feat(karma): test bson in the browser

* revert back to previous version of browser testing

* should run on travis now

* package lock

* updated package.json to not need build

* remove buffers necessary for wrong package.json version

.travis.yml

@@ -2,14 +2,17 @@ sudo: false
 dist: trusty
 
 language: node_js
+node_js:
+  - 4
+  - 6
+  - 8
+  - 10
 
 cache:
   yarn: true
   directories:
     - node_modules
 
-node_js:
-  - 4
-  - 6
-  - 8
-  - 10
+script:
+  - npm run-script test-node
+  - if [[ $(node --version) != v4* ]] ; then npm run-script test-browser; fi

karma.conf.js

@@ -0,0 +1,66 @@
+'use strict';
+
+const scenariosPlugin = require('./tools/scenarios-plugin');
+const jsonPlugin = require('rollup-plugin-json');
+const nodeGlobals = require('rollup-plugin-node-globals');
+const nodeBuiltins = require('rollup-plugin-node-builtins');
+const commonjs = require('rollup-plugin-commonjs');
+const nodeResolve = require('rollup-plugin-node-resolve');
+
+const rollupPlugins = [
+  scenariosPlugin(),
+  nodeResolve({
+    browser: true,
+    preferBuiltins: false
+  }),
+  commonjs({
+    namedExports: {
+      'node_modules/buffer/index.js': ['isBuffer']
+    }
+  }),
+  nodeBuiltins(),
+  nodeGlobals(),
+  jsonPlugin()
+];
+
+const rollupConfig = {
+  plugins: rollupPlugins,
+  output: {
+    format: 'iife',
+    name: 'BSONtest',
+    exports: 'named'
+  }
+};
+
+const onwarn = warning => {
+  if (warning.code === 'CIRCULAR_DEPENDENCY' || warning.code === 'EVAL') return;
+  console.warn(warning.toString());
+};
+
+rollupConfig.onwarn = onwarn;
+
+module.exports = function(config) {
+  config.set({
+    basePath: '',
+    frameworks: ['mocha'],
+    reporters: ['mocha'],
+    files: [{ pattern: 'test/node/!(bson_node_only_tests).js', watched: false }],
+    preprocessors: {
+      'test/node/!(bson_node_only_tests).js': 'rollup'
+    },
+    rollupPreprocessor: rollupConfig,
+    port: 9876,
+    colors: true,
+    logLevel: config.LOG_INFO,
+    autoWatch: true,
+    browsers: ['ChromeHeadlessNoSandbox'],
+    customLaunchers: {
+      ChromeHeadlessNoSandbox: {
+        base: 'ChromeHeadless',
+        flags: ['--no-sandbox']
+      }
+    },
+    singleRun: true,
+    concurrency: Infinity
+  });
+};