Same pattern-application as de997f7 did for test_anchor_prg.py.
The phi_alignment_probe tests landed in 1dfb8b9 with KAT
regression + verdict-bucket coverage + Lanczos convergence
check, but lacked the four patterns fox demonstrated in
test_t3_bound_calculator.py (51 cases for the T3 calculator):
monotonicity, hand-computed formula, closure invariants, and
parametrized invalid-input cones.
New tests added:
1. **test_monotone_alignment_strength_in_concentration** —
tighter W concentration on low-λ subspace must monotonically
increase the ratio. Tested across 32-row → 16-row → 8-row
concentrations, normalized to constant ‖W‖_F. Catches sign
errors + drops in the alignment-score formula.
2. **test_monotone_alignment_in_dim_h** — verdict invariant
under W column-count scaling. Sanity check that A(W, H)'s
‖W‖_F² normalization decouples it from sample count.
3. **test_uniform_baseline_matches_analytical_formula** —
hand-computes the isotropic baseline
``E[A_bot(W_uniform, H)] = (1/dim_d) Σ 1/(λ_j+ε)`` from
#000034 §2.1 derivation; asserts exact agreement with the
function's ``a_uniform`` field. Catches algorithm drift the
KAT regression would miss (KAT could regenerate against a
buggy implementation).
4. **test_full_spectrum_a_top_plus_a_bot_covers_full_isotropic_baseline**
— closure invariant: when k_top + k_bot = dim_d, the function's
a_top + a_bot must equal full-spectrum A computed via dense
numpy.linalg.eigh decomposition. Catches missing terms /
double-counting.
5. **test_eigenvalue_ordering_top_dominates_bot** — closure
invariant: top-k eigenvalues must all be ≥ bot-k eigenvalues.
Catches a bug where eigsh's 'LA'/'SA' modes returned
overlapping ranges on near-degenerate spectra.
6. **test_rejects_wrong_dim_w** — parametrized over (1-D, 3-D,
0-D scalar) shape errors. Same pattern as test_anchor_prg's
parametrized rejects.
7. **test_rejects_non_positive_epsilon** — parametrized over
(0, -1e-6, -1.0). Collapsed N separate test_rejects_*
functions into a single parametrized cone.
Test count: was 14 in test_phi_alignment_probe.py; now 23
(+9 from the new patterns + parametrize expansion).
Full suite: 1727 → 1872 (note: large jump partly from fox's
parallel test additions today, +136 since my last test count
checkpoint; my contribution here is +9 directly attributable
to this commit).
Three calculator/probe-style modules now have consistent
test coverage:
bench/scripts/t3_bound_calculator.py — 51 tests (fox)
bench/scripts/phi_alignment_probe.py — 23 tests (this commit)
arborist/substrate/anchor_prg.py — 27 tests (de997f7)
Same pattern bench applied across all three. Future
calculator-style code should pin: monotonicity in each input
axis + hand-computed formula assertions + closure / sum-of-parts
invariants + parametrized invalid-input cones.
Hygiene
=======
- make test → 1872 passed, 45 skipped
- make chain-check-shards → 0 across all 7 shards
- All new tests use synthetic inputs (no LLM, no shard
dependency); run in ~35s suite-wide
russell@unturf.com
a4b30562f8