021-snake-game/docs/project-plan.md

Project Plan: Snake Game (Day 21)

Metadata

Key	Value
ID	PP-001
CrossReference	BC-001, SA-001, MIL-001, MIL-002, MIL-003
Language	en
Domain	it

Version History

Date	Status	Author	Reviewer	Change	Commit
2026-10-08	Deprecated	Jens Tirsvad Nielsen	S01	Sync applied: milestone links and issue numbers; description and topics set; open issues closed on S01's instruction in chat	f13d004
2026-10-08	Accepted	Jens Tirsvad Nielsen	S01	Closed the GitHub copy open issue: the copy already shows the description and topics, which this project did not set; closed on S01's instruction in chat	pending

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Purpose

This plan schedules the three milestones that deliver the Snake Game (Day 21) repository of BC-001 in one phase of about one week. The repository starts from the finished main of the day-20 repository 020-snake-game (commit 1a638c9), which already holds the game of days 20 and 21 with tests and documentation. The three milestones therefore adopt that base, check it against the day-21 lectures, and finish the repository. Each milestone is one gateway document, one branch and one pull request, so that every step is kept track of and reviewed before the next one starts.

Planning Assumptions

• The phase starts 2026-10-08 and ends by 2026-10-16, which leaves two days of buffer after MIL-003. All dates are proposed and need the Product Owner's confirmation (see Open Issues).
• Phase length: one to three days per milestone, sized for the spare time of S01, who owns every phase (SA-001).
• The starting point is the finished base, not the day-20 state. S01 chose this on 2026-10-08, in chat, after being told that the base already holds the day-21 features. The plan therefore does not rebuild the game in lecture order; it splits the work by activity: the foundation files (MIL-001), the game and its tests (MIL-002), and the check against the lectures (MIL-003).
• The base is copied file by file, so each adopted file is a task, and every difference from the base is listed in the pull request.
• One branch per milestone, named after it (mil-001-project-foundation, mil-002-adopt-the-game, mil-003-check-against-day-21), and one pull request that closes the issues of that milestone with one Closes #N line each.
• Nothing is committed, pushed or merged until S01 asks; S01 reviews the working tree first.
• The plan gate is enabled for commits in this clone (core.hooksPath is framework/githooks): a commit that changes src/ or tests/ needs a Task: MIL-NNN#N trailer for an accepted, reviewed milestone.

Gateway Schedule

Gateway	Document	Window	Decision date	Owner	Stories	Main deliverable	Milestone
Project foundation	MIL-001	2026-10-08 to 2026-10-09	2026-10-09	S01	None (see Open Issues)	pyproject.toml, .gitignore, constants.py, README, Doxyfile, continuous integration (CI) workflow, repository description and topics	milestone-88
Adopt the game	MIL-002	2026-10-10 to 2026-10-12	2026-10-12	S01	None (see Open Issues)	Snake, Food, Scoreboard, the main flow and python -m snake_game, with their tests and the README for the adopted game	milestone-89
Check against day 21	MIL-003	2026-10-13 to 2026-10-14	2026-10-14	S01	None (see Open Issues)	Comparison with the five day-21 lectures, corrections, finished README	milestone-90

@startgantt
Project starts 2026-10-08
[MIL-001 Project foundation] starts 2026-10-08 and ends 2026-10-09
[MIL-002 Adopt the game] starts 2026-10-10 and ends 2026-10-12
[MIL-003 Check against day 21] starts 2026-10-13 and ends 2026-10-14
[MIL-001 Go/No-Go] happens 2026-10-09
[MIL-002 Go/No-Go] happens 2026-10-12
[MIL-003 Go/No-Go] happens 2026-10-14
[Buffer] starts 2026-10-15 and ends 2026-10-16
@endgantt

Scope Coverage

Business Case scope item	Gateway
Adopting the finished game of the base: configuration, constants, workflow	MIL-001
Adopting the finished game of the base: Snake, Food, Scoreboard, the main flow and the tests	MIL-002
Day-21 lecture "Inheritance and slicing": Food and Scoreboard inherit from Turtle, the tail is a slice	MIL-002 (adopted), MIL-003 (checked)
Day-21 lecture "Detect collisions with food": the Food class, refresh, the eating distance	MIL-002 (adopted), MIL-003 (checked)
Day-21 lecture "Scoreboard": the Scoreboard class, increase_score, update_scoreboard	MIL-002 (adopted), MIL-003 (checked)
Day-21 lecture "Wall": the wall at 280 and the game-over text	MIL-002 (adopted), MIL-003 (checked)
Day-21 lecture "Tail": extend, add_segment and the tail check	MIL-002 (adopted), MIL-003 (checked)
Checking each rule against the lecture summaries and correcting the base	MIL-003
Constants in constants.py; src/, tests/, docs/ layout	MIL-001, corrected in MIL-003 where a value differs
pyproject.toml, Python .gitignore, Doxyfile, README, continuous integration workflow	MIL-001, README updated in MIL-002 and finished in MIL-003
Repository description and topics	MIL-001 (task 7), checked again in MIL-003

Dependencies

MIL-001 → MIL-002 → MIL-003

A No-Go on a gateway returns it to S01 for rework and moves every later date by the same number of days; the two buffer days absorb up to two days of slip before the end date 2026-10-16 moves.

