From 7dbaa043b6fd3160f09b72d8bfaa9d0000015e47 Mon Sep 17 00:00:00 2001
From: Dan Egnor <egnor@ofb.net>
Date: Wed, 19 Nov 2025 01:49:36 -0800
Subject: [PATCH] fix a few problems with output-file obfuscation

---
 esbuild-plugin-obfuscator.js | 64 +++++++++++++++++++++++++++++-------
 1 file changed, 52 insertions(+), 12 deletions(-)

diff --git a/esbuild-plugin-obfuscator.js b/esbuild-plugin-obfuscator.js
index 172cbfe..ef5d0ab 100644
--- a/esbuild-plugin-obfuscator.js
+++ b/esbuild-plugin-obfuscator.js
@@ -2,6 +2,9 @@ import JavaScriptObfuscator from 'javascript-obfuscator';
 import micromatch from 'micromatch';
 import { promises as fs } from 'fs';
 import { getBuildExtensions } from 'esbuild-extra';
+import path from 'node:path';
+
+const pluginName = 'obfuscator';
 
 export function ObfuscatorPlugin({
   filter = [],
@@ -9,57 +12,87 @@ export function ObfuscatorPlugin({
   shouldWriteOutputSourceMap = false,
   shouldGenerateSourceMap = false,
   ignoreRequireImports = true,
+  debug = false,
   ...options
 } = {}) {
   return {
-    name: 'obfuscator',
+    name: pluginName,
+
     async setup(build) {
       const { onTransform } = getBuildExtensions(build, 'obfuscator');
-      
+
       options = {
         ignoreRequireImports,
         ...options,
       };
 
       if (shouldObfuscateOutput) {
+        // Work around esbuild issue by deferring file writes.
+        // See: https://github.com/evanw/esbuild/issues/2999
+        const writeFlag = build.initialOptions.write;
         build.initialOptions.write = false;
 
         build.onEnd(async (result) => {
-          let tasks = [];
+          const outputData = {};
 
           for (const output of result.outputFiles) {
             const filePath = output.path;
 
             const originalCode = output.text;
 
+            // Use micromatch to check if the OUTPUT file matches any patterns in the filter array
+            const shouldObfuscate = micromatch.isMatch(filePath, filter);
+            if (!shouldObfuscate) {
+              outputData[filePath] = output.contents;
+              continue;
+            }
+
             // Obfuscate the code using javascript-obfuscator with conditional sourcemap generation
             const obfuscatorOptions = {
               ...options,
               sourceMap: shouldWriteOutputSourceMap
             };
-            
+
             if (shouldWriteOutputSourceMap) {
               obfuscatorOptions.sourceMapFileName = filePath + '.map';
             }
-            
+
+
             const obfuscationResult = JavaScriptObfuscator.obfuscate(originalCode, obfuscatorOptions);
 
             const obfuscatedCode = obfuscationResult.getObfuscatedCode();
+            output.contents = new TextEncoder().encode(obfuscatedCode);
 
             // Write the obfuscated code to the file
-            tasks.push(fs.writeFile(filePath, obfuscatedCode));
-            
+            outputData[filePath] = obfuscatedCode;
+
             if (shouldWriteOutputSourceMap) {
               const sourceMap = obfuscationResult.getSourceMap();
               // Write the sourcemap file
-              tasks.push(fs.writeFile(filePath + '.map', sourceMap));
+              outputData[obfuscatorOptions.sourceMapFileName] = sourceMap;
+            }
+
+            if (debug) {
+              const shortPath = build.initialOptions.outdir
+                ? path.relative(build.initialOptions.outdir, filePath)
+                : path.basename(filePath);
+              console.log(
+                `[${pluginName}] processed: ${shortPath} ` +
+                `(${originalCode.length}b => ${obfuscatedCode.length}b)`
+              );
             }
           }
 
-          await Promise.all(tasks);
+          // Write modified data if file writing was originally enabled.
+          if (writeFlag === undefined || writeFlag) {
+            await Promise.all(Object.entries(outputData).map(async ([p, c]) => {
+              await fs.mkdir(path.dirname(p), { recursive: true });
+              await fs.writeFile(p, c);
+            }));
+          }
         });
       } else {
-        onTransform({ 
+        onTransform({
           loaders: ['js'],
           namespace: 'file'
         }, async (args) => {
@@ -76,15 +109,22 @@ export function ObfuscatorPlugin({
             ...options,
             sourceMap: shouldGenerateSourceMap
           };
-          
+
           if (shouldGenerateSourceMap) {
             obfuscatorOptions.sourceMapFileName = args.path + '.map';
           }
-          
+
           const obfuscationResult = JavaScriptObfuscator.obfuscate(args.code, obfuscatorOptions);
 
           const obfuscatedCode = obfuscationResult.getObfuscatedCode();
 
+          if (debug) {
+            console.log(
+              `[${pluginName}] processed: ${filePath} ` +
+              `(${args.code.length}b => ${obfuscatedCode.length}b)`
+            );
+          }
+
           if (shouldGenerateSourceMap) {
             let sourceMap = obfuscationResult.getSourceMap();
             sourceMap = JSON.parse(sourceMap);