Address PR comments; use os.constants

bin/mocha.js

@@ -23,6 +23,9 @@ const {aliases} = require('../lib/cli/run-option-metadata');
 
 const mochaArgs = {};
 const nodeArgs = {};
+const EXIT_SUCCESS = 0;
+const EXIT_FAILURE = 1;
+const SIGNAL_OFFSET= 128;
 let hasInspect = false;
 
 const opts = loadOptions(process.argv.slice(2));
@@ -113,12 +116,14 @@ if (mochaArgs['node-option'] || Object.keys(nodeArgs).length || hasInspect) {
         const numericSignal =
           typeof signal === 'string' ? os.constants.signals[signal] : signal;
         if (mochaArgs['posix-exit-codes'] === true) {
-          process.exit(128 + numericSignal);
+          process.exit(SIGNAL_OFFSET + numericSignal);
         } else {
           process.kill(process.pid, signal);
         }
+      } else if (code !== 0 && mochaArgs['posix-exit-codes'] === true) {
+        process.exit(EXIT_FAILURE);
       } else {
-        process.exit((mochaArgs['posix-exit-codes'] === true) ? 0 : code);
+        process.exit(code);
       }
     });
   });

lib/cli/run.js

@@ -191,7 +191,7 @@ exports.builder = yargs =>
         group: GROUPS.RULES
       },
       'posix-exit-codes': {
-        description: 'Use posix exit codes for fatal signals',
+        description: 'Use POSIX and UNIX shell exit codes as Mocha\'s return value',
         group: GROUPS.RULES
       },
       recursive: {

test/integration/fixtures/failing.fixture.js

@@ -0,0 +1,23 @@
+'use strict';
+
+// One passing test and three failing tests
+
+var assert = require('assert');
+
+describe('suite', function () {
+  it('test1', function () {
+    assert(true);
+  });
+
+  it('test2', function () {
+    assert(false);
+  });
+
+  it('test3', function () {
+    assert(false);
+  });
+
+  it('test4', function () {
+    assert(false);
+  });
+});

test/integration/options/posixExitCodes.spec.js

@@ -2,40 +2,45 @@
 
 var helpers = require('../helpers');
 var runMocha = helpers.runMocha;
+var os = require('os');
+
+const EXIT_SUCCESS = 0;
+const EXIT_FAILURE = 1;
+const SIGNAL_OFFSET = 128;
 
 describe('--posix-exit-codes', function () {
   describe('when enabled, and with node options', function () {
     var args = ['--no-warnings', '--posix-exit-codes'];
 
-    it('should exit with code 134 on SIGABRT', function (done) {
+    it('should exit with correct POSIX shell code on SIGABRT', function (done) {
       var fixture = 'signals-sigabrt.fixture.js';
       runMocha(fixture, args, function postmortem(err, res) {
         if (err) {
           return done(err);
         }
-        expect(res.code, 'to be', 134);
+        expect(res.code, 'to be', SIGNAL_OFFSET + os.constants.signals.SIGABRT);
         done();
       });
     });
 
-    it('should exit with code 143 on SIGTERM', function (done) {
+    it('should exit with correct POSIX shell code on SIGTERM', function (done) {
       var fixture = 'signals-sigterm.fixture.js';
       runMocha(fixture, args, function postmortem(err, res) {
         if (err) {
           return done(err);
         }
-        expect(res.code, 'to be', 143);
+        expect(res.code, 'to be', SIGNAL_OFFSET + os.constants.signals.SIGTERM);
         done();
       });
     });
 
-    it('should exit with code 0 even if there are test failures', function (done) {
+    it('should exit with code 1 if there are test failures', function (done) {
       var fixture = 'failing.fixture.js';
       runMocha(fixture, args, function postmortem(err, res) {
         if (err) {
           return done(err);
         }
-        expect(res.code, 'to be', 0);
+        expect(res.code, 'to be', EXIT_FAILURE);
         done();
       });
     });
@@ -55,13 +60,14 @@ describe('--posix-exit-codes', function () {
     });
 
     it('should exit with the number of failed tests', function (done) {
-      var fixture = 'failing.fixture.js'; // one failing test
+      var fixture = 'failing.fixture.js'; // contains three failing tests
+      var numFailures = 3;
       var args = ['--no-warnings'];
       runMocha(fixture, args, function postmortem(err, res) {
         if (err) {
           return done(err);
         }
-        expect(res.code, 'to be', 1);
+        expect(res.code, 'to be', numFailures);
         done();
       });
     });