feat(js): m03 rules with fixtures and tests

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
This commit is contained in:
Lucas Winther
2026-10-28 23:41:34 +01:00
co-authored by Claude Sonnet 5.5
parent e9c41fed03
commit 2e39f23bb3
7 changed files with 1570 additions and 0 deletions
+716
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@@ -0,0 +1,716 @@
{
"function": "advance",
"cases": [
{
"name": "advance-plain-move",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 3,
"y": 2
},
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "advance-moves-in-nextDir-and-records-it-as-dir",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 1
},
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
}
],
"dir": "Up",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "advance-keeps-apple-it-did-not-reach",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": {
"x": 4,
"y": 4
},
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 3,
"y": 2
},
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": {
"x": 4,
"y": 4
},
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "advance-eat-grows-scores-clears-apple",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": {
"x": 3,
"y": 2
},
"seed": 1,
"score": 4,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 3,
"y": 2
},
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 5,
"status": "Playing",
"frame": 0
}
},
{
"name": "advance-into-wall-is-game-over",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 4,
"y": 2
},
{
"x": 3,
"y": 2
},
{
"x": 2,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 4,
"y": 2
},
{
"x": 3,
"y": 2
},
{
"x": 2,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "GameOver",
"frame": 0
}
},
{
"name": "advance-into-top-wall-records-turn",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 0
},
{
"x": 2,
"y": 1
},
{
"x": 2,
"y": 2
}
],
"dir": "Up",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 0
},
{
"x": 2,
"y": 1
},
{
"x": 2,
"y": 2
}
],
"dir": "Up",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "GameOver",
"frame": 0
}
},
{
"name": "advance-into-own-body-is-game-over",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 3,
"y": 2
},
{
"x": 3,
"y": 3
},
{
"x": 2,
"y": 3
},
{
"x": 1,
"y": 3
}
],
"dir": "Left",
"nextDir": "Down",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 3,
"y": 2
},
{
"x": 3,
"y": 3
},
{
"x": 2,
"y": 3
},
{
"x": 1,
"y": 3
}
],
"dir": "Down",
"nextDir": "Down",
"apple": null,
"seed": 1,
"score": 0,
"status": "GameOver",
"frame": 0
}
},
{
"name": "advance-into-vacating-tail",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 1,
"y": 1
},
{
"x": 1,
"y": 2
},
{
"x": 2,
"y": 2
},
{
"x": 2,
"y": 1
}
],
"dir": "Up",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 1
},
{
"x": 1,
"y": 1
},
{
"x": 1,
"y": 2
},
{
"x": 2,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "advance-into-tail-while-eating",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 1,
"y": 1
},
{
"x": 1,
"y": 2
},
{
"x": 2,
"y": 2
},
{
"x": 2,
"y": 1
}
],
"dir": "Up",
"nextDir": "Right",
"apple": {
"x": 2,
"y": 1
},
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 1,
"y": 1
},
{
"x": 1,
"y": 2
},
{
"x": 2,
"y": 2
},
{
"x": 2,
"y": 1
}
],
"dir": "Right",
"nextDir": "Right",
"apple": {
"x": 2,
"y": 1
},
"seed": 1,
"score": 0,
"status": "GameOver",
"frame": 0
}
},
{
"name": "advance-paused-unchanged",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Paused",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Paused",
"frame": 0
}
},
{
"name": "advance-game-over-unchanged",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "GameOver",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "GameOver",
"frame": 0
}
},
{
"name": "advance-won-unchanged",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Won",
"frame": 0
}
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Won",
"frame": 0
}
}
]
}
+250
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{
"function": "inBounds",
"cases": [
{
"name": "top-left-corner",
"args": [
{
"width": 20,
"height": 20,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
{
"x": 0,
"y": 0
}
],
"expected": true
},
{
"name": "bottom-right-corner",
"args": [
{
"width": 20,
"height": 20,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
{
"x": 19,
"y": 19
}
],
"expected": true
},
{
"name": "x-negative",
"args": [
{
"width": 20,
"height": 20,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
{
"x": -1,
"y": 0
}
],
"expected": false
},
{
"name": "y-negative",
"args": [
{
"width": 20,
"height": 20,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
{
"x": 0,
"y": -1
}
],
"expected": false
},
{
"name": "x-equals-width",
"args": [
{
"width": 20,
"height": 20,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
{
"x": 20,
"y": 5
}
],
"expected": false
},
{
"name": "y-equals-height",
"args": [
{
"width": 20,
"height": 20,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
{
"x": 5,
"y": 20
}
],
"expected": false
},
{
"name": "middle",
"args": [
{
"width": 20,
"height": 20,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
{
"x": 10,
"y": 10
}
],
"expected": true
}
]
}
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{
"function": "move",
"cases": [
{
"name": "move-up",
"args": [
{
"x": 3,
"y": 3
},
"Up"
],
"expected": {
"x": 3,
"y": 2
}
},
{
"name": "move-down",
"args": [
