Firebase cloud function for Slack button actions in medium article https://medium.com/evenbit/151c1c98641d

sendPingPongScore.ts

async function sendPingPongScore(pingId: string) {
    const payload = {attachments: []};
    const ping = (await admin.database().ref("ping").child(pingId).once("value")).val();
    const snap = await admin.database().ref("pong").orderByChild("ping").equalTo(pingId).limitToFirst(3).once("value");

    const medalColors = ["#C98910", "#A8A8A8", "#965A38"];
    let counter = 0;
    snap.forEach((childSnap) => {
        const pong = childSnap.val() as Pong;
        const color = medalColors[counter];
        counter += 1;

        payload.attachments.push({
            "fallback": "No ping pong scores for you today.",
            "color": color,
            "title": `#${counter} <@${pong.user_id}|${pong.user_name}>`,
            "fields": [
                {
                    "title": "Pong at",
                    "value": (new Date(pong.ponged_at)).toString(),
                    "short": true
                },
                {
                    "title": "Response time",
                    "value": `${pong.ping_pong_time/1000} seconds`,
                    "short": true
                }
            ]
        });

    });


    const installationRef = admin.database().ref("installations").child(ping.team);
    const installation = (await installationRef.once("value")).val();
    return rp({
        uri: installation.webhook.url,
        method: "POST",
        json: true,
        body: payload
    });
}