[Valyrian-Code]

Description

The existing r.plane testsuite only checks that the output raster exists; it
never verifies the computed values (and it needs the NC sample dataset). This
adds a pytest module that asserts the actual plane geometry on a small synthetic
XY region (no sample dataset required):

• A 45-degree plane dipping east through the origin gives z == easting at every
  cell.
• A horizontal plane (dip=0) equals the given elevation everywhere.

Motivation and context

r.plane computes a tilted plane from a dip, azimuth, and a point; that math was
untested. These assertions pin the geometry so a regression in the computation
would be caught.

How has this been tested?

pytest scripts/r.plane/tests/r_plane_test.py — 2 tests pass. Values were
confirmed against the running tool (r.out.xyz). ruff format and ruff check
are clean.

Types of changes

• Tests

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds automated tests for r.plane to validate core plane-generation behaviors in a small synthetic region.

Changes:

• Introduces a new pytest test module for r.plane.
• Adds coverage for a 45° east-dipping plane and a horizontal (dip=0) plane.
• Adds a small helper to parse r.out.xyz output for assertions.

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[RAJVEER42]

The failing macOS check here is unrelated to this PR. It is the flaky r.sim.water test_nodxdy (a stochastic, parallel SIMWE simulation — the test notes that parallelization affects the random number generator, and the failure is a tiny stochastic difference). This PR only adds tests for r.plane and does not touch r.sim.water; the same test passed on my other PRs from the same base. Could a maintainer re-run the failed job? Thanks!

[petrasovaa]

Use r.stats with format=json instead of r.out.xyz parsing.
Seems the gunittest test can be dropped, no need to duplicate.

[Valyrian-Code]

Thanks Anna, done both:

• The tests now use r.stats with format=json instead of parsing r.out.xyz, so there is no manual text parsing (the .json result is read directly with flags="gn").
• Dropped the old gunittest (testsuite/test_r_plane.py); it only checked that the output map exists, which the value tests already cover.

Verified both tests pass locally.