fix: "codeceptjs" command outputs help message twice

bin/codecept.js

@@ -236,5 +236,6 @@ program.on('command:*', (cmd) => {
 
 if (process.argv.length <= 2) {
   program.outputHelp();
+} else {
+  program.parse(process.argv);
 }
-program.parse(process.argv);

test/runner/help_test.js

@@ -0,0 +1,37 @@
+const assert = require('assert');
+const path = require('path');
+const exec = require('child_process').exec;
+
+const runner = path.join(__dirname, '/../../bin/codecept.js');
+
+describe('help option', () => {
+  it('should print help message with --help option', (done) => {
+    exec(`${runner} --help`, (err, stdout) => {
+      stdout.should.include('Usage:');
+      stdout.should.include('Options:');
+      stdout.should.include('Commands:');
+      assert(!err);
+      done();
+    });
+  });
+
+  it('should print help message with -h option', (done) => {
+    exec(`${runner} -h`, (err, stdout) => {
+      stdout.should.include('Usage:');
+      stdout.should.include('Options:');
+      stdout.should.include('Commands:');
+      assert(!err);
+      done();
+    });
+  });
+
+  it('should print help message with no option', (done) => {
+    exec(`${runner}`, (err, stdout) => {
+      stdout.should.include('Usage:');
+      stdout.should.include('Options:');
+      stdout.should.include('Commands:');
+      assert(!err);
+      done();
+    });
+  });
+});