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Frontmatter

id	15429
title	Add unit coverage for Neo.util.Matrix
state	Open
labels	enhancementhelp wantedgood first issuecontributor-experienceaitesting
assignees	[]
createdAt	Jul 18, 2026, 7:28 AM
updatedAt	Jul 28, 2026, 3:50 PM
githubUrl	https://github.com/neomjs/neo/issues/15429
author	neo-opus-ada
commentsCount	4
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
contentTrust
projected
quarantined	0
signals	[]
blockedBy	[]
blocking	[]

Add unit coverage for Neo.util.Matrix

Open Backlog/active-chunk-7 enhancementhelp wantedgood first issuecontributor-experienceaitesting

neo-opus-ada commented on Jul 18, 2026, 7:28 AM

👋 New to Neo.mjs? This is a great first issue.

src/util/Matrix.mjs is a small, self-contained matrix-math helper — 4×4 transform matrices for CSS matrix3d(), rotation generators, and matrix multiplication. It's pure functions and simple class methods: no DOM, no async, no framework internals to learn. Your task is to add a focused unit test that pins its behavior, following the pattern of the util specs already in the repo. It's a self-contained, satisfying way to make your first contribution — and you'll be adding real value: this util backs the transform/animation geometry, and it currently has zero test coverage.

What the code does

Neo.util.Matrix (src/util/Matrix.mjs, ~160 lines):

static rotateX(t) / rotateY(t) / rotateZ(t) — return a 4×4 rotation matrix (a plain array of arrays) for angle t, using Math.cos/Math.sin. Pure functions.
getElement(i, j) (and its shortcut e(i, j)) — returns the 1-indexed element (i, j), or null when the indices are out of bounds.
multiply(m) (and its shortcut x(m)) — computes this × m. Note the contract: it writes the result into the argument's items and returns the argument.
getTransformStyle() — emits the CSS matrix3d(...) string from a 4×4 matrix, each value at toFixed(10) precision.

Instances are created with Neo.create('Neo.util.Matrix', {items: [[...], ...]}).

How to get started

The sibling util specs are your template — look at test/playwright/unit/util/String.spec.mjs and test/playwright/unit/util/Function.spec.mjs. Copy the setup shape (the setup({appConfig}) + imports block) into a new test/playwright/unit/util/Matrix.spec.mjs.
Run the unit tests locally with npm run test-unit -- test/playwright/unit/util/Matrix.spec.mjs.
Write tests for each method (ideas below), open a PR, and you're done!

Acceptance Criteria

A new test/playwright/unit/util/Matrix.spec.mjs covering the static rotations, getElement/e, multiply/x, and getTransformStyle.
rotateX/Y/Z: identity matrix at t = 0, and the sin/cos placement is correct for a non-zero angle.
getElement: 1-indexed access returns the right element; out-of-bounds returns null.
multiply/x: verified against a hand-computed product (e.g. [[1,2],[3,4]] × [[5,6],[7,8]] = [[19,22],[43,50]]) — not by re-running the code and copying its output. Identity × M = M is a nice extra check.
getTransformStyle: the exact matrix3d(...) string for a known matrix (e.g. the 4×4 identity).
Tests pass: npm run test-unit -- test/playwright/unit/util/Matrix.spec.mjs.

Out of Scope

No change to src/util/Matrix.mjs itself — this is coverage only. (If a test happens to surface a real bug in the util, that's a separate issue — mention it in your PR and we'll take it from there.)

Good to know

Sibling coverage issues already completed by the community: Array (#15124), String (#15118), Json.extract (#15117). Questions are welcome — comment on this issue and a maintainer will help.

Parthiv2005 Jul 18, 2026, 10:02 PM

I'd like to work this one out

Parthiv2005 Jul 18, 2026, 11:03 PM

npm run test-unit fails on Windows x64 during webServer startup due to the chromadb ARM64-only binding bug. "Error: Process from config.webServer was not able to start. Exit code: 1"

2026-07-19T15:04:38Z @neo-gpt cross-referenced by #15576

@neo-gpt - 2026-07-19T15:05:48Z

Lane coordination

#15441 is the active Matrix implementation for this ticket: it opened at 2026-07-18T07:34:55Z, before @Parthiv2005's later interest signal at 20:02:42Z.

Its current state is bounded and recoverable:

exact head a7831aee54;
one formal CHANGES_REQUESTED review;
no head movement or author response yet;
a complete repair recipe is posted at https://github.com/neomjs/neo/pull/15441#issuecomment-5013564563 and was independently verified 7/7 green.

@Ap-0007: please reply with a simple continuing or yielding signal. If continuing, the linked comment is the shortest green path. If yielding, we can hand the ticket over without duplicate work.

@Parthiv2005: please do not start a competing Matrix spec while #15441 remains the first active implementation. This ownership collision is separate from your local setup failure, and it does not reduce our commitment to help:

We will help you get the unit runner working. Please post the complete failure output plus node -v, npm -v, and which shell you used (PowerShell, Command Prompt, Git Bash, or WSL). The current supported Windows route is WSL, but we will troubleshoot the concrete failure with you rather than dismissing it as an upstream problem.
If #15441 continues, we will offer you another good-first issue of comparable scope—or create a fresh one—so your interest still turns into a real contribution.

We will re-open this specific pickup explicitly if the first author yields or the PR is later dispositioned as inactive—never by silently racing two community contributors.

2026-07-19T18:21:44Z @neo-gpt cross-referenced by PR #15583

@Ap-0007 - 2026-07-28T13:50:33Z

Sorry to hear that npm run test-unit fails on Windows x64 for you. Could you please provide the complete failure output plus node -v, npm -v, and which shell you used? We'll troubleshoot this issue with you.