FIX: Fix doctest

[genedan]

Summary of Changes

This is just a test (don't intend to merge) to see if the docstrings get picked up. Should be 252 tests instead of 109.

Related GitHub Issue(s)

1089

Additional Context for Reviewers

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

---

Note

Medium Risk
The WeightedRegression change to sigma_ affects Development/Mack stochastic outputs; new paper-reconciliation tests reduce but do not eliminate regression risk outside tested triangles.

Overview
Fixes documentation testing so CI generates Sphinx autosummary stubs before running Jupyter Book doctests, which lets many more docstring examples (including API stubs) execute in CI.

Docstring and doctest cleanup across Common (pipe, _validate_assumption), IBNR methods, ClarkLDF, and WeightedRegression—mostly expected outputs, testsetup/testoutput formatting, and clearer parameter docs so examples pass reliably.

WeightedRegression (origin-forced OLS path) now documents fit/average explicitly and changes how sigma_ is derived (sqrt(mse) instead of the prior Mack-style scaling). New Mack (1994/1997) hardcoded regression tests anchor sigma_ / IBNR SE behavior; test_sigma1 in development tests was removed.

Test coverage additions exercise Common._validate_assumption, set_backend (including nested Common / ldf_), and has_zeta / cum_zeta_.

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[github-actions]

Pyright Type Completeness

View the full pyright --verifytypes output for this commit

Project (full chainladder package, at this PR's head): 15.0% of exported symbols fully typed (191 / 1270)

	Known	Ambiguous	Unknown	Total
Project (head)	191	110	969	1270

Other symbols referenced but not exported by chainladder: 13

	Known	Ambiguous	Unknown	Total
Other (head)	3	1	9	13

Symbols without documentation:

• Functions without docstring: 310
• Functions without default param: 0
• Classes without docstring: 10

Patch (exported symbols added or changed by this PR): 23.3% fully typed (7 / 30); 1 no longer exported

	Known	Ambiguous	Unknown	Total
Patch	7	5	18	30

Patch symbol details

Symbol	Status	Change
chainladder.core.tests.test_triangle.test_cum_zeta_raises_when_no_zeta	❌ unknown	new
chainladder.core.tests.test_triangle.test_cum_zeta_returns_incr_to_cum	❌ unknown	new
chainladder.core.tests.test_triangle.test_has_zeta_false	❌ unknown	new
chainladder.core.tests.test_triangle.test_has_zeta_true	❌ unknown	new
chainladder.core.tests.test_triangle.test_set_backend_deep_propagates_to_nested_common	❌ unknown	new
chainladder.core.tests.test_triangle.test_set_backend_inplace_mutates_values	❌ unknown	new
chainladder.core.tests.test_triangle.test_set_backend_inplace_updates_array_backend_attr	❌ unknown	new
chainladder.core.tests.test_triangle.test_set_backend_invalid_raises	❌ unknown	new
chainladder.core.tests.test_triangle.test_set_backend_no_array_backend_raises	✅ known	new
chainladder.core.tests.test_triangle.test_set_backend_roundtrip	❌ unknown	new
chainladder.core.tests.test_triangle.test_set_backend_via_ldf	❌ unknown	new
chainladder.core.tests.test_triangle.test_validate_assumption_axis2	❌ unknown	new
chainladder.core.tests.test_triangle.test_validate_assumption_callable	❌ unknown	new
chainladder.core.tests.test_triangle.test_validate_assumption_dict	❌ unknown	new
chainladder.core.tests.test_triangle.test_validate_assumption_scalar	❌ unknown	new
chainladder.core.tests.test_triangle.test_validate_assumption_sequence	❌ unknown	new
chainladder.core.tests.test_triangle.test_validate_assumption_set	❌ unknown	new
chainladder.methods.tests.test_mack.test_mack1994_hardcode	❌ unknown	new
chainladder.methods.tests.test_mack.test_mack1997_hardcode	❌ unknown	new
chainladder.utils.weighted_regression.WeightedRegression.__init__	✅ known	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.average	✅ known	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.axis	✅ known	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.exponent_	⚠️ ambiguous	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.sigma_	⚠️ ambiguous	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.std_err_	⚠️ ambiguous	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.thru_orig	✅ known	changed (was ⚠️ ambiguous)
chainladder.utils.weighted_regression.WeightedRegression.w	⚠️ ambiguous	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.x	⚠️ ambiguous	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.xp	✅ known	changed (was ❌ unknown)
chainladder.utils.weighted_regression.WeightedRegression.y	✅ known	changed (was ❌ unknown)
chainladder.development.tests.test_development.test_sigma1	—	no longer exported (was ❌ unknown)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.76%. Comparing base (c45d10b) to head (b45ab45).
⚠️ Report is 16 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1091      +/-   ##
==========================================
+ Coverage   90.06%   90.76%   +0.69%     
==========================================
  Files          91       91              
  Lines        5287     5287              
  Branches      671      671              
==========================================
+ Hits         4762     4799      +37     
+ Misses        370      346      -24     
+ Partials      155      142      -13     

Flag	Coverage Δ
unittests	90.76% <100.00%> (+0.69%)	⬆️

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[kennethshsu]

I see 252 tests here, I think this is good.

[henrydingliu]

i'm going to use this branch to fix all the failing doctests

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[henrydingliu]

confirming that mack doctests are now passing

[henrydingliu]

@genedan since i merged in #1096 in here, can you review that PR first?