$ PROJECT="/var/tmp/ypdbldash"

$ mkdir ${PROJECT}
$ cd ${PROJECT}
$ mkdir test
$ touch index.js
$ cat << EOF >> "package.json"
{
  "name": "ypdbldash",
  "version": "1.0.0",
  "description": "Test end-of-options (double-dash) argument placement",
  "main": "index.js",
  "directories": {
    "test": "./test"
  },
  "scripts": {
    "test": "mocha"
  },
  "devDependencies": {
    "mocha": "latest",
    "unexpected": "latest",
    "yargs-parser": "latest"
  },
  "engines": {
    "node": ">=6"
  },
  "keywords": [
    "argv",
    "double-dash"
  ],
  "author": "P. Roebuck <plroebuck@users.noreply.github.com>",
  "license": "CC0-1.0"
}
EOF
$ cat << EOF >> "test/3899.spec.js"
'use strict';
  
const expect = require('unexpected');
const yargsParser = require('yargs-parser');

describe('mochajs/mocha#3899', function() {
  const filename = 'somefile';
  const args = [
    '--',
    filename
  ];

  context('when given empty config', () => {
    let result;
    const configuration = {};

    before(function() {
      //console.log('configuration:', configuration);
      result = yargsParser.detailed(args, {configuration});
      //console.log(result);
    });

    it('should not error', () => {
      expect(result.error, 'to be null');
    });

    it('should not create a "-" alias', () => {
      expect(result.newAliases, 'to be empty');
    });

    it('should not populate "-" with positional arg', () => {
      expect(result.argv, 'not to have key', '-');
    });

    it('should populate "_" with positional arg', () => {
      expect(result.argv['_'], 'to equal', [ filename ]);
    });
  });

  context("when given config with 'short-option-groups' false", () => {
    let result;
    const configuration = {
      'short-option-groups': false
    };

    before(function() {
      //console.log('configuration:', configuration);
      result = yargsParser.detailed(args, {configuration});
      //console.log(result);
    });

    it('should denote use of input configuration settings', () => {
      expect(result.configuration, 'to satisfy', {
        ...configuration
      });
    });

    it('should not error', () => {
      expect(result.error, 'to be null');
    });

    it('should not create a "-" alias', () => {
      expect(result.newAliases, 'to be empty');
    });

    it('should not populate "-" with positional arg', () => {
      expect(result.argv, 'not to have key', '-');
    });

    it('should populate "_" with positional arg', () => {
      expect(result.argv['_'], 'to equal', [ filename ]);
    });
  });

  context("when given config with both 'short-option-groups' and 'camel-case-expansion' false", () => {
    let result;
    const configuration = {
      'camel-case-expansion': false,
      'short-option-groups': false
    };

    before(function() {
      //console.log('configuration:', configuration);
      result = yargsParser.detailed(args, { configuration });
      //console.log(result);
    });

    it('should denote use of input configuration settings', () => {
      expect(result.configuration, 'to satisfy', {
        ...configuration
      });
    });

    it('should not error', () => {
      expect(result.error, 'to be null');
    });

    it('should not create a "-" alias', () => {
      expect(result.newAliases, 'to be empty');
    });

    it('should not populate "-" with positional arg', () => {
      expect(result.argv, 'not to have key', '-');
    });

    it('should populate "_" with positional arg', () => {
      expect(result.argv['_'], 'to equal', [ filename ]);
    });
  });
});
EOF
$ npm install

$ npm test