perf: update to support dir looping

This commit adds default repo support for looping through all CSS files
within a ./src dir for postCSS scripting.

The legacy single-file static process is maintained if a developer
wishes this for their element.

Changes to be committed:
modified:   template/scripts/postCss.mjs

template/scripts/postCss.mjs

@@ -1,18 +1,62 @@
 import autoprefixer from 'autoprefixer';
 import postcss from 'postcss';
 import comments from 'postcss-discard-comments';
+import path from 'path';
 import fs from 'fs';
+const __dirname = new URL('.', import.meta.url).pathname;
+const directoryPath = path.join(__dirname, '../src');
 
-fs.readFile('src/style.css', (err, css) => {
-  postcss([autoprefixer, comments])
-    .use(comments({
-      remove: function(comment) { return comment[0] == "@"; }
-    }))
-    .process(css, { from: 'src/style.css', to: 'src/style.css' })
-    .then(result => {
-      fs.writeFile('src/style.css', result.css, () => true)
-      if ( result.map ) {
-        fs.writeFile('src/style.map', result.map, () => true)
-      }
-    })
+/**
+ * Default postCSS run
+ * Locates all CSS files within the directory and loop
+ * through the standardProcessor() function.
+ */
+fs.readdir(directoryPath, function (err, files) {
+  //handling error
+  if (err) {
+      return console.log('Unable to scan directory: ' + err);
+  }
+  //listing all files using forEach
+  files.forEach(function (file) {
+    if (file.includes(".css")) {
+      standardProcessor(file);
+    }
+  });
 });
+
+/**
+ * The standardProcessor function applies tokens for fallback selectors
+ * and completes a post cleanup.
+ * @param {string} file
+ */
+function standardProcessor(file) {
+ fs.readFile(`src/${file}`, (err, css) => {
+   postcss([autoprefixer, comments])
+   .use(comments({
+     remove: function(comment) { return comment[0] == "@"; }
+   }))
+   .process(css, { from: `src/${file}`, to: `src/${file}` })
+   .then(result => {
+     fs.writeFile(`src/${file}`, result.css, () => true)
+   })
+ });
+}
+
+/**
+ * ALTERNATE script:
+ * The following is a static builder for rendering one
+ * CSS file at a time if that is required.
+ */
+// fs.readFile('src/style.css', (err, css) => {
+//   postcss([autoprefixer, comments])
+//     .use(comments({
+//       remove: function(comment) { return comment[0] == "@"; }
+//     }))
+//     .process(css, { from: 'src/style.css', to: 'src/style.css' })
+//     .then(result => {
+//       fs.writeFile('src/style.css', result.css, () => true)
+//       if ( result.map ) {
+//         fs.writeFile('src/style.map', result.map, () => true)
+//       }
+//     })
+// });