[CC-005] Missing date validation in cost_collect.py

[LFigg]

Description

Date parameters are not validated early, leading to cryptic API errors when invalid dates are provided.

Location

• File: cost_collect.py - CLI argument handling

Impact

• Poor user experience
• Time wasted on failed collection
• Cryptic error messages from cloud APIs

Note

This overlaps with TD-016 but is specific to cost_collect.py.

Suggested Fix

Add validation in argument parser:

def valid_date(s: str) -> datetime:
    try:
        return datetime.strptime(s, '%Y-%m-%d')
    except ValueError:
        raise argparse.ArgumentTypeError(f"Invalid date: {s}. Use YYYY-MM-DD")

parser.add_argument('--start-date', type=valid_date)
parser.add_argument('--end-date', type=valid_date)

Also validate that start_date < end_date and range is not too large.

Priority

Medium

Source

cost_collect.py code review - CC-005