v0.6: real PNG textures (head with eyes, scaled body, corners, tapering tails, apple, board); renderPieces classifier + tests

tests/pieces.cjs

@@ -0,0 +1,68 @@
+// TDD: piece classification for textured rendering.
+// renderPieces(snake, dir) -> array of texture names, one per segment (head first).
+const assert = require('assert/strict')
+const fs = require('fs')
+const vm = require('vm')
+
+const src = fs.readFileSync(__dirname + '/../src/common/snake.js', 'utf8')
+const sandbox = { module: { exports: {} } }
+vm.runInNewContext(src, sandbox)
+const snake = sandbox.module.exports
+
+// compass sides: e/w/n/s (screen coords, y grows downward)
+function pieces(list, dir) { return snake.renderPieces(list, dir) }
+
+// -- initial snake: head east, horizontal body, tail pointing west
+assert.deepEqual(
+  pieces([{ x: 6, y: 7 }, { x: 5, y: 7 }, { x: 4, y: 7 }], { x: 1, y: 0 }),
+  ['head_e', 'body_h', 'tail_w'])
+
+// -- vertical snake moving south
+assert.deepEqual(
+  pieces([{ x: 3, y: 5 }, { x: 3, y: 4 }, { x: 3, y: 4 + 1 }], { x: 0, y: 1 })
+    .map((p, i) => i), // shape check below with explicit list instead
+  [0, 1, 2])
+assert.deepEqual(
+  pieces([{ x: 3, y: 5 }, { x: 3, y: 6 }, { x: 3, y: 7 }], { x: 0, y: 1 }),
+  ['head_s', 'body_v', 'tail_s'])
+
+// -- corner: head turned from east to south
+// snake [(6,8),(6,7),(5,7)]: neck connects south (to head) and west (to rest);
+// tail cell (5,7)'s neighbor is east, so its tip points west
+assert.deepEqual(
+  pieces([{ x: 6, y: 8 }, { x: 6, y: 7 }, { x: 5, y: 7 }], { x: 0, y: 1 }),
+  ['head_s', 'corner_sw', 'tail_w'])
+
+// -- corner: head turned from east to north
+assert.deepEqual(
+  pieces([{ x: 6, y: 6 }, { x: 6, y: 7 }, { x: 5, y: 7 }], { x: 0, y: -1 }),
+  ['head_n', 'corner_nw', 'tail_w'])
+
+// -- corner heading west turning south (es corner mirrored)
+// tail cell (5,7)'s neighbor is west, so its tip points east
+assert.deepEqual(
+  pieces([{ x: 4, y: 8 }, { x: 4, y: 7 }, { x: 5, y: 7 }], { x: -1, y: 0 }),
+  ['head_w', 'corner_es', 'tail_e'])
+
+// -- double corner (S shape): head moving south, west, then north —
+// hand-verified: every middle cell of this tight zigzag is a corner
+// [(6,8) head][ (6,7) sw ][ (5,7) en ][ (5,6) sw ][ (4,6) en ][ (4,5) tail ]
+assert.deepEqual(
+  pieces([{ x: 6, y: 8 }, { x: 6, y: 7 }, { x: 5, y: 7 }, { x: 5, y: 6 }, { x: 4, y: 6 }, { x: 4, y: 5 }], { x: 0, y: 1 }),
+  ['head_s', 'corner_sw', 'corner_en', 'corner_sw', 'corner_en', 'tail_n'])
+
+// -- every returned piece maps to a texture that must exist
+const TEX = ['head_e', 'head_w', 'head_n', 'head_s',
+  'body_h', 'body_v',
+  'corner_en', 'corner_es', 'corner_nw', 'corner_sw',
+  'tail_e', 'tail_w', 'tail_n', 'tail_s']
+const dirTex = __dirname + '/../src/common/tex'
+for (const p of TEX) {
+  assert.ok(fs.existsSync(dirTex + '/' + p + '.png'), 'missing texture ' + p)
+}
+
+// -- food + board textures
+assert.ok(fs.existsSync(dirTex + '/apple.png'), 'missing apple texture')
+assert.ok(fs.existsSync(dirTex + '/board.png'), 'missing board texture')
+
+console.log('PIECE CLASSIFICATION PASS')