先核來源與已訂規則
本例把「你」的 UTF-8 拆成 [E4,BD]、[A0]。每段另開解碼器,會把碎段各當完整輸入。匯入須承接狀態,最後仍未成字就拒收。
| 紀錄 | 輸入 JSON |
|---|---|
| 原例輸入 | {"chunks":[[228,189],[160]]} |
比較兩條實際路徑
承接解碼才得一個「你」。逐段用 stream=true,末尾再完成;尾段缺字節會在這步被查出。
| 路徑 | 輸出 JSON |
|---|---|
| 錯誤路徑 | {"accepted":true,"text":"\uFFFD\uFFFD"} |
| 更正路徑 | {"accepted":true,"text":"你"} |
import {DatabaseSync} from 'node:sqlite';
import {TextDecoder} from 'node:util';
import {inflateSync} from 'node:zlib';
import {posix} from 'node:path';
import {createHash} from 'node:crypto';
const rows=(db,sql)=>db.prepare(sql).all().map(r=>({...r}));
const failed=(action)=>{try{action();return null;}catch(e){return {code:e.errcode??e.code??e.name};}};
import assert from 'node:assert/strict';
const run=function run(i,corrected=true){
try{
if(!corrected)return {accepted:true,text:i.chunks.map(b=>new TextDecoder().decode(Uint8Array.from(b))).join('')};
const decoder=new TextDecoder('utf-8',{fatal:true});let text='';
for(const chunk of i.chunks)text+=decoder.decode(Uint8Array.from(chunk),{stream:true});
return {accepted:true,text:text+decoder.decode()};
}catch{return {accepted:false,error:'incomplete-or-invalid-utf8'};}
};
const cases=[{"label":"misleading base","input":{"chunks":[[228,189],[160]]},"expected":{"accepted":true,"text":"\uFFFD\uFFFD"},"corrected":false},{"label":"corrected base","input":{"chunks":[[228,189],[160]]},"expected":{"accepted":true,"text":"你"},"corrected":true},{"label":"one complete chunk","input":{"chunks":[[228,189,160]]},"expected":{"accepted":true,"text":"你"},"corrected":true},{"label":"incomplete final chunk","input":{"chunks":[[228,189]]},"expected":{"accepted":false,"error":"incomplete-or-invalid-utf8"},"corrected":true}];
for(const test of cases){
const actual=run(test.input,test.corrected);
assert.deepEqual(actual,test.expected,test.label);
console.log(test.label,actual);
}
下次載入前核邊界
整塊輸入與分段結果一致;最後不足字節要拒收,不顯成貌似已修字。
| 情況 | 輸入 JSON | 預期輸出 JSON |
|---|---|---|
| 一塊完整 UTF-8 | {"chunks":[[228,189,160]]} | {"accepted":true,"text":"你"} |
| 尾字尚未完整 | {"chunks":[[228,189]]} | {"accepted":false,"error":"incomplete-or-invalid-utf8"} |
分段是否已證明來源編碼無效?
查看參考答案
不是,合起是有效字節,可解成「你」。問題是兩段之間丟了解碼狀態。