forEach未處理的拒絕錯誤

Question

我正在嘗試使用forEach迭代數組時處理拒絕。 這是問題所在：

module.exports = function (alert, level, subscribers, tagSubscribers, message_type) {
    return decrypt(config.slack_bot_token)
        .then(function (auth_token) {
            console.log('Dispatch got the token from kms');
            subscribers.forEach(function(subscriber){
                return makePostCall(alert, level, subscriber, tagSubscribers, message_type, auth_token);
            });
        })
        .catch(function (error) {
            console.error('Error during dispatch: ' + error);
            throw new Error(error);
        });
};

makePostCall返回一個resolve或reject並按照以下方式查找內容...

function makePostCall(alert, level, subscriber, tagSubscribers, message_type, auth_token) {
    return new Promise(function (resolve, reject) {
        const headers = ...
        const url = ...
        var payload = ...

        request.post({
            url: url,
            headers: headers,
            form: payload
        }, function (error, response, body) {
            if (!error && response.statusCode === 200 && JSON.parse(body).ok === true) {
                console.log('successfully published to Slack');
                return resolve();
            }
            else if (!error && response.statusCode === 200 && JSON.parse(body).ok === false) {
                console.error('Status is 200 but ok is false: ' + JSON.stringify(body));
                return reject(new Error(JSON.stringify(body)));
            }
            else {
                console.error('Status other than 200: ' + JSON.stringify(error));
                return reject(new Error(JSON.stringify(error)));
            }
        });
    });
}

現在，在運行單元測試時，我遇到很多未處理的拒絕錯誤

Unhandled rejection Error: {"status":404,"statusCode":404}
    at Request._callback (/Users/alnu/IdeaProjects/meghaduta-alerter-slack-lambda/lib/dispatchAlert.js:63:31)
    at self.callback (/Users/alnu/IdeaProjects/meghaduta-alerter-slack-lambda/node_modules/request/request.js:188:22)
    at emitOne (events.js:96:13)
    at Request.emit (events.js:188:7)
    at Request.onRequestError (/Users/alnu/IdeaProjects/meghaduta-alerter-slack-lambda/node_modules/request/request.js:884:8)
    at emitOne (events.js:96:13)
    at OverriddenClientRequest.emit (events.js:188:7)
    at /Users/alnu/IdeaProjects/meghaduta-alerter-slack-lambda/node_modules/nock/lib/request_overrider.js:212:11
    at _combinedTickCallback (internal/process/next_tick.js:73:7)
    at process._tickDomainCallback (internal/process/next_tick.js:128:9)

作為參考，我正在使用Bluebird for Promises。 我對Node＆Promises很陌生。 試圖使用異步/等待來避免這種混亂，但是Node6.10尚不支持。

Answer 1

實際上，沒有人在聽諾言。 他們只是被扔掉了。 在Promise.all()包裝promise應該可以解決您的問題。

module.exports = function (alert, level, subscribers, tagSubscribers, message_type) {
    return decrypt(config.slack_bot_token)
        .then(function (auth_token) {
            console.log('Dispatch got the token from kms');
            return Promise.all(subscribers.map(function(subscriber){
                return makePostCall(alert, level, subscriber, tagSubscribers, message_type, auth_token);
            }));
        })
        .catch(function (error) {
            console.error('Error during dispatch: ' + error);
            throw new Error(error);
        });
};