added a little test script

app.js

@@ -1,8 +1,10 @@
 const { SerialPort } = require('serialport')
 const express = require('express')
-const app = express()
-const { init, translate, circle, rectangle, to, label } = require("./hpgl.js");
 const tmi = require('tmi.js');
+const { init, translate, circle, rectangle, to, label } = require("./hpgl.js");
+
+const distance = 3;
+const app = express()
 
 const client = new tmi.Client({
     channels: ['twitchplaysplotter']
@@ -57,14 +59,14 @@ app.listen(3000, () => {
     console.log(`Example app listening on port`)
 })
 
-client.on('message', (channel, tags, message, self) => {
-    const distance = 3;
 
-    console.log(`${tags['display-name']}: ${message}`);
+const parseMessage = (message) => {
 
     if (message.toLowerCase().startsWith("lb")) {
         var words = message.toLowerCase().replace("lb", "");
         toPlotter(label(words));
+    } else if (message.toLowerCase().startsWith("distance")) {
+
     } else {
         switch (message.toLowerCase()) {
             case 'init':
@@ -102,4 +104,25 @@ client.on('message', (channel, tags, message, self) => {
                 break;
         }
     }
+}
+
+client.on('message', (channel, tags, message, self) => {
+
+    console.log(`${tags['display-name']}: ${message}`);
+    parseMessage(message)
 });
+
+
+var testMessages = ['init','pu','pd','up','down','left','right','right','rectangle','circle','LBhaihai'];
+var testIndex = 0;
+var interval = setInterval(function () {
+    console.log("----- about to send a test message: ", testMessages[testIndex]);
+    parseMessage(testMessages[testIndex]);
+
+    if(testIndex < (testMessages.length - 1)) {
+        testIndex++;
+    } else {
+        console.log("completed the test")
+        clearInterval(interval);
+    }
+}, 1000);

hpgl.js

@@ -32,19 +32,20 @@ function circle(radius, resolution = 10) {
 }
 
 function clampPosition() {
+  console.log(`clampPosition: ${state.position.x} ${state.position.y}`)
   if (state.position.x > 100) {
-    console.log("in the borderland");
+    console.log("in the borderland up");
     state.position.x = 100;
   } else if (state.position.x < 0) {
-    console.log("in the borderland");
+    console.log("in the borderland down");
     state.position.x = 0;
   }
 
   if (state.position.y > 100) {
-    console.log("in the borderland");
+    console.log("in the borderland up");
     state.position.y = 100;
   } else if (state.position.y < 0) {
-    console.log("in the borderland");
+    console.log("in the borderland down");
     state.position.y = 0;
   }
 }

readme.md

@@ -13,5 +13,6 @@ the commands are right now
 - left (move left by {distance})
 - rectangle (draw a rectangle with the size of {distance})
 - circle (draw a rectangle with the size of {distance})
+- set the value for distance
 
 Also, there is the start of some state tracking and clamping to prevent the plotter from getting stuck. But again, untested.