Google Form转Discord Webhook失效 报错400(50006)求助

几年前从Github获取的代码，用于将Google Form提交内容通过Discord Webhook发送至指定频道，此前运行正常，数月前突然失效。提交表单时触发报错：

Exception: Request failed for https://discord.com returned code 400. Truncated server response: {"message": "Cannot send an empty message", "code": 50006}

相关代码：

const POST_URL = "https://discord.com/api/webhooks/1237046117418401842/WFieSt7WaMHYWxmf58U6Cvui3t2LWGV1sZffw-XhCG9d5v5PB39ot7FGLvhKu5KO4VMB";

function onSubmit(e) {
    const response = e.response.getItemResponses();
    let items = [];

    for (const responseAnswer of response) {
        const question = responseAnswer.getItem().getTitle();
        const answer = responseAnswer.getResponse();
        let parts = []

        try {
            parts = answer.match(/[\s\S]{1,1024}/g) || [];
        } catch (e) {
            parts = answer;
        }

        if (!answer) {
            continue;
        }

        for (const [index, part] of Object.entries(parts)) {
            if (index == 0) {
                items.push({
                    "name": question,
                    "value": part,
                    "inline": false
                });
            } else {
                items.push({
                    "name": question.concat(" (cont.)"),
                    "value": part,
                    "inline": false
                });
            }
        }
    }

    const options = {
        "method": "post",
        "headers": {
            "contentType": "application/json",
        },
        "payload": JSON.stringify({
            "content": "‌",
            "embeds": [{
                "title": "GotFA Application",
                "color": 33023, // This is optional, you can look for decimal colour codes at https://www.webtoolkitonline.com/hexadecimal-decimal-color-converter.html
                "fields": items,
                "footer": {
                    "text": "Some footer here"
                },
                "timestamp": new Date().toISOString()
            }]
        })
    };

    UrlFetchApp.fetch(POST_URL, options);
};

问题分析 #

1. Discord API规则变更：原代码中content字段使用了零宽空格字符来规避空消息检查，但Discord现在不再认可这种“伪空”内容，判定消息为空。
2. 空字段场景未处理：如果表单所有回答都被if (!answer)过滤（比如用户未填写任何内容），items数组为空，导致embed无有效字段，进一步触发空消息报错。
3. 潜在代码bug：catch块中直接将answer赋值给parts（可能是字符串），后续循环会因非数组类型出错，间接导致消息内容异常。

修复方案 #

修改后的代码：

const POST_URL = "https://discord.com/api/webhooks/1237046117418401842/WFieSt7WaMHYWxmf58U6Cvui3t2LWGV1sZffw-XhCG9d5v5PB39ot7FGLvhKu5KO4VMB";

function onSubmit(e) {
    const response = e.response.getItemResponses();
    let items = [];

    for (const responseAnswer of response) {
        const question = responseAnswer.getItem().getTitle();
        const answer = responseAnswer.getResponse();
        let parts = []

        try {
            parts = answer.match(/[\s\S]{1,1024}/g) || [];
        } catch (e) {
            parts = [answer]; // 转为数组，避免循环出错
        }

        if (!answer) {
            continue;
        }

        for (const [index, part] of Object.entries(parts)) {
            if (index == 0) {
                items.push({
                    "name": question,
                    "value": part,
                    "inline": false
                });
            } else {
                items.push({
                    "name": `${question} (cont.)`,
                    "value": part,
                    "inline": false
                });
            }
        }
    }

    // 处理无有效回答的情况
    if (items.length === 0) {
        items.push({
            "name": "无有效回答",
            "value": "表单提交但未填写任何内容",
            "inline": false
        });
    }

    const options = {
        "method": "post",
        "headers": {
            "Content-Type": "application/json", // 标准HTTP头键名
        },
        "payload": JSON.stringify({
            "content": "收到新的表单提交：", // 替换零宽空格为可见文本
            "embeds": [{
                "title": "GotFA Application",
                "color": 33023,
                "fields": items,
                "footer": {
                    "text": "Some footer here"
                },
                "timestamp": new Date().toISOString()
            }]
        })
    };

    UrlFetchApp.fetch(POST_URL, options);
};

关键修改点 #

• 将content字段的零宽空格替换为明确的提示文本，确保Discord识别为有效内容。
• 修正请求头键名为标准的Content-Type，符合HTTP规范。
• 添加空字段处理逻辑，当无有效回答时插入默认提示字段。
• 修复catch块的parts赋值，确保始终为数组类型，避免循环报错。

内容的提问来源于stack exchange，提问作者Virgo