snapshot of https://github.com/mattermost/mattermost.git (master, 2026-09-16; blobs > 131072B omitted)

server/channels/utils/unicode_test.go

@@ -0,0 +1,124 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package utils
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNormalizeFilename(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "ASCII only",
+			input:    "test.jpg",
+			expected: "test.jpg",
+		},
+		{
+			name:     "Japanese katakana dakuten NFC",
+			input:    "\u30AC", // ガ (NFC)
+			expected: "\u30AC",
+		},
+		{
+			name:     "Japanese katakana dakuten NFD",
+			input:    "\u30AB\u3099", // カ + combining dakuten → ガ
+			expected: "\u30AC",
+		},
+		{
+			name:     "Japanese katakana handakuten NFC",
+			input:    "\u30D1", // パ (NFC)
+			expected: "\u30D1",
+		},
+		{
+			name:     "Japanese katakana handakuten NFD",
+			input:    "\u30CF\u309A", // ハ + combining handakuten → パ
+			expected: "\u30D1",
+		},
+		{
+			name:     "Japanese hiragana dakuten NFC",
+			input:    "\u3079", // べ (NFC)
+			expected: "\u3079",
+		},
+		{
+			name:     "Japanese hiragana dakuten NFD",
+			input:    "\u3078\u3099", // へ + combining dakuten → べ
+			expected: "\u3079",
+		},
+		{
+			name:     "Mixed path with NFD",
+			input:    "data/\u30AB\u3099test.jpg", // data/カ゛test.jpg
+			expected: "data/\u30ACtest.jpg",       // data/ガtest.jpg
+		},
+		{
+			name:     "Complex Japanese filename NFD",
+			input:    "\u304B\u3099\u304D\u3099\u3050", // が + ぎ + ぐ (NFD: か゛き゛く゛)
+			expected: "\u304C\u304E\u3050",             // がぎぐ (NFC)
+		},
+		{
+			name:     "Path with multiple NFD characters",
+			input:    "data/\u30D5\u309A\u30ED\u30B7\u3099\u30A7\u30AF\u30C8.png", // data/プロジェクト.png (NFD)
+			expected: "data/\u30D7\u30ED\u30B8\u30A7\u30AF\u30C8.png",             // data/プロジェクト.png (NFC)
+		},
+		{
+			name:     "Empty string",
+			input:    "",
+			expected: "",
+		},
+		{
+			name:     "Already NFC normalized",
+			input:    "ファイル名.txt",
+			expected: "ファイル名.txt",
+		},
+		{
+			name:     "Korean Hangul NFC",
+			input:    "\uAC00", // 가 (NFC precomposed)
+			expected: "\uAC00",
+		},
+		{
+			name:     "Korean Hangul NFD",
+			input:    "\u1100\u1161", // ᄀ + ᅡ (NFD Jamo) → 가
+			expected: "\uAC00",
+		},
+		{
+			name:     "Korean word NFD",
+			input:    "\u1112\u1161\u11AB\u1100\u1173\u11AF", // 한글 (NFD Jamo: 한글)
+			expected: "\uD55C\uAE00",                         // 한글 (NFC)
+		},
+		{
+			name:     "Korean filename with path NFD",
+			input:    "data/\u1111\u1161\u110B\u1175\u11AF.txt", // 파일 (NFD) + .txt
+			expected: "data/\uD30C\uC77C.txt",                   // 파일.txt (NFC)
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := NormalizeFilename(tt.input)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestNormalizeFilenameIdempotent(t *testing.T) {
+	// NFC normalization should be idempotent
+	inputs := []string{
+		"test.jpg",
+		"\u30AC",       // ガ (NFC)
+		"\u30AB\u3099", // カ + combining dakuten (NFD)
+		"data/テスト.jpg",
+		"\uD55C\uAE00",                         // 한글 (NFC)
+		"\u1112\u1161\u11AB\u1100\u1173\u11AF", // 한글 (NFD Jamo)
+		"",
+	}
+
+	for _, input := range inputs {
+		first := NormalizeFilename(input)
+		second := NormalizeFilename(first)
+		assert.Equal(t, first, second, "NormalizeFilename should be idempotent for input: %q", input)
+	}
+}