🧪 Add tests and fix bugs for evaluate_gsm8k numeric parser

[dhanush342]

🎯 What: The testing gap in parse_numeric within evaluate_gsm8k.py is now addressed with a robust test suite. Additionally, two silent parsing bugs were identified and fixed (support for negative fractions like -1/2 and decimals without leading zeros like .5).
📊 Coverage: Scenarios covered include:

• Valid positive/negative integers, decimals, and fractions.
• Empty strings, None, invalid types, and division by zero.
• Extracting numbers from mixed text strings.
• Falling back appropriately to the last numeric token.
  ✨ Result: Test coverage for parse_numeric is now significantly improved, and the function correctly handles a wider range of numeric formats without throwing exceptions. The testing leverages unittest.mock for sys.modules to decouple the testing script from heavy ML dependencies.

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PR created automatically by Jules for task 1898371315961863988 started by @dhanush342

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[Copilot]

Pull request overview

Adds regression tests around evaluate_gsm8k.parse_numeric and adjusts its regexes to correctly parse additional GSM8K-style numeric formats (negative fractions and leading-dot decimals).

Changes:

• Extend fraction parsing to accept negative numerators (e.g., -1/2).
• Extend decimal parsing to accept leading-dot decimals (e.g., .5, -.5).
• Add a new test suite covering valid/invalid numeric strings and extraction from mixed text.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
evaluate_gsm8k.py	Updates regex-based numeric extraction to handle additional numeric formats.
test_evaluate_gsm8k.py	Adds tests for parse_numeric, with module mocking to avoid importing heavy deps.

Comments suppressed due to low confidence (1)

evaluate_gsm8k.py:25

• parse_numeric prefers the last numeric token, but the fraction branch uses re.search(...) which returns the first fraction in the string. This can yield inconsistent results for outputs containing multiple fractions (e.g., explanations before the final answer). Consider collecting all fraction matches (e.g., via re.findall/re.finditer) and using the last match to align with the “prefer last token” heuristic.

    frac_match = re.search(r"(-?\d+)/(\d+)", s)
    if frac_match:
        try:
            return float(Fraction(int(frac_match.group(1)), int(frac_match.group(2))))
        except Exception:

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