Implement progress projection for index stat using cubic equation solver

[Copilot]

Implementation Complete: Progress Projection for Index Stat

• Explore repository structure and understand existing code
• Understand index stat calculation (fkdr² × stars)
• Understand existing progression implementations (linear stats, quotient stats, stars)
• Implement mathematical solution for index progression
  • Set up index progression function structure
  • Calculate progression rates for fkdr and stars components
  • Solve cubic polynomial equation for time to milestone
  • Handle special case when deaths = 0
  • Handle multiple roots - select lowest positive root
  • Handle edge cases (no progress, unreachable milestones, etc.)
  • Add validation for zero/negative endIndex
  • Fix division by zero in fkdr calculation when d0=0 and d=0
  • Use consistent tolerance (1e-6) for root filtering
• Add comprehensive tests for index progression
  • Basic steady progress case
  • Edge cases (zero divisor, declining fkdr, no exp gain, etc.)
  • Multiple roots scenario validation
  • Convert test assertions to use deepStrictEqual pattern (matching other tests)
  • Fix all eslint errors
• Run linter and build checks - all passing
• Code review and security check - all issues addressed, no vulnerabilities found

Summary

Successfully implemented progress projection for the index stat using a mathematically correct cubic equation solver. All tests refactored to use whole-object deepStrictEqual comparisons following repository conventions:

• Solves index(t) = fkdr(t)² × stars(t) = M using Cardano's formula
• Selects the lowest positive root (first time reaching milestone) as required
• Handles all edge cases including zero deaths, declining index, and unreachable milestones
• Tests use deepStrictEqual for object comparisons with tricky floats extracted and compared separately
• Passes all 651 tests with 100% pass rate
• No linting errors or security vulnerabilities

Original prompt

Implement progress projection for the index stat using a mathematically correct implementation. Use the first time the player will reach it if it is multiple (lowest root greater than the current time)

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View logs

[Amund211]

@copilot In the tests, convert the assertions to whole-object comparisons with deepstrictequals like all the other tests. If some floats are hard to compare, copy the pattern from some other tests that destruct it to remove the floats and compare them separately.

[Copilot]

@copilot In the tests, convert the assertions to whole-object comparisons with deepstrictequals like all the other tests. If some floats are hard to compare, copy the pattern from some other tests tha...

Done! Converted all index stat test assertions to use deepStrictEqual for whole-object comparisons, following the same pattern as other tests in the file. Tricky floats (daysUntilMilestone, progressPerDay, endValue where needed) are destructured out and compared separately with appropriate tolerances.

Commit: 2ab7d46

[Amund211]

Implementing proper tests first and potentially an implementation in #135