From c21eccc57e7852ec3fcbeb3a4438cd32f58b1a63 Mon Sep 17 00:00:00 2001
From: Slava Leleka <v.leleka@adguard.com>
Date: Wed, 10 May 2023 20:37:37 +0300
Subject: [PATCH] improve responseType checking condition

---
 src/scriptlets/prevent-fetch.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/scriptlets/prevent-fetch.js b/src/scriptlets/prevent-fetch.js
index d00873c6..b9f2277f 100644
--- a/src/scriptlets/prevent-fetch.js
+++ b/src/scriptlets/prevent-fetch.js
@@ -116,10 +116,18 @@ export function preventFetch(source, propsToMatch, responseBody = 'emptyObj', re
         return;
     }
 
+    const isResponseTypeSpecified = typeof responseType !== 'undefined';
+    const isResponseTypeSupported = (responseType) => {
+        const SUPPORTED_TYPES = [
+            'default',
+            'opaque',
+        ];
+        return SUPPORTED_TYPES.includes(responseType);
+    };
     // Skip disallowed response types,
     // specified responseType has limited list of possible values
-    if (typeof responseType !== 'undefined'
-        && !(responseType === 'default' || responseType === 'opaque')) {
+    if (isResponseTypeSpecified
+        && !isResponseTypeSupported(responseType)) {
         logMessage(source, `Invalid responseType parameter: '${responseType}'`);
         return;
     }