functions for whitelist and whitelistPatterns

Author: SebastianS90

README.md

@@ -95,6 +95,27 @@ new PurgecssPlugin({
 })
 ```
 
+* #### whitelist and whitelistPatterns
+
+Similar as for the `paths` option, you also can define functions for the these options:
+
+```js
+function collectWhitelist() {
+    // do something to collect the whitelist
+    return ['whitelisted'];
+}
+function collectWhitelistPatterns() {
+    // do something to collect the whitelist
+    return [/^whitelisted-/];
+}
+
+// In the webpack configuration
+new PurgecssPlugin({
+  whitelist: collectWhitelist,
+  whitelistPatterns: collectWhitelistPatterns
+})
+```
+
 ## Contributing
 
 Please read [CONTRIBUTING.md](./.github/CONTRIBUTING.md) for details on our code of conduct, and the process for submitting pull requests to us.

__tests__/__snapshots__/webpack-integration.test.js.snap

@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`Webpack Integration Tests simple 1`] = `
+exports[`Webpack Integration Tests path-and-whitelist-functions 1`] = `
 ".hello {
   color: red;
 }
@@ -15,7 +15,7 @@ md\\\\:w-2\\\\/3 {
 "
 `;
 
-exports[`Webpack Integration Tests simple-with-exclusion 1`] = `
+exports[`Webpack Integration Tests simple 1`] = `
 ".hello {
   color: red;
 }
@@ -30,31 +30,31 @@ md\\\\:w-2\\\\/3 {
 "
 `;
 
-exports[`Webpack Integration Tests simple-with-exclusion 2`] = `
-".legacy-unused-class {
+exports[`Webpack Integration Tests simple-with-exclusion 1`] = `
+".hello {
   color: red;
 }
 
-.unused-too {
-  color: blue;
+.whitelisted {
+  color: green;
 }
 
-.hello {
+md\\\\:w-2\\\\/3 {
   color: red;
 }
 "
 `;
 
-exports[`Webpack Integration Tests simple-with-paths-function 1`] = `
-".hello {
+exports[`Webpack Integration Tests simple-with-exclusion 2`] = `
+".legacy-unused-class {
   color: red;
 }
 
-.whitelisted {
-  color: green;
+.unused-too {
+  color: blue;
 }
 
-md\\\\:w-2\\\\/3 {
+.hello {
   color: red;
 }
 "

__tests__/cases/simple-with-paths-function/expected/style.css renamed to __tests__/cases/path-and-whitelist-functions/expected/style.css

@@ -29,7 +29,7 @@ module.exports = {
     new ExtractTextPlugin('style.css'),
     new PurgecssPlugin({
       paths: () => glob.sync(`${PATHS.src}/*`),
-      whitelist: ['whitelisted'],
+      whitelist: () => ['whitelisted'],
       extractors: [
         {
           extractor: CustomExtractor,

__tests__/cases/simple-with-paths-function/src/content.html renamed to __tests__/cases/path-and-whitelist-functions/src/content.html

@@ -55,12 +55,19 @@ export default class PurgecssPlugin {
 
             // Compile through Purgecss and attach to output.
             // This loses sourcemaps should there be any!
-            const purgecss = new Purgecss({
+            const options = {
               ...this.options,
               content: filesToSearch,
               css: [asset.source()],
               stdin: true
-            })
+            };
+            if (typeof options.whitelist === 'function') {
+              options.whitelist = options.whitelist();
+            }
+            if (typeof options.whitelistPatterns === 'function') {
+              options.whitelistPatterns = options.whitelistPatterns();
+            }
+            const purgecss = new Purgecss(options);
             compilation.assets[name] = new ConcatSource(purgecss.purge()[0].css)
           })
         })