Remove hashnode as a dependency and localize its functionality to the package.

Maintenance was done long time ago hence no need to wait for the update

lib/models/documents/attribute.dart

@@ -1,4 +1,5 @@
-import 'package:quiver_hashcode/hashcode.dart';
+
+import 'package:flutter_quill/utils/hashcode.dart' as hashcode;
 
 enum AttributeScope {
   INLINE, // refer to https://quilljs.com/docs/formats/#inline
@@ -181,7 +182,7 @@ class Attribute<T> {
   }
 
   @override
-  int get hashCode => hash3(key, scope, value);
+  int get hashCode => hashcode.hash3(key, scope, value);
 
   @override
   String toString() {

lib/models/documents/style.dart

@@ -1,6 +1,6 @@
 import 'package:collection/collection.dart';
 import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:quiver_hashcode/hashcode.dart';
+import 'package:flutter_quill/utils/hashcode.dart' as hashcode;
 
 /* Collection of style attributes */
 class Style {
@@ -101,8 +101,8 @@ class Style {
   @override
   int get hashCode {
     final hashes =
-        _attributes.entries.map((entry) => hash2(entry.key, entry.value));
+        _attributes.entries.map((entry) => hashcode.hash2(entry.key, entry.value));
-    return hashObjects(hashes);
+    return hashcode.hashObjects(hashes);
   }
 
   @override

lib/models/quill_delta.dart

@@ -7,7 +7,7 @@ library quill_delta;
 import 'dart:math' as math;
 
 import 'package:collection/collection.dart';
-import 'package:quiver_hashcode/hashcode.dart';
+import 'package:flutter_quill/utils/hashcode.dart' as hashcode;
 
 const _attributeEquality = DeepCollectionEquality();
 const _valueEquality = DeepCollectionEquality();
@@ -155,10 +155,10 @@ class Operation {
   int get hashCode {
     if (_attributes != null && _attributes!.isNotEmpty) {
       final attrsHash =
-          hashObjects(_attributes!.entries.map((e) => hash2(e.key, e.value)));
+          hashcode.hashObjects(_attributes!.entries.map((e) => hashcode.hash2(e.key, e.value)));
-      return hash3(key, value, attrsHash);
+      return hashcode.hash3(key, value, attrsHash);
     }
-    return hash2(key, value);
+    return hashcode.hash2(key, value);
   }
 
   @override
@@ -301,7 +301,7 @@ class Delta {
   }
 
   @override
-  int get hashCode => hashObjects(_operations);
+  int get hashCode => hashcode.hashObjects(_operations);
 
   /// Retain [count] of characters from current position.
   void retain(int count, [Map<String, dynamic>? attributes]) {

lib/utils/hashcode.dart

@@ -0,0 +1,31 @@
+library quiver.hashcode;
+
+/// Generates a hash code for multiple [objects].
+int hashObjects(Iterable objects) =>
+    _finish(objects.fold(0, (h, i) => _combine(h, i.hashCode)));
+
+/// Generates a hash code for two objects.
+int hash2(a, b) => _finish(_combine(_combine(0, a.hashCode), b.hashCode));
+
+/// Generates a hash code for three objects.
+int hash3(a, b, c) => _finish(
+    _combine(_combine(_combine(0, a.hashCode), b.hashCode), c.hashCode));
+
+/// Generates a hash code for four objects.
+int hash4(a, b, c, d) => _finish(_combine(
+    _combine(_combine(_combine(0, a.hashCode), b.hashCode), c.hashCode),
+    d.hashCode));
+
+// Jenkins hash functions
+
+int _combine(int hash, int value) {
+  hash = 0x1fffffff & (hash + value);
+  hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
+  return hash ^ (hash >> 6);
+}
+
+int _finish(int hash) {
+  hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
+  hash = hash ^ (hash >> 11);
+  return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
+}

pubspec.lock

@@ -212,13 +212,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "3.0.0"
-  quiver_hashcode:
-    dependency: "direct main"
-    description:
-      name: quiver_hashcode
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.0"
   sky_engine:
     dependency: transitive
     description: flutter

pubspec.yaml

@@ -12,7 +12,6 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  quiver_hashcode: ^2.0.0
   collection: ^1.15.0
   tuple: ^2.0.0
   url_launcher: ^6.0.2