Add source-map-loader to webpack config

This makes source maps work in the demo

package.json

@@ -35,6 +35,7 @@
     "npm-run-all": "^4.1.2",
     "nyc": "^11.8.0",
     "sorcery": "^0.10.0",
+    "source-map-loader": "^0.2.3",
     "tslint": "^5.9.1",
     "tslint-consistent-codestyle": "^1.13.0",
     "typescript": "2.8.3",

webpack.config.js

@@ -6,5 +6,14 @@ module.exports = {
     path: path.resolve(__dirname, 'demo/dist'),
     filename: 'bundle.js'
   },
-  devtool: 'source-map'
+  devtool: 'source-map',
+  module: {
+    rules: [
+      {
+        test: /\.js$/,
+        use: ["source-map-loader"],
+        enforce: "pre"
+      }
+    ]
+  }
 };

yarn.lock

@@ -346,7 +346,7 @@ async@^1.4.0:
   version "1.5.2"
   resolved "https://registry.yarnpkg.com/async/-/async-1.5.2.tgz#ec6a61ae56480c0c3cb241c95618e20892f9672a"
 
-async@^2.1.2:
+async@^2.1.2, async@^2.5.0:
   version "2.6.1"
   resolved "https://registry.yarnpkg.com/async/-/async-2.6.1.tgz#b245a23ca71930044ec53fa46aa00a3e87c6a610"
   dependencies:
@@ -3147,6 +3147,15 @@ loader-utils@^1.1.0:
     emojis-list "^2.0.0"
     json5 "^0.5.0"
 
+loader-utils@~0.2.2:
+  version "0.2.17"
+  resolved "https://registry.yarnpkg.com/loader-utils/-/loader-utils-0.2.17.tgz#f86e6374d43205a6e6c60e9196f17c0299bfb348"
+  dependencies:
+    big.js "^3.1.3"
+    emojis-list "^2.0.0"
+    json5 "^0.5.0"
+    object-assign "^4.0.1"
+
 locate-path@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/locate-path/-/locate-path-2.0.0.tgz#2b568b265eec944c6d9c0de9c3dbbbca0354cd8e"
@@ -4883,6 +4892,14 @@ source-list-map@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/source-list-map/-/source-list-map-2.0.0.tgz#aaa47403f7b245a92fbc97ea08f250d6087ed085"
 
+source-map-loader@^0.2.3:
+  version "0.2.3"
+  resolved "https://registry.yarnpkg.com/source-map-loader/-/source-map-loader-0.2.3.tgz#d4b0c8cd47d54edce3e6bfa0f523f452b5b0e521"
+  dependencies:
+    async "^2.5.0"
+    loader-utils "~0.2.2"
+    source-map "~0.6.1"
+
 source-map-resolve@^0.5.0, source-map-resolve@^0.5.1:
   version "0.5.2"
   resolved "https://registry.yarnpkg.com/source-map-resolve/-/source-map-resolve-0.5.2.tgz#72e2cc34095543e43b2c62b2c4c10d4a9054f259"