Add normalization of combining dakuten and handakuten to ja preprocessors (#1136)

* Add normalization of combining dakuten and handakuten to ja preprocessors

* Fix typo

* Remove redundant variable assignment

* Fix first character processed incorrectly when it is a character that gets combined

* Add test for combining dakuten and handakuten

1 files changed, 202 insertions, 0 deletions

diff --git a/test/language/japanese-preprocessors.test.js b/test/language/japanese-preprocessors.test.js
new file mode 100644
index 00000000..90313abd
--- /dev/null
+++ b/test/language/japanese-preprocessors.test.js
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2024  Yomitan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import {describe, expect, test} from 'vitest';
+import {normalizeCombiningCharacters} from '../../ext/js/language/ja/japanese-text-preprocessors.js';
+
+const testCasesDakuten = [
+    ['か\u3099', 'が'],
+    ['き\u3099', 'ぎ'],
+    ['く\u3099', 'ぐ'],
+    ['け\u3099', 'げ'],
+    ['こ\u3099', 'ご'],
+    ['さ\u3099', 'ざ'],
+    ['し\u3099', 'じ'],
+    ['す\u3099', 'ず'],
+    ['せ\u3099', 'ぜ'],
+    ['そ\u3099', 'ぞ'],
+    ['た\u3099', 'だ'],
+    ['ち\u3099', 'ぢ'],
+    ['つ\u3099', 'づ'],
+    ['て\u3099', 'で'],
+    ['と\u3099', 'ど'],
+    ['は\u3099', 'ば'],
+    ['ひ\u3099', 'び'],
+    ['ふ\u3099', 'ぶ'],
+    ['へ\u3099', 'べ'],
+    ['ほ\u3099', 'ぼ'],
+    ['カ\u3099', 'ガ'],
+    ['キ\u3099', 'ギ'],
+    ['ク\u3099', 'グ'],
+    ['ケ\u3099', 'ゲ'],
+    ['コ\u3099', 'ゴ'],
+    ['サ\u3099', 'ザ'],
+    ['シ\u3099', 'ジ'],
+    ['ス\u3099', 'ズ'],
+    ['セ\u3099', 'ゼ'],
+    ['ソ\u3099', 'ゾ'],
+    ['タ\u3099', 'ダ'],
+    ['チ\u3099', 'ヂ'],
+    ['ツ\u3099', 'ヅ'],
+    ['テ\u3099', 'デ'],
+    ['ト\u3099', 'ド'],
+    ['ハ\u3099', 'バ'],
+    ['ヒ\u3099', 'ビ'],
+    ['フ\u3099', 'ブ'],
+    ['ヘ\u3099', 'ベ'],
+    ['ホ\u3099', 'ボ'],
+];
+
+const testCasesHandakuten = [
+    ['は\u309A', 'ぱ'],
+    ['ひ\u309A', 'ぴ'],
+    ['ふ\u309A', 'ぷ'],
+    ['へ\u309A', 'ぺ'],
+    ['ほ\u309A', 'ぽ'],
+    ['ハ\u309A', 'パ'],
+    ['ヒ\u309A', 'ピ'],
+    ['フ\u309A', 'プ'],
+    ['ヘ\u309A', 'ペ'],
+    ['ホ\u309A', 'ポ'],
+];
+
+const testCasesIgnored = [
+    ['な\u3099', 'な\u3099'],
+    ['な\u309A', 'な\u309A'],
+    ['に\u3099', 'に\u3099'],
+    ['に\u309A', 'に\u309A'],
+    ['ぬ\u3099', 'ぬ\u3099'],
+    ['ぬ\u309A', 'ぬ\u309A'],
+    ['ね\u3099', 'ね\u3099'],
+    ['ね\u309A', 'ね\u309A'],
+    ['の\u3099', 'の\u3099'],
+    ['の\u309A', 'の\u309A'],
+    ['ま\u3099', 'ま\u3099'],
+    ['ま\u309A', 'ま\u309A'],
+    ['み\u3099', 'み\u3099'],
+    ['み\u309A', 'み\u309A'],
+    ['む\u3099', 'む\u3099'],
+    ['む\u309A', 'む\u309A'],
+    ['め\u3099', 'め\u3099'],
+    ['め\u309A', 'め\u309A'],
+    ['も\u3099', 'も\u3099'],
+    ['も\u309A', 'も\u309A'],
+    ['ゃ\u3099', 'ゃ\u3099'],
+    ['ゃ\u309A', 'ゃ\u309A'],
+    ['や\u3099', 'や\u3099'],
+    ['や\u309A', 'や\u309A'],
+    ['ゅ\u3099', 'ゅ\u3099'],
+    ['ゅ\u309A', 'ゅ\u309A'],
+    ['ゆ\u3099', 'ゆ\u3099'],
