Re-bundle karma test files when non-test JS files change.

Not sure there is a better way to do this, but apparently karma only watches the test files themselves which is not really what one wants during test driven development or really ever.

Fixes ampproject#1623

gulpfile.js

@@ -31,6 +31,7 @@ var rename = require('gulp-rename');
 var replace = require('gulp-replace');
 var source = require('vinyl-source-stream');
 var sourcemaps = require('gulp-sourcemaps');
+var touch = require('touch')
 var uglify = require('gulp-uglify');
 var util = require('gulp-util');
 var watchify = require('watchify');
@@ -443,6 +444,10 @@ function compileJs(srcDir, srcFilename, destDir, options) {
     bundler.on('update', function() {
       console.log('-> bundling ' + srcDir + '...');
       rebundle();
+      // Touch file in unit test set. This triggers rebundling of tests because
+      // karma only considers changes to tests files themselves re-bundle
+      // worthy.
+      touch('test/_init_tests.js');
     });
   }
 

package.json

@@ -41,7 +41,7 @@
     "finalhandler": "0.4.0",
     "fs-extra": "0.26.4",
     "gulp": "3.9.0",
-    "gulp-closure-compiler": "^0.4.0",
+    "gulp-closure-compiler": "0.4.0",
     "gulp-eslint": "1.1.0",
     "gulp-exec": "2.1.2",
     "gulp-file": "0.2.0",
@@ -72,7 +72,7 @@
     "karma-sauce-launcher": "0.2.14",
     "karma-sinon-chai": "1.0.0",
     "lazypipe": "1.0.1",
-    "lolex": "^1.4.0",
+    "lolex": "1.4.0",
     "minimist": "1.2.0",
     "mocha": "2.3.3",
     "path": "0.12.7",
@@ -85,6 +85,7 @@
     "sinon-chai": "2.8.0",
     "text-table": "0.2.0",
     "through2": "2.0.0",
+    "touch": "1.0.0",
     "vinyl-buffer": "1.0.0",
     "vinyl-source-stream": "1.1.0",
     "watchify": "3.6.0"