Karma coverage always showing 100% vue

[Eccentris]

Hi! I can't seem to get my coverage to show correctly, but the unit tests are running as they should. The coverage always shows 100% like so:

Coverage summary Statements : 100% ( 0/0 ) Branches : 100% ( 0/0 ) Functions : 100% ( 0/0 ) Lines : 100% ( 0/0 )

----------	----------	----------	----------	----------	----------------	File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Lines
----------	----------	----------	----------	----------	----------------
All files	100	100	100 .	100
----------	----------	----------	----------	----------	----------------

My karma.conf.js looks like this

module.exports = function(config) {

  var autoprefixer = require('autoprefixer');
  process.env.BABEL_ENV = 'testing-unit';

  config.set({

    basePath: '',

    frameworks: ['jasmine', 'browserify'],

    browserify: {
        debug: true,
        transform: [
            ['vueify', {
                postcss: [autoprefixer(
                    {browsers: ['last 2 versions', 'ie 11']})]
            }],
            ['babelify']
        ],
    },

    files: [
        'tests/js/**/*.js'
    ],

    preprocessors: {
      '/src/js/**/*.vue': ['coverage'],
      '/src/js/**/*.js': ['coverage'],
      'tests/js/**/*.js': ['browserify']
    },

    reporters: ['spec', 'coverage'],

    coverageReporter: {
        dir: 'reports/coverage/javascript',
        includeAllSources: true,
        reporters: [
            { type: 'lcov', subdir: '.' },
            { type: 'text-summary' },
            { type: 'text' },
            { type: 'cobertura', subdir: '.', file: 'coverage.xml' }
        ]
    },

    junitReporter: {
        outputFile: 'reports/test-results.xml',
        useBrowserName: false
    },

    port: 9876,

    colors: true,

    logLevel: config.LOG_INFO,

    autoWatch: false,

    browsers: ['PhantomJS'],

    singleRun: false,

    concurrency: Infinity
  })
}

I've only written tests for one vue file, covering maybe 50% of that file, but I have many more untested src files so I'd expect the coverage to be much lower.

My package.json:

  "devDependencies": {
    "@mapbox/stylelint-processor-arbitrary-tags": "^0.2.0",
    "@vue/test-utils": "^1.0.0-beta.13",
    "ajv": "^5.3.0",
    "autoprefixer": "^7.1.4",
    "babel-cli": "^6.26.0",
    "babel-preset-env": "^1.6.1",
    "babelify": "^8.0.0",
    "eslint": "^4.17.0",
    "eslint-plugin-vue": "4.3.0",
    "grunt": "^1.0.2",
    "grunt-browserify": "^5.2.0",
    "grunt-contrib-clean": "^1.1.0",
    "grunt-contrib-copy": "^1.0.0",
    "grunt-contrib-less": "^1.4.1",
    "grunt-contrib-watch": "^1.0.0",
    "grunt-eslint": "^20.1.0",
    "grunt-postcss": "^0.9.0",
    "grunt-stylelint": "^0.9.0",
    "jasmine": "^2.5.3",
    "karma": "^2.0.0",
    "karma-browserify": "^5.3.0",
    "karma-cli": "^1.0.1",
    "karma-coverage": "^1.1.1",
    "karma-jasmine": "^1.1.1",
    "karma-junit-reporter": "^1.2.0",
    "karma-phantomjs-launcher": "^1.0.4",
    "karma-spec-reporter": "0.0.32",
    "stylelint": "^8.2.0",
    "stylelint-config-standard": "^17.0.0",
    "vueify": "^9.4.1"
  },
  "dependencies": {
    "@fortawesome/fontawesome": "^1.1.5",
    "@fortawesome/fontawesome-free-solid": "^5.0.10",
    "@fortawesome/vue-fontawesome": "0.0.22",
    "core-js": "^2.5.3",
    "normalize.css": "^7.0.0",
    "pikaday": "^1.6.1",
    "v-tooltip": "^2.0.0-rc.32",
    "vue": "^2.5.13",
    "whatwg-fetch": "^2.0.4"
  },
  "browser": {
    "vue": "vue/dist/vue.common.js"
  },
  "scripts": {
    "test": "npm run test:browser",
    "test:browser": "karma start --single-run --browsers PhantomJS",
    "test:ci": "npm run test:browser -- --reporters spec,coverage,junit"
  }

[Eccentris]

Found the issue, it was due to using karma coverage and browserify at the same time. Using browserify-istanbul solved it.