refactor(samples): convert sample tests from ava to mocha

samples/package.json

@@ -9,13 +9,10 @@
     "node": ">=8"
   },
   "scripts": {
-    "ava": "ava -T 20s --verbose test/*.test.js system-test/*.test.js",
-    "cover": "nyc --reporter=lcov --cache ava -T 20s --verbose test/*.test.js system-test/*.test.js && nyc report",
     "error-test": "samples test app --msg \"Something broke!\" --url \"http://localhost:33332/error\" --port 33332  -- snippets.js express",
     "exception-test": "samples test app --code 500 --msg SyntaxError --url \"http://localhost:33333/exception\" --port 33333  -- snippets.js express",
-    "system-test": "ava -T 1m --verbose system-test/*.test.js",
-    "all-test": "npm run system-test && npm run error-test && npm run exception-test",
-    "test": "npm run cover"
+    "all-test": "npm run test && npm run error-test && npm run exception-test",
+    "test": "mocha system-test/*.test.js --timeout=600000"
   },
   "dependencies": {
     "@google-cloud/error-reporting": "^0.5.0",
@@ -24,8 +21,7 @@
   },
   "devDependencies": {
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
-    "ava": "^0.25.0",
-    "nyc": "^13.0.0",
+    "mocha": "^5.2.0",
     "proxyquire": "^2.0.1",
     "sinon": "^7.0.0"
   }

samples/system-test/.eslintrc.yml

@@ -1,5 +1,6 @@
 ---
+env:
+  mocha: true
 rules:
   node/no-unpublished-require: off
-  node/no-unsupported-features: off
   no-empty: off

samples/system-test/snippets.test.js

@@ -15,24 +15,22 @@
 
 'use strict';
 
-const path = require(`path`);
-const test = require(`ava`);
-const tools = require(`@google-cloud/nodejs-repo-tools`);
+const path = require('path');
+const assert = require('assert');
+const tools = require('@google-cloud/nodejs-repo-tools');
 
-const cwd = path.join(__dirname, `..`);
-const cmd = `node snippets.js`;
+const cwd = path.join(__dirname, '..');
+const cmd = 'node snippets.js';
 
-test.before(tools.checkCredentials);
+before(tools.checkCredentials);
 
-test.serial(`should setup using implicit credentials`, async t => {
-  t.plan(0);
+it('should setup using implicit credentials', async () =>
   // There's no output, the command should just succeed
-  await tools.runAsync(`${cmd} setup-implicit`, cwd);
-});
+  await tools.runAsync(`${cmd} setup-implicit`, cwd));
 
-test.serial(`should report errors manually`, async t => {
+it('should report errors manually', async () => {
   const output = await tools.runAsync(`${cmd} manual`, cwd);
-  t.is(output.includes('Done reporting error event!'), true);
-  t.is(output.includes('Done reporting Error object!'), true);
-  t.is(output.includes('Done reporting error string!'), true);
+  assert.strictEqual(output.includes('Done reporting error event!'), true);
+  assert.strictEqual(output.includes('Done reporting Error object!'), true);
+  assert.strictEqual(output.includes('Done reporting error string!'), true);
 });