '@lg-tools/tool-minor',
+            version: '1.2.0',
+          }),
         ]),
       );
 
       expect(sortedUpdates).toHaveProperty(
         'patch',
-        expect.objectContaining([
-          { name: '@leafygreen-ui/example-patch', version: '1.0.2' },
-          { name: '@lg-tools/tool-patch', version: '1.0.2' },
+        expect.arrayContaining([
+          expect.objectContaining({
+            name: '@leafygreen-ui/example-patch',
+            version: '1.0.2',
+          }),
+          expect.objectContaining({
+            name: '@lg-tools/tool-patch',
+            version: '1.0.2',
+          }),
         ]),
       );
 
       expect(sortedUpdates).toHaveProperty(
         'dependency',
-        expect.objectContaining([]),
+        expect.arrayContaining([]),
       );
     });
   });

tools/slackbot/src/release-bot/utils/parseChangeLog.ts

@@ -1,9 +1,8 @@
 import { uniq } from 'lodash';
-import fetch from 'node-fetch';
 
 import { ComponentUpdateObject } from '../release-bot.types';
 
-import { generateOutputStrings } from './generateOutputStrings';
+import { fetchLatestChangelogText } from './fetchChangelog';
 
 /**
  * Given a component update object
@@ -22,29 +21,6 @@ export async function parseChangeLog(component: ComponentUpdateObject) {
   };
 }
 
-async function fetchChangelogText(
-  component: ComponentUpdateObject,
-): Promise<string> {
-  const { shortName } = generateOutputStrings(component);
-  const rawChangelogUrl = `https://raw.githubusercontent.com/mongodb/leafygreen-ui/main/packages/${shortName}/CHANGELOG.md`;
-  const response = await fetch(rawChangelogUrl);
-  return await response.text();
-}
-
-async function fetchLatestChangelogText(
-  component: ComponentUpdateObject,
-): Promise<string> {
-  const fullChangelogText = await fetchChangelogText(component);
-  const { version } = component;
-  const startIndex = fullChangelogText.indexOf(`## ${version}`);
-  const endIndex = fullChangelogText.indexOf(
-    `\n## `,
-    startIndex + version.length,
-  );
-  const latestChangelog = fullChangelogText.substring(startIndex, endIndex);
-  return latestChangelog;
-}
-
 const majorChangeIndex = (changelog: string) =>
   changelog.indexOf(`### Major Changes`) >= 0
     ? changelog.indexOf(`### Major Changes`)

tools/slackbot/src/release-bot/utils/test.data.ts

@@ -6,3 +6,12 @@ export const TEST_DATA = [
   { name: '@lg-tools/tool-minor', version: '1.2.0' },
   { name: '@lg-tools/tool-patch', version: '1.0.2' },
 ];
+
+export const TEST_CHANGELOG = `
+  # example-major
+
+  ## 2.0.0
+
+  ### Major Changes
+  - Major update
+`;