From 016b51d608838d39c3e52c5c3a33b1c5be0617e8 Mon Sep 17 00:00:00 2001
From: John Leidegren <john@tessin.se>
Date: Thu, 28 Nov 2019 08:50:03 +0100
Subject: [PATCH] Added support for hashing symbols

---
 __tests__/hash.ts | 2 ++
 src/Hash.js       | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/__tests__/hash.ts b/__tests__/hash.ts
index 5c2b0ebad1..0408a30111 100644
--- a/__tests__/hash.ts
+++ b/__tests__/hash.ts
@@ -22,6 +22,8 @@ describe('hash', () => {
     expect(hash('a')).toBe(97);
     expect(hash('immutable-js')).toBe(510203252);
     expect(hash(123)).toBe(123);
+    expect(hash(Symbol('a-js'))).toBe(97);
+    expect(hash(Symbol('immutable-js'))).toBe(510203252);
   });
 
   it('generates different hashes for decimal values', () => {
diff --git a/src/Hash.js b/src/Hash.js
index f15466ffb9..a6b68bb2e6 100644
--- a/src/Hash.js
+++ b/src/Hash.js
@@ -22,6 +22,13 @@ export function hash(o) {
       return o.length > STRING_HASH_CACHE_MIN_STRLEN
         ? cachedHashString(o)
         : hashString(o);
+    case 'symbol': {
+      const desc = o.description;
+      return typeof desc === 'string' &&
+        desc.length > STRING_HASH_CACHE_MIN_STRLEN
+        ? cachedHashString(desc)
+        : hashString(desc);
+    }
     case 'object':
     case 'function':
       if (o === null) {