regexx/tests/cases.py

"""Test cases for regexx, checked against CPython's own `re` module
(concept.md Section 11). Each case records a pattern/subject pair and
an operation; gen.py computes the expected result with Python's `re`
and emits a C assertion that checks regexx against it.
"""

CASES = []


def add(op, pattern, subject, mode="utf8", flags=(), **kw):
    CASES.append(dict(op=op, pattern=pattern, subject=subject, mode=mode, flags=tuple(flags), **kw))


# ---- literals, concatenation, anchors --------------------------------
add("search", r"abc", "xxabcxx")
add("fullmatch", r"abc", "abc")
add("fullmatch", r"abc", "xabc")
add("match", r"abc", "abcdef")
add("match", r"abc", "xabcdef")
add("search", r"^abc$", "abc")
add("search", r"^abc$", "xabc")
add("search", r"^abc", "abc\nabc", flags=["MULTILINE"])
add("finditer", r"^abc", "abc\nabc", flags=["MULTILINE"])
add("search", r"abc$", "xxabc\nabc", flags=["MULTILINE"])
add("search", r"\Aabc", "abc")
add("search", r"abc\Z", "xxabc")
add("search", r"abc\Z", "xxabc\n")

# ---- character classes -------------------------------------------------
add("search", r"[a-z]+", "ABCdefGHI")
add("search", r"[^a-z]+", "abcDEFghi")
add("search", r"[a-z]+", "ABC", flags=["IGNORECASE"])
add("finditer", r"[abc]", "xaybzc")
add("search", r"[]a]", "]a")  # ']' literal as first class member
add("search", r"[a\-z]", "-")

# ---- shorthand classes ---------------------------------------------------
add("finditer", r"\d+", "ab123cd45")
add("finditer", r"\D+", "ab123cd45")
add("search", r"\s+", "a   b")
add("search", r"\S+", "   ab  ")
add("finditer", r"\w+", "hi there, friend!")
add("finditer", r"\W+", "hi there, friend!")
add("search", r"[\d\S]", " ")
add("search", r"[\d\S]", "5")

# ---- word boundaries ------------------------------------------------------
add("finditer", r"\bcat\b", "cat catalog cat")
add("finditer", r"\Bcat\B", "concatenate")

# ---- quantifiers ------------------------------------------------------------
add("search", r"a*", "aaab")
add("search", r"a+", "baaab")
add("search", r"a?b", "b")
add("search", r"a{2,4}", "aaaaa")
add("search", r"a{2,4}?", "aaaaa")
add("search", r"a{3}", "aa")
add("search", r"a.*b", "axxxbxxxb")
add("search", r"a.*?b", "axxxbxxxb")
add("finditer", r"a*", "baaab")  # exercises empty-match advancement

# ---- alternation and groups -------------------------------------------------
add("search", r"(foo|bar)baz", "barbaz")
add("search", r"(?:foo|bar)baz", "foobaz")
add("finditer", r"(a)(b)?", "ab a")
add("search", r"(?P<year>\d{4})-(?P<month>\d{2})", "2024-09")

# ---- backreferences ---------------------------------------------------------
add("search", r"(\w+) \1", "hello hello")
add("search", r"(\w+) \1", "hello world")
add("search", r"(?P<w>\w+) (?P=w)", "abc abc")
add("search", r"(\w)\1", "aa")
add("search", r"(\w)\1", "ab")

# ---- lookaround --------------------------------------------------------------
add("search", r"foo(?=bar)", "foobar")
add("search", r"foo(?=bar)", "foobaz")
add("search", r"foo(?!bar)", "foobaz")
add("search", r"foo(?!bar)", "foobar")
add("search", r"(?<=foo)bar", "foobar")
add("search", r"(?<=foo)bar", "xxxbar")
add("search", r"(?<!foo)bar", "xxxbar")
add("search", r"(?<!foo)bar", "foobar")
add("finditer", r"(?<=\d)(?=(\d{3})+(?!\d))", "1234567")  # thousands-separator style

# ---- atomic groups / possessive quantifiers -----------------------------------
add("search", r"a(?>bc|b)c", "abc")
add("search", r"a(bc|b)c", "abc")
add("search", r"a*+a", "aaaa")
add("search", r"a*a", "aaaa")

# ---- DOTALL / VERBOSE ----------------------------------------------------------
add("search", r"a.b", "a\nb")
add("search", r"a.b", "a\nb", flags=["DOTALL"])
add("search", r"""
    \d+  # the integer part
    \.   # the dot
    \d+  # the fractional part
""", "pi is 3.14 roughly", flags=["VERBOSE"])

# ---- escapes ---------------------------------------------------------------------
add("search", r"a\tb", "a\tb")
add("search", r"\x41\x42", "AB")
add("search", r"é", "café")

# ---- UTF-8 mode ------------------------------------------------------------------
add("search", r"\w+", "café au lait")
add("finditer", r"\w+", "café 中文 word")
add("search", r"[à-ÿ]+", "éèê")

# ---- sub / subn -------------------------------------------------------------------
add("sub", r"a", "banana", repl="o", count=0)
add("sub", r"a", "banana", repl="o", count=2)
add("sub", r"(\w+)@(\w+)", "user@host", repl=r"\2@\1")
add("sub", r"(?P<user>\w+)@(?P<host>\w+)", "user@host", repl=r"\g<host>@\g<user>")
add("sub", r"\s+", "a   b    c", repl=" ")

# ---- split ------------------------------------------------------------------------
add("split", r"[,;]\s*", "a, b;c ,  d")
add("split", r"(,)", "a,b,c")
add("split", r"\s*", "abc")
add("split", r",", "a,b,c", maxsplit=1)

# ---- ASCII vs UTF8 mode differences for \w ----------------------------------------
add("search", r"\w+", "café", mode="ascii")

# ---- BINARY mode --------------------------------------------------------------------
add("search", r"a.c", "a\x00c", mode="binary")
add("finditer", r"\d+", "12ab34", mode="binary")