feat: support function for loader sunch as css-loader #58

example/webpack.config.js

@@ -12,6 +12,7 @@ module.exports = (env = {}) => {
     poolTimeout: env.watch ? Infinity : 2000,
   };
   const workerPoolSass = {
+    workerAllowedFunctions: ['cssLoaderGetLocalIdent'],
     workers: +env.threads,
     workerParallelJobs: 2,
     poolTimeout: env.watch ? Infinity : 2000,
@@ -50,6 +51,17 @@ module.exports = (env = {}) => {
               loader: path.resolve(__dirname, '../dist/index.js'),
               options: workerPoolSass,
             },
+            {
+              loader: 'css-loader',
+              options: {
+                modules: {
+                  getLocalIdent: function cssLoaderGetLocalIdent() {
+                    console.log('getLocalIdent called');
+                    return null;
+                  },
+                },
+              },
+            },
             'css-loader',
             'sass-loader',
           ].filter(Boolean),

src/WorkerPool.js

@@ -21,6 +21,7 @@ class PoolWorker {
     this.activeJobs = 0;
     this.onJobDone = onJobDone;
     this.id = workerId;
+    this.allowedFunctions = options.allowedFunctions;
 
     workerId += 1;
     // Empty or invalid node args would break the child process
@@ -106,9 +107,29 @@ class PoolWorker {
     });
   }
 
+  getReplacer() {
+    return (key, value) => {
+      if (
+        value instanceof Function &&
+        Array.isArray(this.allowedFunctions) &&
+        this.allowedFunctions.includes(value.name)
+      ) {
+        return {
+          __serialized_type: 'Function',
+          fnBody: value.toString(),
+          args: new Array(value.length).fill('a').map((i, dx) => `${i}${dx}`),
+        };
+      }
+      return replacer(key, value);
+    };
+  }
+
   writeJson(data) {
     const lengthBuffer = Buffer.alloc(4);
-    const messageBuffer = Buffer.from(JSON.stringify(data, replacer), 'utf-8');
+    const messageBuffer = Buffer.from(
+      JSON.stringify(data, this.getReplacer()),
+      'utf-8'
+    );
     lengthBuffer.writeInt32BE(messageBuffer.length, 0);
     this.writePipe.write(lengthBuffer);
     this.writePipe.write(messageBuffer);
@@ -323,6 +344,7 @@ export default class WorkerPool {
     this.poolTimeout = options.poolTimeout;
     this.workerNodeArgs = options.workerNodeArgs;
     this.workerParallelJobs = options.workerParallelJobs;
+    this.workerAllowedFunctions = options.workerAllowedFunctions;
     this.workers = new Set();
     this.activeJobs = 0;
     this.timeout = null;
@@ -389,6 +411,7 @@ export default class WorkerPool {
       {
         nodeArgs: this.workerNodeArgs,
         parallelJobs: this.workerParallelJobs,
+        allowedFunctions: this.workerAllowedFunctions,
       },
       () => this.onJobDone()
     );

src/serializer.js

@@ -15,6 +15,19 @@ export function reviver(_key, value) {
     if (value.__serialized_type === 'RegExp') {
       return new RegExp(value.source, value.flags);
     }
+    // eslint-disable-next-line no-underscore-dangle
+    else if (value.__serialized_type === 'Function') {
+      // eslint-disable-next-line no-new-func
+      return new Function(
+        ...value.args,
+        ` try {
+          return (${value.fnBody})(${value.args.join(',')})
+        } catch(err) {
+          console.error("[Invalid Function call]", err);
+        }
+        `
+      );
+    }
   }
 
   return value;

src/workerPools.js

@@ -22,6 +22,7 @@ function getPool(options) {
     poolTimeout: options.poolTimeout || 500,
     poolParallelJobs: options.poolParallelJobs || 200,
     poolRespawn: options.poolRespawn || false,
+    workerAllowedFunctions: options.workerAllowedFunctions || [],
   };
   const tpKey = JSON.stringify(workerPoolOptions);