java-toy-robot

Toy Robot Challenge — a Java 21 CLI that places and moves a robot on a 5×5 table.

Quick start

Run from stdin

mvn compile exec:java

Enter commands one per line (Robot Challenge spec). End input with a blank line.

PLACE 0,0,NORTH
MOVE
REPORT

Expected output: 0,1,NORTH

Non-interactive example:

printf 'PLACE 0,0,NORTH\nMOVE\nREPORT\n\n' | mvn -q compile exec:java

Run from a file

mvn compile exec:java -Dexec.args="commands.txt"

The file is read line-by-line until the first blank line (same rule as stdin). If no argument is given, the app reads from stdin.

Run tests

mvn test
# Tests run: 78, Failures: 0, Errors: 0, Skipped: 0

Architecture

flowchart LR
    Input[stdin or file] --> Parser[CommandParser]
    Parser --> CLI[TextInputInterface]
    CLI --> Simulator[RobotSimulator]
    Simulator --> Table[Table 5x5]
    Table --> Robot[Robot state]
    Simulator --> Output[REPORT output]

Loading

Layer	Package	Responsibility
CLI	com.andywong.cli	Parse command lines, read input, print REPORT
Application	com.andywong.application	Apply spec semantics (ignore invalid moves/placements)
Domain	com.andywong.domain	Table bounds, robot state, directions

Main entry point: com.andywong.cli.TextInputInterface

Refactor progress

Phases are tracked in docs/REFACTOR_ROADMAP.md. Summary:

Phase	Focus	Status
1	Build tooling, parsing, test isolation	Done — PR #2
2	Spec-aligned behavior, integration tests, file input	Done — PRs #4–#6
3	Clean architecture (no singletons, layered packages)	Done — PRs #8–#12
4	Polish (CI, edge-case tests, hardening)	Done — PRs #14–#17

Phase 4 — Polish

Slice	Change
4a	GitHub Actions CI (mvn test on push/PR)
4b	Parameterized edge-case tests (edges, corners, re-PLACE)
4d	README polish and CI badge
4c	CommandParseException and error-handling docs

Environment

• Java 21
• Maven 3.8+
• JUnit 5

Documentation

• Refactor roadmap — full phase plan and acceptance criteria
• Historical notes — pre–Phase 1 issues and root causes
• Error handling — which layers throw vs. ignore
• AGENTS.md — notes for cloud agents (stdin, main class, test count)
• Robot Challenge spec — official requirements