read from stdin

.editorconfig

@@ -0,0 +1,2 @@
+[*.js]
+indent_size = 2

wichteln.js

@@ -1,13 +1,13 @@
 #!/usr/bin/env node
 
-const fs = require('fs');
-const readline = require('readline');
-const nodemailer = require('nodemailer');
+const fs = require("fs");
+const readline = require("readline");
+const nodemailer = require("nodemailer");
 
 const mailer = nodemailer.createTransport({
   sendmail: true,
-    newline: 'unix',
-    path: '/usr/sbin/sendmail'
+  newline: "unix",
+  path: "/usr/sbin/sendmail"
 });
 
 function mail(email, name, pick) {
@@ -25,47 +25,54 @@ Viel Spaß
 Thomas
 
 Ps.: Bitte gebt nicht mehr als 5 Euro pro Geschenk aus!
-`,
-    }, (err, info) => {
+`
+    },
+    (err, info) => {
       console.log(info.envelope);
       console.log(info.messageId);
-    });
+    }
+  );
 }
 
 function read() {
   return new Promise((resolve, reject) => {
     const people = [];
     const rl = readline.createInterface({
-            input: fs.createReadStream('people.txt')
+      input: process.stdin
     });
 
-        rl.on('line', line => {
+    rl.on("line", line => {
       const [name, email, group] = line.split(/\s+/);
       people.push({ name, email, group });
     });
 
-        rl.on('error', reject);
+    rl.on("error", reject);
 
-        rl.on('close', () => {
+    rl.on("close", () => {
       resolve(people);
     });
   });
 }
 
-async function run() {
+const run = async () => {
   const people = await read();
 
+  if (!people || !people.length) {
+    throw new Error("input file empty");
+  }
+
   people.forEach(drawer => {
     let picked;
 
-        let pickable = people.filter(p =>
-            !p.picked
-            && drawer.name !== p.name
-            && (!drawer.group || drawer.group !== p.group)
+    let pickable = people.filter(
+      p =>
+        !p.picked &&
+        drawer.name !== p.name &&
+        (!drawer.group || drawer.group !== p.group)
     );
 
     if (pickable.length === 0) {
-            throw new Error('ohhh, noone left for ', drawer.name);
+      throw new Error("ohhh, noone left for ", drawer.name);
     }
 
     let pickIndex = Math.floor(Math.random() * pickable.length);
@@ -73,10 +80,12 @@ async function run() {
     pickable[pickIndex].picked = true;
   });
 
-
-    fs.writeFileSync('./picks.json', JSON.stringify(people.map(({name, pick}) => ({name, pick})), null, 4));
+  fs.writeFileSync(
+    `./picks.txt`,
+    people.map(({ name, pick }) => `${name} picked ${pick}`).join("\n")
+  );
 
   people.forEach(p => mail(p.email, p.name, p.pick));
-}
+};
 
 run();