fix(readme): decode base64 content from octokit before handling

README.md

@@ -98,7 +98,7 @@ You can display this badge somewhere in your readme as below, which will render
 ![!monkeytype.badge]
 
 <!-- For clickable image that links to monkeytype website -->
-[![!monkeytype.badge]](https://monkeytype.com/)
+[![monkeytype.badge]](https://monkeytype.com/)
 ```
 
 #### 2. Monkeytype API Key

src/readme/readme.test.ts

@@ -26,7 +26,8 @@ jest.mock('@actions/github', () => ({
       repos: {
         getReadme: jest.fn(async () => ({
           data: {
-            content,
+            content: Buffer.from(content).toString('base64'),
+            encoding: 'base64',
             path: 'README.md',
             sha: '802992c4220de19a90767f3000a79a31b98d0df7',
           }
@@ -40,14 +41,14 @@ jest.mock('@actions/github', () => ({
 test('Default input should update', async () => {
   const coreInfoSpy = jest.spyOn(core, 'info');
   const newContent = await updateReadme(defaultInput, badgeUrl);
-  expect(coreInfoSpy).toHaveBeenCalledTimes(1);
+  expect(coreInfoSpy).toHaveBeenCalled();
   expect(newContent).toBe(content.replace(REGEX, `[monkeytype.badge]: ${badgeUrl}`));
 });
 
 test('Same content should skip', async () => {
   const coreInfoSpy = jest.spyOn(core, 'info');
   const newContent = await updateReadme(defaultInput, exampleUrl);
-  expect(coreInfoSpy).toHaveBeenCalledTimes(1);
+  expect(coreInfoSpy).toHaveBeenCalled();
   expect(newContent).toBe(content);
 });
 

src/readme/readme.ts

@@ -4,13 +4,17 @@ import * as github from '@actions/github';
 import { BadgeResourceDeclarationNotFoundError } from '../error';
 import type { Input } from '../input';
 
-export const REGEX = /\[monkeytype\.badge\].*$/m;
+export const REGEX = /(?<!!)\[monkeytype\.badge\].*$/m;
 
 export async function updateReadme(input: Input, badgeUrl: string) {
   const octokit = github.getOctokit(input.github_token);
   const { repo, owner } = github.context.repo;
+
+  core.info(`Getting README.md content from ${owner}/${repo}`);
   const readme = await octokit.rest.repos.getReadme({ owner, repo });
-  let content = readme.data.content;
+  core.info(readme.data.content);
+  let content = Buffer.from(readme.data.content, readme.data.encoding as BufferEncoding).toString('utf-8');
+
   const newBadgeResource = `[monkeytype.badge]: ${badgeUrl}`;
   const badgeResource = content.match(REGEX)?.[0];
   if (!badgeResource) {