Allow setting karma middleware options as overridable (#160)

packages/neutrino-preset-karma/index.js

@@ -2,10 +2,9 @@ const { Server } = require('karma');
 const merge = require('deepmerge');
 const { join } = require('path');
 
-module.exports = (neutrino) => {
-  neutrino.on('test', ({ files, watch }) => {
+module.exports = (neutrino, tap) => {
   const tests = join(neutrino.options.tests, '**/*_test.js');
-    const sources = join(neutrino.options.source, '**/*.js');
+  const sources = join(neutrino.options.source, '**/*.js*');
   const defaults = {
     plugins: [
       require.resolve('karma-webpack'),
@@ -38,15 +37,20 @@ module.exports = (neutrino) => {
       ]
     }
   };
-    const karma = merge.all([
-      defaults,
-      neutrino.options.karma || {},
-      {
+
+  Object.assign(neutrino.options, {
+    karma: merge(defaults, neutrino.options.karma || {})
+  });
+
+  neutrino.on('test', ({ files, watch }) => {
+    const base = typeof tap === 'function' ?
+      tap(neutrino.options.karma) :
+      neutrino.options.karma;
+    const karma = merge(base, {
       singleRun: !watch,
       autoWatch: watch,
       webpack: neutrino.config.toConfig()
-      }
-    ]);
+    });
 
     delete karma.webpack.plugins;
 

packages/neutrino/bin/test.js

@@ -4,4 +4,8 @@ module.exports = (middleware, options) => test(middleware, options)
   .fork((err) => {
     console.error(err.stack || err);
     process.exit(1);
-  }, Function.prototype);
+  }, () => {
+    // Some test runners do not cleanly exit after resolving their promise.
+    // Force exit once we get here.
+    process.exit(0);
+  });