net: add net.BlockList.isBlockList(value)

jasnell · ruyadorno · commit ed7eab1421b0 · 2025-01-05T12:57:35.000-05:00
PR-URL: #56078 Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: theanarkh <theratliter@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
diff --git a/doc/api/net.md b/doc/api/net.md
@@ -170,6 +170,15 @@ added:
 
 The list of rules added to the blocklist.
 
+### `BlockList.isBlockList(value)`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* `value` {any} Any JS value
+* Returns `true` if the `value` is a `net.BlockList`.
+
 ## Class: `net.SocketAddress`
 
 <!-- YAML
diff --git a/lib/internal/blocklist.js b/lib/internal/blocklist.js
@@ -43,6 +43,15 @@ class BlockList {
     this[kHandle][owner_symbol] = this;
   }
 
+  /**
+   * Returns true if the value is a BlockList
+   * @param {any} value
+   * @returns {boolean}
+   */
+  static isBlockList(value) {
+    return value?.[kHandle] !== undefined;
+  }
+
   [kInspect](depth, options) {
     if (depth < 0)
       return this;
diff --git a/test/parallel/test-blocklist.js b/test/parallel/test-blocklist.js
@@ -282,3 +282,8 @@ const util = require('util');
   assert(!blocklist.check('1.1.1.2'));
   assert(!blocklist.check('2.3.4.5'));
 }
+
+{
+  assert(BlockList.isBlockList(new BlockList()));
+  assert(!BlockList.isBlockList({}));
+}
