Use babel 6 and move where babel-polyfills are added.

Babel 7 is still pending official release and causes some issues.  Babel
7.0.0-rc.2 throws errors where 7.0.0-rc.1 does not.  Rather than figure
out what causes these, I recommend we wait until it is officially
released.  The main benefit of Babel 7 is that the polyfills can be
added conditionally based on actual use.

When adding babel-polyfill to src/index.js, the coverage for index.js is
wrong (the line numbers are incorrect).  Further, babel-polyfill is
fairly heavy, so just add it to the vendor.js (geo.js not geo.lean.js).
It also needs to be added to the test-utils to ensure that we can use
new language features in the tests with PhantomJS.  Reference to
babel-polyfill has been moved to src/polyfills.js, and that file has
been excluded from coverage analysis.

For the coverage reporters, disable the html reporter as it fails with
karma-coverage and babel.  One solution would be to switch to
karma-coverage-istanbul-reporter, but I don't think the html coverage is
strictly necessary as we use codecov.

karma-cov.conf.js

@@ -34,16 +34,17 @@ module.exports = function (config) {
   karma_config.specReporter = {suppressPassed: true, suppressSkipped: true};
   karma_config.coverageReporter = {
     reporters: [
-      {type: 'html', dir: 'dist/coverage/', subdir: subdir_name},
+      // {type: 'html', dir: 'dist/coverage/', subdir: subdir_name},
       {type: 'cobertura', dir: 'dist/cobertura/', file: 'coverage.xml', subdir: subdir_name},
       {type: 'json', dir: 'dist/coverage/json/', subdir: subdir_name},
-      {type: 'lcovonly', dir: 'lcov', subdir: subdir_name},
+      {type: 'lcovonly', dir: 'dist/coverage/lcov', subdir: subdir_name},
       {type: 'text'}
     ]
   };
   karma_config.webpack.module.rules.unshift({
     test: /\.js$/,
     include: path.resolve('src/'),
+    exclude: path.resolve('src/polyfills.js'),
     use: ['istanbul-instrumenter-loader']
   });
 

package.json

@@ -28,10 +28,11 @@
     "hammerjs": "^2.0.8"
   },
   "devDependencies": {
-    "@babel/core": "^7.0.0-rc.1",
-    "@babel/polyfill": "^7.0.0-rc.1",
-    "@babel/preset-env": "^7.0.0-rc.1",
-    "babel-loader": "^8.0.0-beta.4",
+    "babel-core": "^6.26.0",
+    "babel-loader": "^7.1.5",
+    "babel-plugin-istanbul": "^4.1.6",
+    "babel-polyfill": "^6.26.0",
+    "babel-preset-env": "^1.7.0",
     "body-parser": "^1.15.0",
     "bootstrap": "^3.3.6",
     "bootswatch": "^3.3.6",

src/polyfills.js

@@ -0,0 +1 @@
+require('babel-polyfill');

src/vendor.js

@@ -4,6 +4,9 @@
  * @copyright 2010-2016, Michael Bostock
  * @license BSD-3-Clause
  */
+
+require('./polyfills');
+
 var globals = {
   d3: require('d3'),
   hammerjs: require('hammerjs')

tests/test-common.js

@@ -1,7 +1,7 @@
 // General utilities that are made available to tests.
 
 var $ = require('jquery');
-var geo = require('../src');
+var geo = require('./test-utils').geo;
 
 module.exports = {
   createOsmMap: function (mapOpts, osmOpts, notiles) {

tests/test-utils.js

@@ -4,6 +4,7 @@
 
 var $ = require('jquery');
 
+require('../src/polyfills');
 var geo = require('../src');
 var bowser = require('bowser');
 

webpack.base.config.js

@@ -86,14 +86,15 @@ module.exports = {
         loader: 'babel-loader',
         options: {
           presets: [[
-            '@babel/preset-env', {
+            'env', {
               targets: {
-                browsers: ['defaults']
+                browsers: ['defaults'],
+                uglify: true
               },
-              forceAllTransforms: true,
               useBuiltIns: 'usage'
             }
-          ]]
+          ]],
+          cacheDirectory: true
         }
       }]
     }, {

webpack.config.js

@@ -3,7 +3,7 @@ var merge = require('webpack-merge');
 
 module.exports = merge(config, {
   entry: {
-    'geo': './index.js',
-    'geo.min': './index.js'
+    'geo': ['./polyfills', './index.js'],
+    'geo.min': ['./polyfills', './index.js']
   }
 });