close #2; fix: regular express for 即係 with test cases

regular.txt

@@ -46,7 +46,7 @@ o 丫,吖
 [無冇] [咁甘噤],冇咁
 [無冇] [左咗唨],冇咗
 [撲扑] 街,仆街
-[姐遮] 係,即係
+(^|[^小家表姑契阿堂姐雨把擔收]) [姐遮] 係,\1即係
 [痴癡黐] [綫線],黐線
 [痴癡黐] [撚𠹌能] [綫線],黐撚線
 ([出過落入用再]) 黎,\1嚟

test.py

@@ -0,0 +1,49 @@
+from rules import apply_contextual_rules
+import re
+
+regular_typos = []
+
+# Read regular typos
+for line in open("./regular.txt", "r", encoding="utf-8"):
+    typo, replace = line.strip().split(",")
+    regular_typos.append(
+        (re.compile(typo.replace(" ", "\s*"), re.I), replace))
+
+def fix_regular_typo(line: str) -> str:
+    """
+    Regular typo means that they can be simply replaced by a regular expression.
+    Fixing them does not require any context information.
+    """
+    for typo, replace in regular_typos:
+        line = typo.sub(replace, line)
+    return line
+
+def correct(line):
+    stripped_line = line.strip()
+    fixed = fix_regular_typo(stripped_line)
+    fixed = apply_contextual_rules(fixed)
+
+    return fixed
+
+def test_即係():
+    # 遮
+    assert correct("遮係噉") == "即係噉"
+    assert correct("哪！遮係噉") == "哪！即係噉"
+    assert correct("落雨要擔遮係嗎？") == "落雨要擔遮係嗎？"
+    assert correct("落雨要把遮係嗎？") == "落雨要把遮係嗎？"
+    assert correct("落雨要收遮係嗎？") == "落雨要收遮係嗎？"
+    assert correct("落雨要雨遮係嗎？") == "落雨要雨遮係嗎？"
+
+    # 姐
+    assert correct("姐係噉") == "即係噉"
+    assert correct("哪！姐係噉") == "哪！即係噉"
+    assert correct("我家姐係我親人") == "我家姐係我親人"
+    assert correct("我表姐係我親人") == "我表姐係我親人"
+    assert correct("我堂姐係我親人") == "我堂姐係我親人"
+    assert correct("我契姐係我親人") == "我契姐係我親人"
+    assert correct("我姐姐係我親人") == "我姐姐係我親人"
+    assert correct("我姑姐係我親人") == "我姑姐係我親人"
+    assert correct("我小姐係我親人") == "我小姐係我親人"
+
+if __name__ == "__main__":
+    test_即係()