Add mode logic to webpack config

Author: valentijnnieman

webpack.config.js

@@ -3,40 +3,61 @@ const packagejson = require('./package.json');
 
 const dashLibraryName = packagejson.name.replace(/-/g, '_');
 
-module.exports = (env, argv) => ({
-    entry: {main: './src/index.js'},
-    output: {
-        path: path.resolve(__dirname, dashLibraryName),
-        filename: argv.mode === 'development' ? `${dashLibraryName}.dev.js` : `${dashLibraryName}.min.js`,
-        library: dashLibraryName,
-        libraryTarget: 'window'
-    },
-    externals: {
-        react: 'React',
-        'react-dom': 'ReactDOM',
-        'plotly.js': 'Plotly'
-    },
-    module: {
-        rules: [
-            {
-                test: /\.js$/,
-                exclude: /node_modules/,
-                use: {
-                    loader: 'babel-loader'
-                }
-            },
-            {
-                test: /\.css$/,
-                use: [
-                    {
-                        loader: 'style-loader'
+module.exports = (env, argv) => {
+    let mode;
+
+    // if user specified mode flag take that value
+    if (argv && argv.mode) {
+        mode = argv.mode;
+    }
+
+    // else if configuration object is already set (module.exports) use that value
+    else if (module.exports && module.exports.mode) {
+        mode = module.exports = mode;
+    }
+
+    // else take webpack default
+    else {
+        mode = 'production';
+    }
+    return {
+        entry: {main: './src/index.js'},
+        output: {
+            path: path.resolve(__dirname, dashLibraryName),
+            filename:
+                mode === 'development'
+                    ? `${dashLibraryName}.dev.js`
+                    : `${dashLibraryName}.min.js`,
+            library: dashLibraryName,
+            libraryTarget: 'window',
+        },
+        externals: {
+            react: 'React',
+            'react-dom': 'ReactDOM',
+            'plotly.js': 'Plotly',
+        },
+        module: {
+            rules: [
+                {
+                    test: /\.js$/,
+                    exclude: /node_modules/,
+                    use: {
+                        loader: 'babel-loader',
                     },
-                    {
-                        loader: 'css-loader'
-                    }
-                ]
-            }
-        ]
-    },
-    devtool: argv.mode === 'development' ? 'eval-source-map' : 'none'
-});
+                },
+                {
+                    test: /\.css$/,
+                    use: [
+                        {
+                            loader: 'style-loader',
+                        },
+                        {
+                            loader: 'css-loader',
+                        },
+                    ],
+                },
+            ],
+        },
+        devtool: mode === 'development' ? 'eval-source-map' : 'none',
+    };
+};