As an operator, I want to define a rectangular plateau by its upper-right corner coordinates, so that rovers have a bounded grid to navigate within.
Architecture Reference: 05-building-blocks.md — Plateau domain value object; 01-introduction.md — FR-1
Scenario ID: PLATEAU-STORY-001-S1
GIVEN
Upper-right corner coordinates 5 5 are provided
WHEN
A Plateau is constructed
THEN
The grid spans (0,0) to (5,5) inclusive
is_within(0, 0) returns True
is_within(5, 5) returns True
Scenario ID: PLATEAU-STORY-001-S2
GIVEN
A Plateau(5, 5) exists
WHEN
is_within(3, 2) is called
THEN
Returns True
Scenario ID: PLATEAU-STORY-001-S3
GIVEN
A Plateau(5, 5) exists
WHEN
is_within(6, 0) or is_within(-1, 3) is called
THEN
Returns False
Scenario ID: PLATEAU-STORY-001-S4
GIVEN
A Plateau(5, 5) has been created
WHEN
Any attempt is made to modify width or height
THEN
An exception is raised and dimensions remain unchanged
Story ID: PLATEAU-BE-001.1
As a developer I want an immutable Plateau value object so that boundary checks are reliable and side-effect-free.
Architecture Reference: 05-building-blocks.md — Plateau; 08-cross-cutting-concepts.md — immutability
Scenarios:
Scenario ID: PLATEAU-BE-001.1-S1
GIVEN
Plateau is implemented as a frozen dataclass
WHEN
A test attempts plateau.width = 10
THEN
A FrozenInstanceError (or equivalent) is raised
Mars Rover
mars_rover/domain/plateau.py¶from dataclasses import dataclass
@dataclass(frozen=True)
class Plateau:
"""Immutable rectangular grid. Lower-left is always (0, 0)."""
width: int
height: int
def is_within(self, x: int, y: int) -> bool:
return 0 <= x <= self.width and 0 <= y <= self.height
Design notes:
frozen=True enforces immutability (PLATEAU-STORY-001-S4, cross-cutting concept from 08-cross-cutting-concepts.md)
No I/O, no framework imports — pure domain object (TC-2)
is_within is the single boundary-check entry point used by MoveForward (see NAV-STORY-001)
tests/domain/test_plateau.py¶import pytest
from mars_rover.domain.plateau import Plateau
def test_plateau_contains_origin():
assert Plateau(5, 5).is_within(0, 0) is True
def test_plateau_contains_upper_right_corner():
assert Plateau(5, 5).is_within(5, 5) is True
def test_plateau_contains_interior_point():
assert Plateau(5, 5).is_within(3, 2) is True
def test_plateau_rejects_x_too_large():
assert Plateau(5, 5).is_within(6, 0) is False
def test_plateau_rejects_y_too_large():
assert Plateau(5, 5).is_within(0, 6) is False
def test_plateau_rejects_negative_x():
assert Plateau(5, 5).is_within(-1, 3) is False
def test_plateau_rejects_negative_y():
assert Plateau(5, 5).is_within(3, -1) is False
def test_plateau_is_immutable():
plateau = Plateau(5, 5)
with pytest.raises(Exception):
plateau.width = 10 # type: ignore[misc]
Story ID: PLATEAU-FE-001.1
As an operator I want to specify the plateau via plain-text stdin so that I can define the mission grid without a GUI.
Architecture Reference: 03-context.md — Operator → System interface; 07-deployment.md — single-process CLI
Scenarios:
Scenario ID: PLATEAU-FE-001.1-S1
GIVEN
The operator pipes a text file to the CLI
WHEN
The first line is 5 5
THEN
The system creates a Plateau(5, 5) and proceeds to parse rover blocks
No browser or GUI component required. The plateau is defined via stdin text (see CLI-STORY-001 — CLI pipe input).
Story ID: PLATEAU-INFRA-001.1
As a developer I want the plateau functionality to be containerized and testable so that plateau validation and boundary checking work consistently across environments.
Architecture Reference: 07-deployment.md — deployment topology; 02-constraints.md — TC-1
Scenario ID: PLATEAU-INFRA-001.1-S1
GIVEN
The Docker container includes plateau validation logic
Input contains plateau dimensions “5 5”
WHEN
The container processes the input
THEN
A Plateau(width=5, height=5) domain object is created
Plateau dimensions are validated as positive integers
The plateau is available for rover boundary checking
Scenario ID: PLATEAU-INFRA-001.1-S2
GIVEN
The Docker container includes input validation
Invalid plateau input “-1 5” is provided
WHEN
The container processes the input
THEN
Validation error is logged to stderr
Error message indicates invalid plateau dimensions
Container exits with non-zero exit code
No plateau object is created
Scenario ID: PLATEAU-INFRA-001.1-S3
GIVEN
The mars_rover/domain/plateau.py file exists
The Dockerfile includes domain code copying
WHEN
docker build -t mars-rover . is executed
THEN
The build includes plateau domain code at /app/mars_rover/domain/plateau.py
All plateau-related dependencies are installed
The container can import and use the Plateau class
Build completes without errors
Scenario ID: PLATEAU-INFRA-001.1-S4
GIVEN
Test files exist for plateau functionality in tests/domain/test_plateau.py
The Docker container includes pytest
WHEN
docker run --rm mars-rover pytest tests/domain/test_plateau.py -v is executed
THEN
All 8 plateau unit tests run inside the container
Tests validate plateau creation, boundary checking, and validation
pytest discovers and executes all plateau-related tests
Container exits with code 0 on test success
Plateau dataclass implemented in mars_rover/domain/plateau.py
All 8 unit tests pass (pytest tests/domain/test_plateau.py)
Container validates plateau dimensions from input correctly
Container logs validation errors for invalid plateau input
Dockerfile builds successfully with plateau domain code
Test suite runs inside container and validates plateau functionality
ruff, black, and isort pass with no warnings
No imports from adapters/ or application/ inside domain/