From e0b413383cb876153f76dd262c53cbbba1bfac09 Mon Sep 17 00:00:00 2001
From: h7x4 <h7x4@nani.wtf>
Date: Thu, 4 Jun 2026 16:09:11 +0900
Subject: [PATCH] kana_transliteration: fix k->h , add more tests

---
 src/kana_transliteration.rs | 77 ++++++++++++++++++++++++++++++++-----
 1 file changed, 67 insertions(+), 10 deletions(-)

diff --git a/src/kana_transliteration.rs b/src/kana_transliteration.rs
index a01f317..645a80f 100644
--- a/src/kana_transliteration.rs
+++ b/src/kana_transliteration.rs
@@ -115,7 +115,7 @@ fn katakana_vowel_map(katakana: char) -> Option<char> {
 // - Halfwidth and Fullwidth Forms: https://www.unicode.org/charts/PDF/UFF00.pdf
 
 pub fn transliterate_katakana_to_hiragana(katakana: &str) -> String {
-    let first_pass = transpose_codepoints_in_range(katakana, -96, 'ア'.into(), 'ヶ'.into());
+    let first_pass = transpose_codepoints_in_range(katakana, -96, 'ァ'.into(), 'ヶ'.into());
 
     // TODO: don't create a new result, just mutate the first pass in-place.
     let chars = first_pass.chars().collect::<Vec<_>>();
@@ -458,11 +458,44 @@ pub fn transliterate_fullwidth_katakana_to_halfwidth_katakana(fullwidth: &str) -
 mod tests {
     use super::*;
 
+    // KATAKANA TO HIRAGANA
+
     #[test]
     fn test_katakana_to_hiragana() {
         assert_eq!(transliterate_katakana_to_hiragana("カタカナ"), "かたかな");
     }
 
+    #[test]
+    fn test_katakana_to_hiragana_with_dakuten() {
+        assert_eq!(
+            transliterate_katakana_to_hiragana("ガダガナピ"),
+            "がだがなぴ"
+        );
+    }
+
+    #[test]
+    fn test_katakana_to_hiragana_with_small_tsu() {
+        assert_eq!(transliterate_katakana_to_hiragana("ハッパ"), "はっぱ");
+    }
+
+    #[test]
+    fn test_katakana_to_hiragana_with_small_aiueo() {
+        assert_eq!(
+            transliterate_katakana_to_hiragana("ハァヒィフゥヘェホォ"),
+            "はぁひぃふぅへぇほぉ"
+        );
+    }
+
+    #[test]
+    fn test_katakana_to_hiragana_with_small_ka_ke() {
+        assert_eq!(transliterate_katakana_to_hiragana("カヵヶ"), "かゕゖ");
+    }
+
+    #[test]
+    fn test_katakana_to_hiragana_wi_we() {
+        assert_eq!(transliterate_katakana_to_hiragana("ヰヱ"), "ゐゑ");
+    }
+
     #[test]
     fn test_katakana_to_hiragana_long_vocal_to_dash() {
         assert_eq!(
@@ -503,14 +536,41 @@ mod tests {
         assert_eq!(transliterate_katakana_to_hiragana("サヾーエ"), "さゞあえ");
     }
 
-    #[test]
-    fn test_katakana_to_hiragana_wi_we() {
-        assert_eq!(transliterate_katakana_to_hiragana("ヰヱ"), "ゐゑ");
-    }
+    // HIRAGANA TO KATAKANA
 
     #[test]
     fn test_hiragana_to_katakana() {
-        assert_eq!(transliterate_hiragana_to_katakana("ひらがな"), "ヒラガナ");
+        assert_eq!(transliterate_hiragana_to_katakana("ひらかな"), "ヒラカナ");
+    }
+    #[test]
+    fn test_hiragana_to_katakana_with_dakuten() {
+        assert_eq!(
+            transliterate_hiragana_to_katakana("がだがなぴ"),
+            "ガダガナピ"
+        );
+    }
+
+    #[test]
+    fn test_hiragana_to_katakana_with_small_tsu() {
+        assert_eq!(transliterate_hiragana_to_katakana("はっぱ"), "ハッパ");
+    }
+
+    #[test]
+    fn test_hiragana_to_katakana_with_small_aiueo() {
+        assert_eq!(
+            transliterate_hiragana_to_katakana("はぁひぃふぅへぇほぉ"),
+            "ハァヒィフゥヘェホォ"
+        );
+    }
+
+    #[test]
+    fn test_hiragana_to_katakana_with_small_ka_ke() {
+        assert_eq!(transliterate_hiragana_to_katakana("かゕゖ"), "カヵヶ");
+    }
+
+    #[test]
+    fn test_hiragana_to_katakana_wi_we() {
+        assert_eq!(transliterate_hiragana_to_katakana("ゐゑ"), "ヰヱ");
     }
 
     #[test]
@@ -529,10 +589,7 @@ mod tests {
         );
     }
 
-    #[test]
-    fn test_hiragana_to_katakana_wi_we() {
-        assert_eq!(transliterate_hiragana_to_katakana("ゐゑ"), "ヰヱ");
-    }
+    /// FULLWIDTH/HALFWIDTH
 
     #[test]
     fn test_fullwidth_romaji_to_halfwidth_romaji() {