From ec5b6d044d010c323e844fde6ff1704f7d87c7b7 Mon Sep 17 00:00:00 2001
From: cm-ayf <cm.ayf2734@gmail.com>
Date: Wed, 17 Jan 2024 13:29:46 +0900
Subject: [PATCH] debug and test split_pattern

---
 crates/jlabel-question/src/lib.rs   | 11 +++++------
 crates/jlabel-question/src/tests.rs | 12 ++++++++----
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/crates/jlabel-question/src/lib.rs b/crates/jlabel-question/src/lib.rs
index 4307f81..46ba956 100644
--- a/crates/jlabel-question/src/lib.rs
+++ b/crates/jlabel-question/src/lib.rs
@@ -30,10 +30,6 @@ pub enum ParseError {
 }
 
 fn split_pattern(pattern: &str) -> Option<(&str, &str, &str)> {
-    if !pattern.len() < 4 {
-        return None;
-    }
-
     let start = if pattern.starts_with("*/") {
         4
     } else if pattern.starts_with('*') {
@@ -42,12 +38,15 @@ fn split_pattern(pattern: &str) -> Option<(&str, &str, &str)> {
         0
     };
     let end = if pattern.ends_with(":*") {
-        pattern.len() - 4
+        pattern.len().checked_sub(4)?
     } else if pattern.ends_with('*') {
-        pattern.len() - 2
+        pattern.len().checked_sub(2)?
     } else {
         pattern.len()
     };
+    if start > end {
+        return None;
+    }
 
     Some((&pattern[..start], &pattern[start..end], &pattern[end..]))
 }
diff --git a/crates/jlabel-question/src/tests.rs b/crates/jlabel-question/src/tests.rs
index 6289984..0540e19 100644
--- a/crates/jlabel-question/src/tests.rs
+++ b/crates/jlabel-question/src/tests.rs
@@ -3,10 +3,14 @@ use jlabel::{Label, Mora, Phoneme, Utterance, Word};
 
 #[test]
 fn splitter() {
-    assert_eq!(split_pattern("a^*"), Some(("", "a", "^*")));
-    assert_eq!(split_pattern("*/A:-??+*"), Some(("*/A:", "-??", "+*")));
-    assert_eq!(split_pattern("*|?+*"), Some(("*|", "?", "+*")));
-    assert_eq!(split_pattern("*-1"), Some(("*-", "1", "")));
+    assert_eq!(split_pattern("a^*").unwrap(), ("", "a", "^*"));
+    assert_eq!(split_pattern("*/A:-??+*").unwrap(), ("*/A:", "-??", "+*"));
+    assert_eq!(split_pattern("*|?+*").unwrap(), ("*|", "?", "+*"));
+    assert_eq!(split_pattern("*-1").unwrap(), ("*-", "1", ""));
+
+    assert!(split_pattern("*").is_none());
+    assert!(split_pattern(":*").is_none());
+    assert!(split_pattern("*/A:*").is_none());
 }
 
 #[test]