How to set up rollup with karma and babel? - karma-runner

Question

I try to set up rollup with karma and babel for test.
I face two problems.
First, it cause error Uncaught TypeError about default.
Uncaught TypeError: Cannot use 'in' operator to search for 'default' in undefined
Second, it doesn't find external dependency.
Treating 'chai' as external dependency
What's wrong in my settings?
rollup conf
import babel from "rollup-plugin-babel";
import babelrc from "babelrc-rollup";
import istanbul from "rollup-plugin-istanbul";
import nodeResolve from "rollup-plugin-node-resolve";
import commonjs from "rollup-plugin-commonjs";
import builtins from "rollup-plugin-node-builtins";
import globals from "rollup-plugin-node-globals";
// import uglify from 'rollup-plugin-uglify'
let pkg = require('./package.json');
let external = Object.keys(pkg.dependencies);
export default {
entry: 'src/index.js',
plugins: [
babel(babelrc()),
istanbul({
exclude: ['test/**/*', 'node_modules/**/*']
}),
globals(),
builtins(),
nodeResolve({
module: true,
jsnext: true,
main: true,
browser: true,
extensions: ['.js']
}),
commonjs({
include: 'node_modules/**'
}),
//uglify(),
],
external: external,
targets: [
{
dest: pkg.main,
format: 'umd',
moduleName: 'sketchbook',
sourceMap: true
},
{
dest: pkg.module,
format: 'es',
sourceMap: true
}
]
};
karma conf
module.exports = function (config) {
config.set({
files: [
// Watch src files for changes but
// don't load them into the browser.
{pattern: 'src/**/*.js', included: false},
'test/**/*.spec.js',
],
browsers: ['Chrome'],
preprocessors: {
'src/**/*.js': ['rollup'],
'test/**/*.spec.js': ['rollup'],
},
rollupPreprocessor: {
plugins: [
require('rollup-plugin-buble')(),
],
format: 'umd', // Helps prevent naming collisions.
moduleName: 'sketchbook', // Required for 'iife' format.
sourceMap: 'inline', // Sensible for testing.
},
customPreprocessors: {
// Clones the base preprocessor, but overwrites
// its options with those defined below.
rollupBabel: {
base: 'rollup',
options: {
// In this case, to use
// a different transpiler:
plugins: [
require('rollup-plugin-babel')(),
],
}
}
}
// frameworks: ['mocha'],
// client: {
// mocha: {
// opts: 'test/mocha.opts'
//
// // // change Karma's debug.html to the mocha web reporter
// // reporter: 'html',
// //
// // // require specific files after Mocha is initialized
// // require: [require.resolve('bdd-lazy-var/bdd_lazy_var_global')],
// //
// // // custom ui, defined in required file above
// // ui: 'bdd-lazy-var/global',
// }
// }
});
};
source