Reduce and simplify loader

Author: Alexander Grigoriev

index.js

@@ -5,56 +5,59 @@ const loaderUtils = require('loader-utils');
 
 /** @type {import('webpack').loader.Loader} */
 module.exports = function(content) {
-  this.cacheable();
+  this.cacheable && this.cacheable();
+
+  const options = loaderUtils.getOptions(this) || {};
   const callback = this.async();
-  const options = loaderUtils.getOptions(this);
-  genTypings(this.resourcePath, content, options, callback);
-};
 
-/**
- * @param {string} [path]
- * @param {string | Buffer} [content]
- * @param {import('loader-utils').OptionObject} [options]
- * @param {import('webpack').loader.loaderCallback} [callback]
- */
-function genTypings(path, content, options, callback) {
-  if (Buffer.isBuffer(content)) {
-    content = content.toString('utf8');
-  }
+  let typings = '';
 
-  /** @type {string[]} */
-  let classes = [];
-  {
-    /** @type {RegExpExecArray} */
-    let match;
-    while (match = classesRegex.exec(content)) {
-      if (classes.indexOf(match[1]) === -1) {
-        classes.push(match[1]);
-      }
-    }
+  if (options.banner) {
+    typings = `${options.banner}\n`;
   }
 
-  let typings = '';
   {
-    if (options.banner) {
-      typings = `${options.banner}\n`;
-    }
+    let classes = getClasses(content);
+
     if (options.namedExport) {
       for (let c of classes) {
         typings += `export const ${c}: string;\n`;
       }
     } else {
-      const name = getInterfaceName(path);
-      typings += `export interface ${name} {\n`;
+      const i = getInterfaceName(this.resourcePath);
+      typings += `export interface ${i} {\n`;
       for (let c of classes) {
         typings += `  '${c}': string\n`;
       }
-      typings += `}\ndeclare const styles: ${name};\nexport default styles;\n`;
+      typings += `}\ndeclare const styles: ${i};\nexport default styles;\n`;
     }
   }
-  writeFile(getDtsPath(path), typings);
+
+  fs.writeFileSync(getDtsPath(this.resourcePath), typings);
 
   callback(null, content);
+};
+
+/**
+ * @param {string | Buffer} [content]
+ */
+function getClasses(content) {
+  if (Buffer.isBuffer(content)) {
+    content = content.toString('utf8');
+  }
+
+  /** @type {string[]} */
+  let classes = [];
+
+  /** @type {RegExpExecArray} */
+  let match;
+  while (match = classesRegex.exec(content)) {
+    if (classes.indexOf(match[1]) === -1) {
+      classes.push(match[1]);
+    }
+  }
+
+  return classes;
 }
 
 const classesRegex = /"([^"\\]+)":/g;
@@ -74,13 +77,3 @@ function getInterfaceName(path) {
     .replace(/^(\w)/, (_, c) => 'I' + c.toUpperCase())
     .replace(/\W+(\w)/g, (_, c) => c.toUpperCase());
 }
-
-/**
- * @param {string} [path]
- * @param {string} [content]
- */
-function writeFile(path, content) {
-  if (!fs.existsSync(path) || fs.readFileSync(path).toString('utf8') !== content) {
-    fs.writeFileSync(path, content);
-  }
-}

package.json

@@ -7,6 +7,6 @@
     "loader-utils": "^1.2.0"
   },
   "peerDependencies": {
-    "css-loader": "2.0.2"
+    "css-loader": "^2.0.2"
   }
 }