claude-code-hooks

# Hook: Data Validation

## Description
This hook validates input data against a set of predefined rules.

## Use Case
Use this hook to ensure data integrity before processing or storing it in a database.

## Code
```python
import re

def validate_data(data, rules):
    errors = []
    for field, rule in rules.items():
        if field not in data:
            errors.append(f"Missing field: {field}")
            continue
        if not re.match(rule['pattern'], data[field]):
            errors.append(f"Invalid {field}: {data[field]}")
    return errors if errors else True

rules = {
    'email': {
        'pattern': r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$
    },
    'phone': {
        'pattern': r'^\+?[0-9]{10,15}$'
    }
}

data = {
    'email': 'user@example.com',
    'phone': '+1234567890'
}

validation_result = validate_data(data, rules)

if validation_result is True:
    print("Data is valid")
else:
    print("Data validation errors:", validation_result)
```

## Explanation
This hook defines a `validate_data` function that takes input data and a set of rules as arguments. The rules specify the expected pattern for each field. The function checks each field in the data against its corresponding rule and returns a list of errors if any field fails validation. If all fields pass validation, the function returns `True`. The example demonstrates how to use the hook to validate an email and phone number.