來源格式與預期記錄
這是原創假設轉換例子。輸入限下列欄位的普通、無循環 JSON 形記錄,統一記錄格式及拒絕代碼由本例訂明。若換來源,先修改格式約定。
本例 L、W、H 各須有一項,以正安全整數毫米表示。欠軸、重複或未知標籤均拒絕。輸出固定為 lengthMm、widthMm、heightMm,來源排列先後不影響配對。
| 個案 | 輸入記錄(JSON) | 預期輸出(JSON) |
|---|---|---|
| 按軸標籤分配 | {"axes":[{"axis":"W","mm":20},{"axis":"H","mm":10},{"axis":"L","mm":30}]} | {"ok":true,"value":{"lengthMm":30,"widthMm":20,"heightMm":10}} |
| 拒絕重複軸 | {"axes":[{"axis":"L","mm":30},{"axis":"L","mm":20}]} | {"ok":false,"error":"AXIS_VALUE"} |
| 拒絕欠高度 | {"axes":[{"axis":"L","mm":30},{"axis":"W","mm":20}]} | {"ok":false,"error":"AXIS_MISSING"} |
在本機執行轉換
把完整例子以 JavaScript 模組在 Node.js 執行,內含純轉換函數、三個輸入及寫明的預期輸出,對不上便由斷言停止。拒絕個案回傳 ok=false 及代碼,不回傳半份統一記錄。
import assert from 'node:assert/strict';
function axisDimensions(i){
const fail=error=>({ok:false,error});if(!i||!Array.isArray(i.axes))return fail('AXIS_LIST');
const values={};
for(const a of i.axes){if(!a||!['L','W','H'].includes(a.axis)||Object.hasOwn(values,a.axis)||!Number.isSafeInteger(a.mm)||a.mm<=0)return fail('AXIS_VALUE');values[a.axis]=a.mm;}
if(!['L','W','H'].every(x=>Object.hasOwn(values,x)))return fail('AXIS_MISSING');
return {ok:true,value:{lengthMm:values.L,widthMm:values.W,heightMm:values.H}};
}
// Original synthetic cases; expected outputs are literal records.
const cases = [
{
"label": "Map axes by label",
"input": {
"axes": [
{
"axis": "W",
"mm": 20
},
{
"axis": "H",
"mm": 10
},
{
"axis": "L",
"mm": 30
}
]
},
"expected": {
"ok": true,
"value": {
"lengthMm": 30,
"widthMm": 20,
"heightMm": 10
}
}
},
{
"label": "Reject repeated axis",
"input": {
"axes": [
{
"axis": "L",
"mm": 30
},
{
"axis": "L",
"mm": 20
}
]
},
"expected": {
"ok": false,
"error": "AXIS_VALUE"
}
},
{
"label": "Reject missing height",
"input": {
"axes": [
{
"axis": "L",
"mm": 30
},
{
"axis": "W",
"mm": 20
}
]
},
"expected": {
"ok": false,
"error": "AXIS_MISSING"
}
}
];
for (const sample of cases) {
const actual = axisDimensions(sample.input);
assert.deepEqual(actual, sample.expected);
console.log(sample.label, JSON.stringify(actual));
}
判清邊界個案
陣列先 W=20、H=10,最後 L=30,哪個是長?
查看參考答案
長 30 mm、闊 20 mm、高 10 mm。長由 L 標籤決定,重複 L 不能代替欠缺的 H。