+    ['ゆ\u309A', 'ゆ\u309A'],
+    ['ょ\u3099', 'ょ\u3099'],
+    ['ょ\u309A', 'ょ\u309A'],
+    ['よ\u3099', 'よ\u3099'],
+    ['よ\u309A', 'よ\u309A'],
+    ['ら\u3099', 'ら\u3099'],
+    ['ら\u309A', 'ら\u309A'],
+    ['り\u3099', 'り\u3099'],
+    ['り\u309A', 'り\u309A'],
+    ['る\u3099', 'る\u3099'],
+    ['る\u309A', 'る\u309A'],
+    ['れ\u3099', 'れ\u3099'],
+    ['れ\u309A', 'れ\u309A'],
+    ['ろ\u3099', 'ろ\u3099'],
+    ['ろ\u309A', 'ろ\u309A'],
+    ['ゎ\u3099', 'ゎ\u3099'],
+    ['ゎ\u309A', 'ゎ\u309A'],
+    ['わ\u3099', 'わ\u3099'],
+    ['わ\u309A', 'わ\u309A'],
+    ['ゐ\u3099', 'ゐ\u3099'],
+    ['ゐ\u309A', 'ゐ\u309A'],
+    ['ゑ\u3099', 'ゑ\u3099'],
+    ['ゑ\u309A', 'ゑ\u309A'],
+    ['を\u3099', 'を\u3099'],
+    ['を\u309A', 'を\u309A'],
+    ['ん\u3099', 'ん\u3099'],
+    ['ん\u309A', 'ん\u309A'],
+    ['ナ\u3099', 'ナ\u3099'],
+    ['ナ\u309A', 'ナ\u309A'],
+    ['ニ\u3099', 'ニ\u3099'],
+    ['ニ\u309A', 'ニ\u309A'],
+    ['ヌ\u3099', 'ヌ\u3099'],
+    ['ヌ\u309A', 'ヌ\u309A'],
+    ['ネ\u3099', 'ネ\u3099'],
+    ['ネ\u309A', 'ネ\u309A'],
+    ['ノ\u3099', 'ノ\u3099'],
+    ['ノ\u309A', 'ノ\u309A'],
+    ['マ\u3099', 'マ\u3099'],
+    ['マ\u309A', 'マ\u309A'],
+    ['ミ\u3099', 'ミ\u3099'],
+    ['ミ\u309A', 'ミ\u309A'],
+    ['ム\u3099', 'ム\u3099'],
+    ['ム\u309A', 'ム\u309A'],
+    ['メ\u3099', 'メ\u3099'],
+    ['メ\u309A', 'メ\u309A'],
+    ['モ\u3099', 'モ\u3099'],
+    ['モ\u309A', 'モ\u309A'],
+    ['ャ\u3099', 'ャ\u3099'],
+    ['ャ\u309A', 'ャ\u309A'],
+    ['ヤ\u3099', 'ヤ\u3099'],
+    ['ヤ\u309A', 'ヤ\u309A'],
+    ['ュ\u3099', 'ュ\u3099'],
+    ['ュ\u309A', 'ュ\u309A'],
+    ['ユ\u3099', 'ユ\u3099'],
+    ['ユ\u309A', 'ユ\u309A'],
+    ['ョ\u3099', 'ョ\u3099'],
+    ['ョ\u309A', 'ョ\u309A'],
+    ['ヨ\u3099', 'ヨ\u3099'],
+    ['ヨ\u309A', 'ヨ\u309A'],
+    ['ラ\u3099', 'ラ\u3099'],
+    ['ラ\u309A', 'ラ\u309A'],
+    ['リ\u3099', 'リ\u3099'],
+    ['リ\u309A', 'リ\u309A'],
+    ['ル\u3099', 'ル\u3099'],
+    ['ル\u309A', 'ル\u309A'],
+    ['レ\u3099', 'レ\u3099'],
+    ['レ\u309A', 'レ\u309A'],
+    ['ロ\u3099', 'ロ\u3099'],
+    ['ロ\u309A', 'ロ\u309A'],
+    ['ヮ\u3099', 'ヮ\u3099'],
+    ['ヮ\u309A', 'ヮ\u309A'],
+    ['ワ\u3099', 'ワ\u3099'],
+    ['ワ\u309A', 'ワ\u309A'],
+    ['ヰ\u3099', 'ヰ\u3099'],
+    ['ヰ\u309A', 'ヰ\u309A'],
+    ['ヱ\u3099', 'ヱ\u3099'],
+    ['ヱ\u309A', 'ヱ\u309A'],
+    ['ヲ\u3099', 'ヲ\u3099'],
+    ['ヲ\u309A', 'ヲ\u309A'],
+    ['ン\u3099', 'ン\u3099'],
+    ['ン\u309A', 'ン\u309A'],
+];
+
+const textCasesMisc = [
+    ['', ''],
+    ['\u3099ハ', '\u3099ハ'],
+    ['\u309Aハ', '\u309Aハ'],
+    ['さくらし\u3099また\u3099いこん', 'さくらじまだいこん'],
+    ['いっほ\u309Aん', 'いっぽん'],
+];
+
+describe('combining dakuten/handakuten normalization', () => {
+    const {process} = normalizeCombiningCharacters;
+    const testCases = [...testCasesDakuten, ...testCasesHandakuten, ...testCasesIgnored, ...textCasesMisc];
+    test.each(testCases)('%s normalizes to %s', (input, expected) => {
+        expect(process(input, true)).toStrictEqual(expected);
+    });
+});