build(typescript): refactoring project with typescript and test setup

__tests__/add-pr-comment.test.ts

@@ -0,0 +1,41 @@
+import * as core from '@actions/core'
+import * as github from '@actions/github'
+import {WebhookPayload} from '@actions/github/lib/interfaces'
+import run from '../add-pr-comment'
+
+beforeEach(() => {
+  jest.resetModules()
+  jest.spyOn(core, 'getInput').mockImplementation((name: string): string => {
+    switch (name) {
+      case 'message':
+        return 'hello world'
+      case 'repo-token':
+        return '12345'
+      case 'allow-repeats':
+        return 'false'
+      default:
+        return ''
+    }
+  })
+
+  // https://developer.github.com/webhooks/event-payloads/#issues
+  github.context.payload = {
+    action: 'created',
+    issue: {
+      number: 1,
+    },
+    comment: {
+      id: 1,
+      user: {
+        login: 'monalisa',
+      },
+      body: 'Honk',
+    },
+  } as WebhookPayload
+})
+
+describe('add-pr-comment action', () => {
+  it('runs', async () => {
+    await expect(run()).resolves.not.toThrow()
+  })
+})