test-main.js

var allTestFiles = [];
var TEST_REGEXP = /(spec|tests)\.js$/i;

// Get a list of all the test files to include
Object.keys(window.__karma__.files).forEach(function (file) {
  if (TEST_REGEXP.test(file)) {
    // Normalize paths to RequireJS module names.
    // If you require sub-dependencies of test files to be loaded as-is (requiring file extension)
    // then do not normalize the paths
    var normalizedTestModule = file.replace(/^\/base\/|\.js$/g, '');
    allTestFiles.push(normalizedTestModule);
  }
})

require.config({
  // Karma serves files under /base, which is the basePath from your config file
  baseUrl: '/base',

  paths: {
    "chai": "node_modules/chai/chai"
  },

  // dynamically load all test files
  deps: allTestFiles,

  callback: window.__karma__.start
});