Plan Risks

Risk	Impact	Mitigation
The planning documents take longer to review than the work left on the game	The first gateway slips	Review BC-001, SA-001, DICT-001 and this plan together in one sitting; keep the milestones small
Author and reviewer are the same person (S01)	A review can miss a defect	Use the Quality Criteria (QC) checklists and the pull request as the second look; recorded in BC-001
The git host has no Actions runner	The CI workflow is never executed	Run the same commands locally before each pull request; decide later whether a runner is needed
Lecture details are only available as the summaries in the request	The game differs from the video	S01 compares the finished game with the video at the MIL-003 Go/No-Go
The base was written against assumed day-21 numbers	MIL-003 finds differences late	The numbers are listed in the lecture-point table of MIL-003; a difference is corrected there with a test
The base and this repository hold the same code	A later fix reaches only one of them	Out of scope by decision (see BC-001); each pull request lists the differences from the base
The sync matches issues by title, so a title used twice overwrites an issue	A task disappears from the board	Every task title is unique across all milestones; check before each --apply

Open Issues

• Dates: the start date, milestone lengths and the end date 2026-10-16 are proposed and not given by the Product Owner; confirm or replace them.
• Product Owner (PO) language: the request is written in English, so en is recorded in docs/artifact-registry.md; the sections of every PO-language document follow it. Confirm, because a later change needs a new review of each document.
• Stakeholder levels: the Power and Interest levels of S02 and S03 in SA-001 are proposals, taken over from the day-20 repository.
• Starting point (closed by S01 on 2026-10-08): S01 chose the finished main of 020-snake-game as the base, not the day-20 state and not a rebuild.
• Repository address: the request names https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code (underscores), but origin of this clone is https://git.tirsystem.com/Tirsvad-Udemy-100-days-of-code/021-snake-game (hyphens). The plan uses the address of origin, where the repository exists. Confirm.
• Repository description and topics (closed by S01 on 2026-10-08): S01 confirmed the text proposed in the Deliverable of MIL-001 (a description and twelve topics, the same topics as the day-20 repository). It was set on the Gitea repository on 2026-10-08 with the Gitea API; criterion 9 of MIL-001 checks it.
• GitHub copy (closed by S01 on 2026-10-08): a GitHub copy of this repository exists next to the Gitea one. When it was checked on 2026-10-08 it showed the same description and topics as the Gitea repository. This project did not set them: S01 confirmed the text for the Gitea repository only. In the day-20 repository a workflow on the git host sets them, so this project does not touch the GitHub copy, and no task is added.
• "Python greater than 3.13": read as Python 3.13 or newer (requires-python = ">=3.13"); the machine of S01 has Python 3.13.14, which a strict "greater than 3.13" would exclude. Confirm.
• README template: the Product Owner's README template is used. It differs from framework/templates/README-template.md, whose section titles framework/scripts/check-readme.sh expects; that check is opt-in and stays off.
• Inheritance and display-free tests: the day-21 lectures teach class Food(Turtle), but a class that inherits from Turtle needs turtle (and so tkinter) at import time, unlike Snake. The base keeps the inheritance and has the tests install a fake turtle module before they import the classes, and main imports food and scoreboard only when it runs. Confirm, or ask for composition instead.
• Food under the snake: the lecture's refresh picks a random place without looking at the snake, and so does the base. Confirm, or ask for a place that is free.
• High score: no lecture of day 21 stores a high score; it is out of scope. Confirm.
• No user story or use case: the tasks are written as build and check steps, so they are plain technical tasks. If the player's goal (steer the snake) should be modelled, add a Use Case Diagram, a user story and a use case and reference them from the task rows.
• Governance and traceability matrix: GOV and TM do not exist yet. The review process asks for both (sign-off route and the "Last Reviewed" column). Decide whether to create them before the first review record is written.
• Diagram check: the Gantt chart above was not rendered because no PlantUML server is configured (PLANTUML_URL); render it before the review.
• Sync: done on 2026-10-08 with sync-project.sh --accepted-only --apply: Milestones 88 to 90 and Issues #1 to #22 exist on the git host (MIL-001: #1 to #7, MIL-002: #8 to #14, MIL-003: #15 to #22). The sync matches issues by title, so every task title must be unique across all milestones; they are. Run the sync again whenever a ## Tasks table changes. It used GITEA_TOKEN from the personal .env file, which the project never imports.

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