refactor: replace unsafe Number constructor with type-safe alternatives #7777

[Beutife]

Motivation

Remove usage of Number() constructor which is unsafe because:

• It accepts any as parameter, allowing invalid types without TypeScript errors
• Silently produces NaN when given invalid input
• Makes code prone to runtime errors

Description

Added

• bigintToNumber() utility function in @lodestar/utils
  • Validates bigint is within safe integer range
  • Throws descriptive errors instead of returning NaN
  • Provides compile-time type safety

Modified

• Replaced Number(bigint) with bigintToNumber(bigint)
• Replaced Number(string) with parseInt(string, 10)
• Fixed code formatting across multiple files

Closes #issue_number
#7771

Steps to test or reproduce

git checkout fix-number-constructor-clean
yarn install
yarn build
yarn lint

[gemini-code-assist]

Summary of Changes

Hello @Beutife, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refactors the codebase to eliminate the unsafe usage of the Number() constructor, which can lead to silent NaN values and runtime errors due to its loose type acceptance. By introducing a new bigintToNumber() utility function and consistently using parseInt() for string conversions, the changes significantly improve type safety, error handling, and overall code robustness, making the system more predictable and less prone to unexpected numerical issues.

Highlights

• New Utility Function: Introduced bigintToNumber() in @lodestar/utils for safe conversion of bigint to number, including validation for safe integer range and error throwing for invalid conversions.
• Type-Safe BigInt Conversion: Replaced direct Number(bigint) calls with the new bigintToNumber() utility across the codebase to enhance type safety and prevent silent NaN issues.
• Type-Safe String Conversion: Replaced Number(string) calls with parseInt(string, 10) to ensure explicit base conversion and safer handling of string-to-number parsing.
• Code Formatting: Applied consistent code formatting across multiple files, improving readability and maintainability.

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[gemini-code-assist]

Code Review

This pull request is a great step towards improving type safety by replacing the unsafe Number() constructor. The introduction of bigintToNumber for bigint conversions and the switch to parseInt for strings are excellent changes. My review focuses on ensuring the new parsing logic is as robust as possible. I've pointed out several instances where parseInt is used without a radix, which can lead to unexpected behavior. I've also noted a few minor code style issues. Overall, this is a valuable refactoring that enhances code quality.

[gemini-code-assist]

It's a good practice to always specify the radix for parseInt. Since epoch is a decimal number string, you should specify radix 10 to ensure correct parsing and avoid potential issues.

    epoch: parseInt(epoch, 10),

[codecov]

Codecov Report

❌ Patch coverage is 45.58824% with 37 lines in your changes missing coverage. Please review.
✅ Project coverage is 51.91%. Comparing base (13fb933) to head (137f8a5).

Additional details and impacted files

@@            Coverage Diff            @@
##           unstable    #8584   +/-   ##
=========================================
  Coverage     51.90%   51.91%           
=========================================
  Files           848      849    +1     
  Lines         65797    65817   +20     
  Branches       4795     4797    +2     
=========================================
+ Hits          34153    34166   +13     
- Misses        31575    31582    +7     
  Partials         69       69           

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