From 5560d6ab8bca5db96ca41c4e8c581b4dfa0a3931 Mon Sep 17 00:00:00 2001
From: Robert DeLuca <robertdeluca19@gmail.com>
Date: Wed, 3 Apr 2019 17:21:37 -0500
Subject: [PATCH] feat: Add `healthcheck` command (#122)

* Implement healthcheck command

* Update ci cache key

This should fix the following error in CI:

```
error computing cache key: template: cacheKey:1:47: executing "cacheKey" at <checksum "yarn.lock">: error calling checksum: open /home/circleci/cli/yarn.lock: no such file or directory
```

This is because we don't actually have a yarn lock file

* Make the linter happy

* Extend `Command`, remove `percyWillRun`.
---
 .circleci/config.yml               |  2 +-
 src/commands/health-check.ts       | 31 ++++++++++++++++++
 src/utils/health-checker.ts        |  3 +-
 test/commands/health-check.test.ts | 52 ++++++++++++++++++++++++++++++
 4 files changed, 86 insertions(+), 2 deletions(-)
 create mode 100644 src/commands/health-check.ts
 create mode 100644 test/commands/health-check.test.ts

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 1400df67..f658c0df 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -12,7 +12,7 @@ jobs:
       - checkout
       - restore_cache: &restore_cache
           keys:
-            - v1-yarn-{{checksum ".circleci/config.yml"}}-{{ checksum "yarn.lock"}}
+            - v1-yarn-{{checksum ".circleci/config.yml"}}-{{ checksum "package-lock.json"}}
             - v1-yarn-{{checksum ".circleci/config.yml"}}
       - run: .circleci/greenkeeper
       - run: yarn add -D nyc@11 @oclif/nyc-config@1 mocha-junit-reporter@1
diff --git a/src/commands/health-check.ts b/src/commands/health-check.ts
new file mode 100644
index 00000000..b34a23d1
--- /dev/null
+++ b/src/commands/health-check.ts
@@ -0,0 +1,31 @@
+import {Command, flags} from '@oclif/command'
+import * as colors from 'colors'
+import Constants from '../services/constants'
+import healthCheck from '../utils/health-checker'
+
+export default class HealthCheck extends Command {
+  static description = 'Determines if the Percy Agent process is currently running'
+  static hidden = true
+
+  static flags = {
+    port: flags.integer({
+      char: 'p',
+      default: Constants.PORT,
+      description: 'port',
+    }),
+  }
+
+  static examples = [
+    '$ percy healthcheck',
+    '$ percy healthcheck --port 6884',
+  ]
+
+  async run() {
+    const {flags} = this.parse(HealthCheck)
+    const port = flags.port as number
+
+    await healthCheck(port, {
+      shouldRetry: () => false,
+    })
+  }
+}
diff --git a/src/utils/health-checker.ts b/src/utils/health-checker.ts
index 4253e785..b41ef356 100644
--- a/src/utils/health-checker.ts
+++ b/src/utils/health-checker.ts
@@ -2,13 +2,14 @@ import Axios from 'axios'
 import * as retryAxios from 'retry-axios'
 import logger from './logger'
 
-async function healthCheck(port: number) {
+async function healthCheck(port: number, retryOptions?: object) {
   const healthcheckUrl = `http://localhost:${port}/percy/healthcheck`
 
   const retryConfig = {
     retry: 5, // with exponential back off
     retryDelay: 500,
     shouldRetry: () => true,
+    ...retryOptions,
   }
 
   const interceptorId = retryAxios.attach()
diff --git a/test/commands/health-check.test.ts b/test/commands/health-check.test.ts
new file mode 100644
index 00000000..63489185
--- /dev/null
+++ b/test/commands/health-check.test.ts
@@ -0,0 +1,52 @@
+import * as chai from 'chai'
+import {describe} from 'mocha'
+import * as nock from 'nock'
+import HealthCheck from '../../src/commands/health-check'
+import {captureStdErr, captureStdOut} from '../helpers/stdout'
+
+const expect = chai.expect
+
+describe('Health check', () => {
+  describe('when agent is running', () => {
+    beforeEach(() => {
+      nock(/localhost/).get('/percy/healthcheck').reply(200)
+    })
+
+    afterEach(() => {
+      nock.cleanAll()
+    })
+
+    it('messages that agent is ready', async () => {
+      const stdout = await captureStdOut(async () => HealthCheck.run([]))
+
+      expect(stdout).to.contain('[percy] percy is ready.')
+    })
+  })
+
+  describe('when agent is not running', () => {
+    beforeEach(() => {
+      nock(/localhost/).get('/percy/healthcheck').reply(500)
+    })
+
+    afterEach(() => {
+      nock.cleanAll()
+    })
+
+    it('messages that agent is not ready', async () => {
+      const errorStdout = await captureStdErr(async () => HealthCheck.run([]))
+
+      expect(errorStdout).to
+        .contain('[percy] Failed to establish a connection with http://localhost:5338/percy/healthcheck')
+    })
+
+    it('properly passes the port', async () => {
+      const port = '5899'
+      const errorStdout = await captureStdErr(async () =>
+        HealthCheck.run(['--port', port]),
+      )
+
+      expect(errorStdout).to
+        .contain('[percy] Failed to establish a connection with http://localhost:5899/percy/healthcheck')
+    })
+  })
+})