Bug: Angle Brackets as Math Operators Corrupt Depth Parsing

[squid-protocol]

Bug: Angle Brackets as Math Operators Corrupt Depth Parsing

Description

In gitgalaxy/core/detector.py, the _count_top_level_args method blindly treats angle brackets < and > as scope delimiters to support generics (e.g., List<String>). However, these characters double as math operators (less-than, greater-than, left-shift).

elif ch in "([{<":
    depth += 1
elif ch in ")]}>":
    if ch == ">" and i > 0 and body[i - 1] in "=-":
        pass
    elif depth > 0:
        depth -= 1

Impact

When < or > is used as a math or comparison operator inside a default argument value, it corrupts the depth counter for the remainder of the parameter block:

• Less-than operator (a = x < y): The < increments the depth counter permanently since there is no matching >. This causes all subsequent top-level commas to be ignored as if they were inside a generic bracket, resulting in severe undercounting.
• Greater-than operator (a = (x > y, z)): The > prematurely decrements the depth counter. If it decrements the depth to 0, nested commas (like the one separating x > y and z) are exposed and erroneously counted as top-level argument separators, resulting in overcounting.

Steps to Reproduce

1. Test with: def foo(a = (x < y), b = 2) -> Returns 1 argument (undercounted).
2. Test with: def foo(a = (x > y, z), b = 2) -> Returns 3 arguments (overcounted).

Suggested Fix

Consider detecting whether < or > is part of a balanced generic block or surrounded by spaces/math structures to distinguish them from standard operators, or restrict their generic-bracket behavior solely to statically-typed languages.

[squid-protocol]

Fixed in #1884 (merged). Angle-bracket depth tracking in _count_top_level_args is now gated to _ANGLE_BRACKET_GENERIC_LANGUAGES (cpp/rust/csharp/java/kotlin/scala/typescript/swift/go/dart), so </> used as comparison/shift operators in a default value no longer corrupt the depth counter. Verified: def foo(a = (x < y), b = 2) and def foo(a = (x > y, z), b = 2) both return 2 now. Regression test test_count_top_level_args_angle_brackets_as_math_operators_1853 passes on current main.

Note: the harder residual case — </> ambiguity inside a generic-using language's own default-value expressions — remains, as #1884 called out; that needs a type-aware parser. Opening a narrow follow-up only if it shows up in real corpus data.