Fix IE11 support

While we don't really officially support IE, it would be nice if
_most_ non-complicated things actually worked.  Given where
transpilation is, and the fact that we already have webpack, this isn't
actually that riddiculous of an idea.

using babel was the intent with the original webpack stuff, but it turns out
babel-loader wasn't pulling in the babelrc properly when it was in the
root dir, so babel wasn't actually transpiling anything properly.

Functionally, this commit does 3 things:
1. Fixes the published Accepts header, as the ajax call confuses IE if
it doesn't have an encoding.
2. Includes core-js, to allow us to not really have to worry about
javascript features that aren't present in a given browser.
4. Includes the config to support all browsers with > 0.25% market
share, which should keep us compatible with most stuff.

Requires a patch to bmcweb for the updated charset header, as we didn't
handle that properly previously.
https://gerrit.openbmc-project.xyz/c/openbmc/bmcweb/+/24063

Tested:
Loaded the bmcweb patch.
Started the webui in IE11 with the console open.  Observed that webui
launches and logs in properly with no errors on the console.
Opened the webui in chrome to verify that nothing was broken.  Appears
working as it was before.

Measured the pre-rootfs size before and after this patchset.  It
adds 36KB to the final package size.  (404KB to 440KB).  For supporting
IE11 (and probably other browsers) I think this is well worth the cost.

Signed-off-by: Ed Tanous <ed.tanous@intel.com>
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
Change-Id: Ie402e3296deede466a7a05726ebd7a18bead0b80

1 files changed, 11 insertions, 2 deletions

diff --git a/webpack.config.js b/webpack.config.js
index b1c8808..be579cb 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -13,6 +13,10 @@ var path = require('path');
 var FilterChunkWebpackPlugin = require('filter-chunk-webpack-plugin');
 var MiniCssExtractPlugin = require('mini-css-extract-plugin');
 
+const isPathInside = require('is-path-inside')
+const pkgDir = require('pkg-dir')
+const coreJsDir = pkgDir.sync(require.resolve('core-js'))
+
 module.exports = (env, options) => {
   var isProd = options.mode === 'production';
 
@@ -71,8 +75,13 @@ module.exports = (env, options) => {
         // Transpile .js files using babel-loader
         // Compiles ES6 and ES7 into ES5 code
         test: /\.js$/,
-        use: 'babel-loader',
-        exclude: /node_modules/
+        exclude: (input) => isPathInside(input, coreJsDir),
+        use: {
+          loader: 'babel-loader',
+          options: {
+            presets: [['@babel/preset-env', {useBuiltIns: 'entry', corejs: 3}]]
+          }
+        }
       },
       {
         // ASSET LOADER