{
"x": 3,
"y": 3
},
"Down"
],
"expected": {
"x": 3,
"y": 4
}
},
{
"name": "move-left",
"args": [
{
"x": 3,
"y": 3
},
"Left"
],
"expected": {
"x": 2,
"y": 3
}
},
{
"name": "move-right",
"args": [
{
"x": 3,
"y": 3
},
"Right"
],
"expected": {
"x": 4,
"y": 3
}
},
{
"name": "move-does-not-wrap-at-the-edge",
"args": [
{
"x": 0,
"y": 0
},
"Up"
],
"expected": {
"x": 0,
"y": -1
}
}
]
}
+453
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{
"function": "turn",
"cases": [
{
"name": "turn-normal-perpendicular",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
"Up"
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "turn-same-direction-is-fine",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
"Right"
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "turn-reverse-rejected",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
"Left"
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "turn-replaces-pending-turn",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
"Down"
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Down",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "turn-against-last-moved-dir",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
},
"Left"
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Up",
"apple": null,
"seed": 1,
"score": 0,
"status": "Playing",
"frame": 0
}
},
{
"name": "turn-ignored-when-paused",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Paused",
"frame": 0
},
"Up"
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Paused",
"frame": 0
}
},
{
"name": "turn-ignored-when-game-over",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "GameOver",
"frame": 0
},
"Up"
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "GameOver",
"frame": 0
}
},
{
"name": "turn-ignored-when-won",
"args": [
{
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Won",
"frame": 0
},
"Up"
],
"expected": {
"width": 5,
"height": 5,
"snake": [
{
"x": 2,
"y": 2
},
{
"x": 1,
"y": 2
},
{
"x": 0,
"y": 2
}
],
"dir": "Right",
"nextDir": "Right",
"apple": null,
"seed": 1,
"score": 0,
"status": "Won",
"frame": 0
}
}
]
}
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// m03 rules: the pure game rules. Each function takes a state and returns a new one.
import { contains, dropLast } from './util.js'
import { pointEquals, point, delta, opposite } from './model.js'
/** The cell one step from `p` in direction `dir`. No wrapping: it may land outside the board. */
export const move = (p, dir) => {
const d = delta(dir)
return point(p.x + d.x, p.y + d.y)
}
/** True if `p` lies on the board. */
export const inBounds = (state, p) => p.x >= 0 && p.x < state.width && p.y >= 0 && p.y < state.height
/**
* Ask to turn. We compare with `dir` (where the snake last moved), not `nextDir`:
* otherwise Up-then-Left within one tick would turn a Right-moving snake back onto itself.
*/
export const turn = (state, dir) =>
state.status === 'Playing' && dir !== opposite(state.dir) ? { ...state, nextDir: dir } : state
/** One step of the game. */
export const advance = (state) => {
if (state.status !== 'Playing') return state
const d = state.nextDir
const head = move(state.snake[0], d)
const eating = state.apple !== null && pointEquals(head, state.apple)
// When not eating, the tail leaves its cell this step, so the head may move into it.
const body = eating ? state.snake : dropLast(state.snake)
return !inBounds(state, head) || contains(body, head, pointEquals)
? { ...state, dir: d, status: 'GameOver' }
: {
...state,
snake: [head, ...body],
dir: d,
apple: eating ? null : state.apple,
score: state.score + (eating ? 1 : 0),
}
}
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import { todo } from './todo.js'
/** The cell one step from `p` in direction `dir`. No wrapping: it may land outside the board. */
export const move = (p, dir) => todo('m03')
/** True if `p` lies on the board: `0 <= x < width` and `0 <= y < height`. */
export const inBounds = (state, p) => todo('m03')
/**
* Ask to turn the snake. Returns `state` unchanged unless the game is 'Playing' and
* `dir` is not the opposite of `state.dir` (the direction the snake last *moved*, not `nextDir`).
* Otherwise sets `nextDir = dir`. Several turns in one tick: the last allowed one wins.
*/
export const turn = (state, dir) => todo('m03')
/**
* One step of the game. Returns `state` unchanged unless 'Playing'. Otherwise the head moves in `nextDir`
* (which becomes `dir`):
* - head lands on the apple: the snake grows (tail kept), score + 1, apple becomes null;
* - otherwise the tail cell is vacated, so the head may enter the cell the tail is leaving;
* - head off the board, or onto a remaining body cell: status 'GameOver', snake unchanged (but `dir` updated).
*/
export const advance = (state) => todo('m03')
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import test from 'node:test'
import assert from 'node:assert/strict'
import { move, inBounds, turn, advance } from '../src/rules.js'
import { loadFixture, freeze } from './helpers.js'
const fixtureTests = (name, f) => {
const fx = loadFixture(name)
fx.cases.forEach((c) =>
test(`m03 ${fx.function}: ${c.name}`, () => assert.deepStrictEqual(f(...freeze(c.args)), c.expected)))
}
fixtureTests('m03-move', move)
fixtureTests('m03-in-bounds', inBounds)
fixtureTests('m03-turn', turn)
fixtureTests('m03-advance', advance)