TEST: Fix existing tests

[mnshkw]

Summary

• This PR fixes and improves the existing test code in test/cdp.jl and test/runtests.jl.
  • independent of PR TEST: Add Santos (1999) Section 7.3 stochastic growth benchmark tests #62 (Test for the multidimensional-state stochastic optimal growth model based on Santos 1999 benchmark)

Changes

test/runtests.jl

• ea92243:
  • Add LQ to the import list from QuantEcon explicitly

test/test_cdp.jl

• ea92243:

  • Remove using QuantEcon from inside the @testset block due to namespace pollution
  • Replace QUantEcon.LQ(...) with LQ(...)

• 109efdb:

  • Remove s_star and x_star (dead code), unused variable sigma = 0.1, and replace hardcoded number to already-defined variable

• 9b24891 :

  • Add checks for initial value, path length, and full path (previously, only the final step was checked against the analytical path)
  • Replace the single-step isapprox check with a full-path element-wise max absolute error check using maximum(abs, ...) <= atol
  • Relax atol from 1e-5 to 1e-4 to account for interpolation error accumulated in simulate
    • The observed maximum absolute error across all four basis × method combinations was ~1.68e-5, which exceeds 1e-5 but is well within 1e-4
    • The tolerance 1e-4 provides a safety margin while remaining a meaningful numerical bound

• 4bbfe33:

  • Wrap the inner loop body in @testset "Test $method with $label basis" so that failures clearly identify which bases x method combination failed

Test Results

All tests are pass successfully (Pkg.test() passes locally).

Notes for Reviewers

All codes and documentation are written with assistance by LLMs

cc: @oyamad
Could you please review this PR? Thank you.

[Copilot]

Pull request overview

This PR fixes and cleans up existing tests in test/test_cdp.jl and test/runtests.jl. It addresses namespace pollution from using QuantEcon inside a @testset block, removes dead code, replaces hardcoded values with named variables, improves simulation path assertions, and wraps inner test loops in labeled @testset blocks for better failure diagnostics.

Changes:

• Move LQ import to runtests.jl's top-level using QuantEcon line and remove the inner using QuantEcon from the "LQ control" testset to avoid namespace pollution
• Enhance simulation tests: add checks for initial value and path length, replace single-endpoint check with full-path max absolute error check, and relax atol from 1e-5 to 1e-4 to account for interpolation error accumulation
• Clean up dead code (unused sigma, bare s_star, x_star expression) and replace hardcoded 3 with n_shocks variable; wrap inner loop body in labeled @testset blocks

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
test/runtests.jl	Add LQ to the explicit import list from QuantEcon
test/test_cdp.jl	Remove inner using QuantEcon, use bare LQ(...), add @testset labels, improve simulation assertions, remove dead code, use named variables

---

You can also share your feedback on Copilot code review. Take the survey.

[oyamad]

@mnshkw I made a few changes at https://github.com/QuantEcon/ContinuousDPs.jl/tree/mnshkw-test/fix-existing-tests
Merge this branch into yours.
(See QuantEcon/QuantEcon.jl#229)