From 0e856d2add54479d2a82a3bc958dd3058862d2b9 Mon Sep 17 00:00:00 2001
From: noncenz <33376717+noncenz@users.noreply.github.com>
Date: Thu, 5 Jan 2023 11:34:06 -0500
Subject: [PATCH] [PS-1352] Fix ignore diacritics in search (#2044)

* Fix ignore diacritics in search

This change updates the search function to ignore diacritical marks in search results. Marks are stripped from both the search input and results.

* Removed logs, added null or whitespace validation and improved formatting

Co-authored-by: aj-rosado <109146700+aj-rosado@users.noreply.github.com>
Co-authored-by: Andre Rosado <arosado@bitwarden.com>
---
 src/Core/Services/SearchService.cs     |  7 +++---
 src/Core/Utilities/StringExtensions.cs | 34 ++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 3 deletions(-)
 create mode 100644 src/Core/Utilities/StringExtensions.cs

diff --git a/src/Core/Services/SearchService.cs b/src/Core/Services/SearchService.cs
index 8a5b6ac7d..0c0bbfe17 100644
--- a/src/Core/Services/SearchService.cs
+++ b/src/Core/Services/SearchService.cs
@@ -5,6 +5,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Bit.Core.Abstractions;
 using Bit.Core.Models.View;
+using Bit.Core.Utilities;
 
 namespace Bit.Core.Services
 {
@@ -76,12 +77,12 @@ namespace Bit.Core.Services
             ct.ThrowIfCancellationRequested();
             var matchedCiphers = new List<CipherView>();
             var lowPriorityMatchedCiphers = new List<CipherView>();
-            query = query.Trim().ToLower();
+            query = query.Trim().ToLower().RemoveDiacritics();
 
             foreach (var c in ciphers)
             {
                 ct.ThrowIfCancellationRequested();
-                if (c.Name?.ToLower().Contains(query) ?? false)
+                if (c.Name?.ToLower().RemoveDiacritics().Contains(query) ?? false)
                 {
                     matchedCiphers.Add(c);
                 }
@@ -89,7 +90,7 @@ namespace Bit.Core.Services
                 {
                     lowPriorityMatchedCiphers.Add(c);
                 }
-                else if (c.SubTitle?.ToLower().Contains(query) ?? false)
+                else if (c.SubTitle?.ToLower().RemoveDiacritics().Contains(query) ?? false)
                 {
                     lowPriorityMatchedCiphers.Add(c);
                 }
diff --git a/src/Core/Utilities/StringExtensions.cs b/src/Core/Utilities/StringExtensions.cs
new file mode 100644
index 000000000..a37dc9f49
--- /dev/null
+++ b/src/Core/Utilities/StringExtensions.cs
@@ -0,0 +1,34 @@
+using System;
+using System.Globalization;
+using System.Text;
+
+namespace Bit.Core.Utilities
+{
+    public static class StringExtensions
+    {
+        public static string RemoveDiacritics(this string text)
+        {
+            if (string.IsNullOrWhiteSpace(text))
+            {
+                return text;
+            }
+
+            var normalizedString = text.Normalize(NormalizationForm.FormD);
+            var stringBuilder = new StringBuilder(capacity: normalizedString.Length);
+
+            for (int i = 0; i < normalizedString.Length; i++)
+            {
+                char c = normalizedString[i];
+                var unicodeCategory = CharUnicodeInfo.GetUnicodeCategory(c);
+                if (unicodeCategory != UnicodeCategory.NonSpacingMark)
+                {
+                    stringBuilder.Append(c);
+                }
+            }
+
+            return stringBuilder
+                .ToString()
+                .Normalize(NormalizationForm.FormC);
+        }
+    }
+}