From 726faaa1e6eeb96f6c6b223d1ba925f9d7f33cba Mon Sep 17 00:00:00 2001
From: Floriel <Ffloriel@users.noreply.github.com>
Date: Thu, 24 Feb 2022 22:09:01 +0000
Subject: [PATCH] feat(purgecss-webpack-plugin): load config file automatically
 #767

---
 .../__tests__/cases/simple/purgecss.config.js | 22 +++++++++++++++++++
 .../__tests__/cases/simple/webpack.config.js  | 22 +------------------
 packages/purgecss-webpack-plugin/src/index.ts | 16 ++++++++++++--
 3 files changed, 37 insertions(+), 23 deletions(-)
 create mode 100644 packages/purgecss-webpack-plugin/__tests__/cases/simple/purgecss.config.js

diff --git a/packages/purgecss-webpack-plugin/__tests__/cases/simple/purgecss.config.js b/packages/purgecss-webpack-plugin/__tests__/cases/simple/purgecss.config.js
new file mode 100644
index 00000000..3e625883
--- /dev/null
+++ b/packages/purgecss-webpack-plugin/__tests__/cases/simple/purgecss.config.js
@@ -0,0 +1,22 @@
+const path = require("path");
+const glob = require("glob");
+
+const customExtractor = (content) => {
+  const res = content.match(/[A-z0-9-:/]+/g) || [];
+  return res;
+};
+
+const PATHS = {
+  src: path.join(__dirname, "src"),
+};
+
+module.exports = {
+  paths: glob.sync(`${PATHS.src}/*`),
+  safelist: ["safelisted"],
+  extractors: [
+    {
+      extractor: customExtractor,
+      extensions: ["html", "js"],
+    },
+  ],
+}
\ No newline at end of file
diff --git a/packages/purgecss-webpack-plugin/__tests__/cases/simple/webpack.config.js b/packages/purgecss-webpack-plugin/__tests__/cases/simple/webpack.config.js
index fbf654c3..c1eefaad 100644
--- a/packages/purgecss-webpack-plugin/__tests__/cases/simple/webpack.config.js
+++ b/packages/purgecss-webpack-plugin/__tests__/cases/simple/webpack.config.js
@@ -1,17 +1,6 @@
-const path = require("path");
-const glob = require("glob");
 const MiniCssExtractPlugin = require("mini-css-extract-plugin");
 const { PurgeCSSPlugin } = require("../../../src/");
 
-const customExtractor = (content) => {
-  const res = content.match(/[A-z0-9-:/]+/g) || [];
-  return res;
-};
-
-const PATHS = {
-  src: path.join(__dirname, "src"),
-};
-
 module.exports = {
   mode: "development",
   devtool: "source-map",
@@ -41,15 +30,6 @@ module.exports = {
     new MiniCssExtractPlugin({
       filename: "[name].css",
     }),
-    new PurgeCSSPlugin({
-      paths: glob.sync(`${PATHS.src}/*`),
-      safelist: ["safelisted"],
-      extractors: [
-        {
-          extractor: customExtractor,
-          extensions: ["html", "js"],
-        },
-      ],
-    }),
+    new PurgeCSSPlugin({}),
   ],
 };
diff --git a/packages/purgecss-webpack-plugin/src/index.ts b/packages/purgecss-webpack-plugin/src/index.ts
index e4fca315..efccb900 100644
--- a/packages/purgecss-webpack-plugin/src/index.ts
+++ b/packages/purgecss-webpack-plugin/src/index.ts
@@ -2,9 +2,9 @@ import * as fs from "fs";
 import * as path from "path";
 import {
   PurgeCSS,
-  defaultOptions,
   ResultPurge,
   UserDefinedOptions as PurgeCSSUserDefinedOptions,
+  defaultOptions,
 } from "purgecss";
 import { Compilation, Compiler, sources } from "webpack";
 import { PurgedStats, UserDefinedOptions } from "./types";
@@ -128,7 +128,19 @@ export class PurgeCSSPlugin {
   }
 
   initializePlugin(compilation: Compilation): void {
-    compilation.hooks.additionalAssets.tapPromise(pluginName, () => {
+    compilation.hooks.additionalAssets.tapPromise(pluginName, async () => {
+      let configFileOptions: UserDefinedOptions | undefined;
+      try {
+        const t = path.resolve(process.cwd(), "purgecss.config.js");
+        configFileOptions = await import(t);
+      } catch {
+        // no config file present
+      }
+      this.options = {
+        ...(configFileOptions ? configFileOptions : {}),
+        ...this.options,
+      };
+
       const entryPaths =
         typeof this.options.paths === "function"
           ? this.options.paths()