refactor: Replace unwrap() calls with proper error handling in model/option.rs

[joaquinbejar]

Issue #3: Reduce .unwrap() usage in model/option.rs

Title

refactor: Replace unwrap() calls with proper error handling in model/option.rs

Labels

• refactor
• error-handling
• priority-high

Description

The file src/model/option.rs contains 134 occurrences of .unwrap(). The Options struct is fundamental to the library and should handle errors gracefully.

Current State

• 134 .unwrap() calls in production code
• Core option operations can panic
• Invalid option parameters cause crashes instead of errors

Target State

• Zero .unwrap() calls in production code
• All public methods return Result where failure is possible
• Clear error messages for invalid parameters

Tasks

• Audit all .unwrap() calls in model/option.rs
• Replace with proper error handling using OptionsError
• Ensure all public methods return Result where failure is possible
• Add validation for option parameters:
  • Strike price > 0
  • Underlying price > 0
  • Volatility > 0
  • Time to expiration >= 0
• Update documentation with error conditions
• Run make lint-fix and make pre-push to verify

Acceptance Criteria

• No .unwrap() calls remain in production code
• All existing tests pass
• API documentation includes error conditions
• Invalid parameters produce clear error messages
• Option creation validates all inputs

Technical Notes

Validation Pattern

impl Options {
    pub fn new(
        strike: Positive,
        underlying: Positive,
        volatility: Positive,
        // ...
    ) -> Result<Self, OptionsError> {
        // Validation is handled by Positive type
        // Additional business logic validation here
        
        Ok(Self {
            strike,
            underlying,
            volatility,
            // ...
        })
    }
}

Error Handling Pattern

// Before
let price = self.calculate_price().unwrap();

// After
let price = self.calculate_price()
    .map_err(|e| OptionsError::PricingFailed(e.to_string()))?;

Files to Update

• src/model/option.rs (primary)
• src/error/options.rs (add error variants)
• Related test files

Estimated Effort

Medium (4-6 hours)

Dependencies

None

Related Issues

• Issue Implementation of the Binomial Model for Option Pricing #1: Reduce unwrap() in chains/chain.rs
• Issue Feature/draw binomial tree #2: Reduce unwrap() in greeks/equations.rs