feat: support postcss loader options config and auto set sourceMap:true when devtool set

Author: hubcarl

lib/base.js

@@ -336,7 +336,8 @@ class WebpackBaseBuilder extends Config {
       if (Array.isArray(itemLoader.use)) {
         if (itemLoader.postcss) {
           const postcssIndex = ['css', 'css_module'].includes(name) ? itemLoader.use.length : itemLoader.use.length - 1;
-          itemLoader.use.splice(postcssIndex, 0, 'postcss-loader');
+          const postcssLoader = this.createPostCssLoader(loaderOptions && loaderOptions.postcss);
+          itemLoader.use.splice(postcssIndex, 0, postcssLoader);
         }
         itemLoader.use.forEach((loader, index) => {
           const label = this.utils.getLoaderLabel(loader);
@@ -577,6 +578,11 @@ class WebpackBaseBuilder extends Config {
     this.styleLoader = { loader, options };
   }
 
+  createPostCssLoader(loaderOptions) {
+    const options = this.merge(this.config.devtool ? { sourceMap: true } : {}, loaderOptions);
+    return { loader: 'postcss-loader', options };
+  }
+
   createDllPlugin(dll) {
     dll = dll || this.config.dll;
     const dllArray = WebpackBaseBuilder.getDllConfig(dll);