Capstone Session Step 1: First Attempt, Rejected

"""Capstone attempt 1: parse_duration -- convert an "1h30m"-style duration string to total seconds."""  # => co-05: restates the prompt's own framing
from __future__ import annotations  # => DD-39 hygiene
 
import re  # => co-05: stdlib-only per the prompt's constraint
 
_TOKEN = re.compile(r"(\d+)([hms])")  # => matches one <digits><unit> token, e.g. "30m"
_UNIT_SECONDS: dict[str, int] = {"h": 3600, "m": 600, "s": 1}  # => co-16: LOOKS right, IS wrong -- "m" should map to 60, not 600
 
 
def parse_duration(s: str) -> int:  # => co-05: matches the prompt's exact signature
    """Parse a duration string like "1h30m" or "45s" into total whole seconds."""
    if not s:  # => co-05: satisfies the empty-string acceptance bullet
        raise ValueError("duration string must not be empty")
    total = 0
    consumed = 0
    for match in _TOKEN.finditer(s):  # => co-07: walks every token the regex can find
        value = int(match.group(1))
        unit = match.group(2)
        total += value * _UNIT_SECONDS[unit]  # => co-16: silently wrong for every "m" token
        consumed += len(match.group(0))
    if consumed != len(s):  # => co-05: satisfies the garbage-suffix / no-valid-tokens bullets
        raise ValueError(f"invalid duration string: {s!r}")
    return total

F.F....                                                                  [100%]
=================================== FAILURES ===================================
____________________________ test_hours_and_minutes ____________________________
 
    def test_hours_and_minutes():
>       assert parse_duration("1h30m") == 5400
E       AssertionError: assert 21600 == 5400
E        +  where 21600 = parse_duration('1h30m')
 
test_parse_duration.py:6: AssertionError
_____________________________ test_all_three_units _____________________________
 
    def test_all_three_units():
>       assert parse_duration("1h1m1s") == 3661
E       AssertionError: assert 4201 == 3661
E        +  where 4201 = parse_duration('1h1m1s')
 
test_parse_duration.py:14: AssertionError
=========================== short test summary info ============================
FAILED test_parse_duration.py::test_hours_and_minutes - AssertionError: asser...
FAILED test_parse_duration.py::test_all_three_units - AssertionError: assert ...
2 failed, 5 passed in 0.01s