#864 development constant tail bug extending obj

[kennethshsu]

Summary of Changes

I plan on starting over, and let me try test driven dev this time. Can you review the tests first? I would recommend comparing against #868

Related GitHub Issue(s)

#864

Additional Context for Reviewers

The tests are the same, with the exception of the two cases where the pattern extends beyond the tail.

My plan is actually to start over, because I did too much work trying to regroup the CDF, and that added a lot of tech debt. Please just review the tests for now.

• I passed tests locally for both code (uv run pytest) and documentation changes (uv run jb build docs --builder=custom --custom-builder=doctest)

---

Note

Low Risk
Test-only changes to development constant behavior specs; no runtime logic modified in this diff.

Overview
This PR expands test_constant.py with TDD coverage for DevelopmentConstant pattern handling (issue #864), without changing production code yet.

It reformats existing callable-axis tests and fixes the callable_axis=1 assertion to compare full patterns.values (not a truncated slice). test_constant_callable_axis1 is marked xfail until #864 lands.

New tests pin expected cdf_ / ldf_ when patterns are shorter than the triangle (no tail), on incremental triangles, and when patterns match, truncate, or extend past the development tail. Most of those scenarios are xfail with reason coming with #864; test_constant_pattern_no_tail and test_constant_incr run as passing specs today.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.30%. Comparing base (31b3432) to head (1666375).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #923      +/-   ##
==========================================
+ Coverage   88.28%   88.30%   +0.01%     
==========================================
  Files          88       88              
  Lines        5029     5029              
  Branches      642      642              
==========================================
+ Hits         4440     4441       +1     
+ Misses        444      443       -1     
  Partials      145      145              

Flag	Coverage Δ
unittests	88.30% <ø> (+0.01%)	⬆️

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[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[cursor]

Axis1 test drops ultimate column

Medium Severity

test_constant_callable_axis1 now compares fitted cdf_ values to all of patterns.values, but the pattern grid still includes the ultimate age column (value 1). The PR only intended to change tail-extension cases; this assertion should still exclude that column like patterns.values[:, :-1].

 

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