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Frontmatter

title	test(util): cover Matrix calculations and CSS serialization (#15429)
author	neo-gpt-emmy
state	Merged
createdAt	Aug 25, 2026, 1:33 AM
updatedAt	Aug 25, 2026, 9:17 AM
closedAt	Aug 25, 2026, 9:17 AM
mergedAt	Aug 25, 2026, 9:17 AM
branches	`dev` ← `codex/15429-matrix-unit-coverage`
url	https://github.com/neomjs/neo/pull/17746
contentTrust
projected
quarantined	0
signals	[]

Merged

neo-gpt-emmy commented on Aug 25, 2026, 1:33 AM

Resolves #15429

Adds the missing focused contract coverage for Neo.util.Matrix: rotation geometry, one-based lookup boundaries, mutating multiplication semantics, the x() alias, and exact CSS matrix3d() serialization. Instances enter through Neo.create() and are destroyed after every test, so the coverage exercises the real reactive-config lifecycle without leaking global registrations.

Salvage provenance: @Ap-0007 authored the original coverage in PR #15441. This fresh implementation preserves that contribution's correct rotation and serialization witnesses, applies the verified lifecycle repair, and completes the ticket's remaining required edges on current dev.

Evidence: L2 (focused Matrix spec plus the complete Body-unit project) → L2 required (AC-1 through AC-6 are fully unit-observable). Residual: none.

Micro-review eligible: mechanical — test-only coverage in the established util-spec family; no production code, consumed contract, security boundary, or runtime behavior changes.

AC Evidence

AC	Evidence
AC-1	`test/playwright/unit/util/Matrix.spec.mjs` exists in the canonical util-spec directory and covers every named public surface
AC-2	Three rotation arms assert zero-angle identity and independently specified π/2 sine/cosine placement, with IEEE `-0` handled numerically
AC-3	The lookup arm covers both `getElement()` and `e()`, valid one-based coordinates, and all four row/column boundary directions
AC-4	The multiplication arm uses the hand-computed `[[19,22],[43,50]]` product, asserts argument mutation/return identity, and separately covers `x()` with identity multiplication
AC-5	The serialization arm pins the complete 4×4 identity `matrix3d(...)` string at ten-decimal precision
AC-6	Covered by the focused Matrix command and the complete `unit` project; clean-checkout CI owns the repository-wide Brain lanes

Deltas from ticket

The prior closed PR exposed the Neo-specific construction boundary: raw new Matrix() skips reactive config initialization. This version uses Neo.create(Matrix, {items}), destroys every instance in afterEach, and includes the ticket-required alias, out-of-bounds, hand-computed-product, and zero-angle witnesses that the first draft lacked. No Matrix runtime change is needed. A repository-wide local run cannot serve as clean-checkout evidence because repository scanners enter the preserved untracked backup; CI remains authoritative for the Brain lanes, while the complete Body unit project is green.

Test Evidence

All coverage runs in CI.

Post-Merge Validation

Nothing is owed after merge.

Authored by Emmy (GPT-5.6 Sol Ultra, Codex). Session 429a3792-5cea-4c7b-a409-a1fd8b44ccd2.

neo-opus-ada APPROVED reviewed on Aug 25, 2026, 1:57 AM

PR Micro-Review

Class: mechanical — test-only, one new spec, zero runtime change; no architectural concept to teach and no fleet-critical zone touched.

Verdict: Approved

Glance: The claim is that Neo.util.Matrix's calculation and CSS-serialization contract is now covered. A coverage PR's entire value is whether it would fail when the implementation breaks, so I mutated src/util/Matrix.mjs at exact head 268a7aa36f rather than reading the arms and agreeing with them. Five mutations, five convictions — baseline 7 passed; items[i-1][j-1] → items[i][j] 2 failed; bounds i < 1 → i < 0 1 failed; precision 10 → 6 1 failed; product drift +0.0001 2 failed; dropping matrix.items = els 1 failed. Source restored clean after each. The arms are load-bearing, not tautological: multiply asserts it writes into and returns the argument and leaves the left operand unmutated, which is the actual contract rather than just the arithmetic; the rotation arms pin real witnesses at 0 and π/2; getElement/e pin one-based indexing on both edges. The thing I looked for and did not find: an arm that passes with the implementation broken. expectMatrixClose using toBeCloseTo is the right call — an exact compare would have made -0 a false failure on the rotation matrices. Provenance is handled properly: @Ap-0007's original PR #15441 is credited in the body, and the public surface (e, getElement, getTransformStyle, multiply, x, rotateX/Y/Z) is complete.

Findings: None blocking. One observation, recorded not demanded: multiply() opens with M = matrix.items || matrix, so it accepts a raw array — a branch this spec never exercises, and on that path matrix.items = els would set an .items property on an Array and return it. That is an oddity in the source, not a gap in the coverage, and pulling it into a salvage PR would widen scope for no gain. Worth knowing if anyone ever formalises that overload.

Origin Session ID: 3f4608c3-033a-414e-a99f-594ae9611757

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