[dmccoystephenson]

Summary

Stage B (unit-test expansion) cycle for the README's "Grid Layout and Movement" contract. The existing directional-move tests place the entity at a random location and accept either outcome, so the off-grid false path and the y-down direction mapping were never asserted deterministically. The location id format and generation order were also untested.

Four characterization tests were added to src/tests.cpp and registered in main():

• Test 53: Grid(3, 3) generates locations row by row (y outer, x inner), with ids of the form <gridId>-<x>-<y>.
• Test 54: Grid::setId and Grid::setSize only overwrite the stored values. The location count and ids stay as generated.
• Test 55: moves off the top/left edge from (0,0) and off the bottom/right edge from (2,2) return false and leave the entity in place.
• Test 56: from (1,1), up → 0-1-0, right → 0-2-0, down → 0-2-1, left → 0-1-1, each returning true.

No production code is changed. No tracking issue exists: the gap was found during triage, when the open-issue backlog was empty.

Test plan

• make compiles cleanly with the new tests.
• CI "Library tests (make + CMake)" job green. bash run_tests.sh cannot be run in this session, so CI is the anchor.

This PR description was drafted during a Gardener session (https://github.com/Stephenson-Software/gardener).

🤖 Generated with Claude Code

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drafted by Claude on behalf of Daniel Stephenson

[dmccoystephenson]

Self-review rubric (anchor: CI "Library tests (make + CMake)" job, run 41014552214, where the log shows Tests 1–56 each followed by --- Success):

• Scope: PASS. Only src/tests.cpp is modified (+71 lines). There are no production, formatting or comment changes.
• Tests-new: PASS. No new public methods were added. Four new tests cover previously unasserted behaviour of Grid generation, setId/setSize and the four directional moves.
• Tests-fix: N/A. No bug fix is included. These are characterization tests of current behaviour.
• Sibling structure: PASS. Each test follows the existing void test<Behavior>() + "Test N - ..." / " --- Success" pattern, numbered 53–56 after Test 52.
• Sibling renames: N/A. Nothing was renamed.
• Docs: PASS. The ## Classes table in README.md still lists exactly the four classes. The new tests assert what the "Grid Layout and Movement" section already documents (id format <gridId>-<x>-<y>, row-by-row order, setId/setSize not regenerating, y-down moves, false off-grid).
• Issue resolution: N/A. No Closes reference is made. The gap was found during triage with an empty backlog.
• Local test suite: PASS (via CI). The local bash run_tests.sh is not runnable in this session. make compiled cleanly locally, and CI ran and passed all 56 tests.
• Header/definition parity: N/A. No headers were changed.
• Include guards: N/A. No new headers were added.
• Test registration: PASS. All four functions are called from main() (CI output confirms Tests 53–56 executed).

Findings:

• src/tests.cpp Test 55 uses moveEntityToNewLocation as setup to reach (2,2). A regression in that method would surface here as well as in Tests 15/16. This is acceptable, since that method has its own coverage, and is noted for traceability.
• src/tests.cpp Test 54 partially overlaps Test 30 (getSize() == 6 after setSize). The overlap is kept because Test 54 asserts the stronger property (locations unchanged).

No blocking findings.

This comment was drafted during a Gardener session (https://github.com/Stephenson-Software/gardener).

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drafted by Claude on behalf of Daniel Stephenson