test: refactor/cleanup a number of cluster tests

* Move shared code into common
* Favor use of strictEqual
* Add some missing common.mustCalls
* Other general cleanup

PR-URL: https://github.com/nodejs/node/pull/8261
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>

1 files changed, 26 insertions, 42 deletions

diff --git a/test/parallel/test-cluster-master-error.js b/test/parallel/test-cluster-master-error.js
index 1f0cb8c909..6f9c78a7ba 100644
--- a/test/parallel/test-cluster-master-error.js
+++ b/test/parallel/test-cluster-master-error.js
@@ -1,22 +1,22 @@
 'use strict';
-var common = require('../common');
-var assert = require('assert');
-var cluster = require('cluster');
+const common = require('../common');
+const assert = require('assert');
+const cluster = require('cluster');
+
+const totalWorkers = 2;
 
 // Cluster setup
 if (cluster.isWorker) {
-  var http = require('http');
-  http.Server(function() {
+  const http = require('http');
+  http.Server(() => {
 
   }).listen(common.PORT, '127.0.0.1');
 
 } else if (process.argv[2] === 'cluster') {
 
-  var totalWorkers = 2;
-
   // Send PID to testcase process
   var forkNum = 0;
-  cluster.on('fork', function forkEvent(worker) {
+  cluster.on('fork', common.mustCall(function forkEvent(worker) {
 
     // Send PID
     process.send({
@@ -28,11 +28,11 @@ if (cluster.isWorker) {
     if (++forkNum === totalWorkers) {
       cluster.removeListener('fork', forkEvent);
     }
-  });
+  }));
 
   // Throw accidental error when all workers are listening
   var listeningNum = 0;
-  cluster.on('listening', function listeningEvent() {
+  cluster.on('listening', common.mustCall(function listeningEvent() {
 
     // When all workers are listening
     if (++listeningNum === totalWorkers) {
@@ -40,13 +40,12 @@ if (cluster.isWorker) {
       cluster.removeListener('listening', listeningEvent);
 
       // Throw accidental error
-      process.nextTick(function() {
-        console.error('about to throw');
+      process.nextTick(() => {
         throw new Error('accidental error');
       });
     }
 
-  });
+  }));
 
   // Startup a basic cluster
   cluster.fork();
@@ -55,51 +54,36 @@ if (cluster.isWorker) {
 } else {
   // This is the testcase
 
-  var fork = require('child_process').fork;
-
-  var isAlive = function(pid) {
-    try {
-      //this will throw an error if the process is dead
-      process.kill(pid, 0);
-
-      return true;
-    } catch (e) {
-      return false;
-    }
-  };
+  const fork = require('child_process').fork;
 
   var masterExited = false;
   var workersExited = false;
 
   // List all workers
-  var workers = [];
+  const workers = [];
 
   // Spawn a cluster process
-  var master = fork(process.argv[1], ['cluster'], {silent: true});
+  const master = fork(process.argv[1], ['cluster'], {silent: true});
 
   // Handle messages from the cluster
-  master.on('message', function(data) {
+  master.on('message', common.mustCall((data) => {
 
     // Add worker pid to list and progress tracker
     if (data.cmd === 'worker') {
       workers.push(data.workerPID);
     }
-  });
+  }, totalWorkers));
 
   // When cluster is dead
-  master.on('exit', function(code) {
+  master.on('exit', common.mustCall((code) => {
 
     // Check that the cluster died accidentally (non-zero exit code)
     masterExited = !!code;
 
-    var pollWorkers = function() {
+    const pollWorkers = function() {
       // When master is dead all workers should be dead too
       var alive = false;
-      workers.forEach(function(pid) {
-        if (isAlive(pid)) {
-          alive = true;
-        }
-      });
+      workers.forEach((pid) => alive = common.isAlive(pid));
       if (alive) {
         setTimeout(pollWorkers, 50);
       } else {
@@ -109,13 +93,13 @@ if (cluster.isWorker) {
 
     // Loop indefinitely until worker exit
     pollWorkers();
-  });
+  }));
 
-  process.once('exit', function() {
-    var m = 'The master did not die after an error was thrown';
-    assert.ok(masterExited, m);
-    m = 'The workers did not die after an error in the master';
-    assert.ok(workersExited, m);
+  process.once('exit', () => {
+    assert(masterExited,
+           'The master did not die after an error was thrown');
+    assert(workersExited,
+           'The workers did not die after an error in the master');
   });
 
 }