feat: Add environment variable options to external files

README.md

@@ -79,6 +79,15 @@ import { newInjectedPage } from 'fingerprint-injector';
 })();
 ```
 
+## Environment Variables
+
+The following environment variables can be used to customize file paths used by the fingerprinting tools:
+
+- `FINGERPRINT_NETWORK_DEFINITION_PATH`: Custom path to the fingerprint network definition zip file. If not set, defaults to the bundled file in `fingerprint-generator`. The default file can be found at `fingerprint-generator/data_files/fingerprint-network-definition.zip`.
+- `FINGERPRINT_INJECTOR_UTILS_PATH`: Custom path to the fingerprint injector utils.js file. If not set, defaults to the bundled file in `fingerprint-injector`. The default file can be found at `fingerprint-injector/utils.js`.
+
+You can copy these files to custom locations and provide their paths via these environment variables if needed.
+
 ## Support
 
 If you find any bug or issue with any of the fingerprinting tools, please [submit an issue on GitHub](https://github.com/apify/fingerprint-suite/issues).

packages/fingerprint-generator/src/fingerprint-generator.ts

@@ -141,7 +141,7 @@ export class FingerprintGenerator extends HeaderGenerator {
             slim: options.slim,
         };
         this.fingerprintGeneratorNetwork = new BayesianNetwork({
-            path: `${__dirname}/data_files/fingerprint-network-definition.zip`,
+            path: process.env.FINGERPRINT_NETWORK_DEFINITION_PATH || `${__dirname}/data_files/fingerprint-network-definition.zip`,
         });
     }
 

packages/fingerprint-injector/src/fingerprint-injector.ts

@@ -1,4 +1,4 @@
-import { readFileSync } from 'fs';
+import { readFileSync, existsSync } from 'fs';
 
 import {
     BrowserFingerprintWithHeaders,
@@ -310,8 +310,12 @@ export class FingerprintInjector {
      * causing errors when executing it in the browser.
      */
     private _loadUtils(): string {
+        const path = process.env.FINGERPRINT_INJECTOR_UTILS_PATH || `${__dirname}/utils.js`
+        if (!existsSync(path)) {
+            throw new Error(`Unable to find ${path}`);
+        }
         // path.join would be better here, but Vercel's build system doesn't like it (https://github.com/apify/fingerprint-suite/issues/135)
-        const utilsJs = readFileSync(`${__dirname}/utils.js`);
+        const utilsJs = readFileSync(path);
         return `\n${utilsJs}\n`;
     }
 

packages/generative-bayesian-network/src/bayesian-network.ts

@@ -1,4 +1,5 @@
 import AdmZip = require('adm-zip');
+import { existsSync } from 'fs';
 
 import { BayesianNode } from './bayesian-node';
 
@@ -13,6 +14,9 @@ export class BayesianNetwork {
     private nodesByName: Record<string, BayesianNode> = {};
 
     constructor({ path }: { path: string }) {
+        if (!existsSync(path)) {
+            throw new Error(`Unable to find ${path}`);
+        }
         const zip = new AdmZip(path);
         const zipEntries = zip.getEntries();