Externalize EventEmitter3 dependency (RobotWebTools#688)

EzraBrooks · MatthijsBurgh · web-flow · commit bbe89a6300a4 · 2024-03-20T14:49:32.000-06:00
Co-authored-by: Matthijs van der Burgh &lt;MatthijsBurgh@outlook.com&gt;
diff --git a/examples/action_client.html b/examples/action_client.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <meta charset="utf-8" />
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
 <script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
diff --git a/examples/action_server.html b/examples/action_server.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <meta charset="utf-8" />
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
 <script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
diff --git a/examples/math.html b/examples/math.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <meta charset="utf-8" />
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
 <script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
diff --git a/examples/ros2_action_client.html b/examples/ros2_action_client.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <meta charset="utf-8" />
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
 <script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
diff --git a/examples/ros2_action_server.html b/examples/ros2_action_server.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <meta charset="utf-8" />
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
 <script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
diff --git a/examples/ros2_simple.html b/examples/ros2_simple.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <meta charset="utf-8" />
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
 <script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
diff --git a/examples/simple.html b/examples/simple.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <meta charset="utf-8" />
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
 <script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
diff --git a/examples/tf.html b/examples/tf.html
@@ -2,7 +2,8 @@
 <html>
 <head>
 <meta charset="utf-8" />
-<script src="../build/roslib.js"></script>
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
+<script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
   // Connecting to ROS
diff --git a/examples/urdf.html b/examples/urdf.html
@@ -2,7 +2,8 @@
 <html>
 <head>
 <meta charset="utf-8" />
-<script src="../build/roslib.js"></script>
+<script src="https://unpkg.com/eventemitter3@latest/dist/eventemitter3.umd.min.js"></script>
+<script src="../dist/RosLib.umd.cjs"></script>
 
 <script>
   /**
diff --git a/test/cdn-import.test.js b/test/cdn-import.test.js
@@ -0,0 +1,14 @@
+import { describe, it, expect } from 'vitest';
+import '../dist/RosLib.umd.cjs';
+import { readFileSync } from 'fs';
+import path from 'path';
+
+describe('Using as if imported from a CDN', () => {
+  it('Adds itself to the global namespace', () => {
+    expect(globalThis.ROSLIB).toBeTruthy();
+  })
+  it('Does not include EventEmitter in the bundle', () => {
+    // Read the bundled output of the file, check for `.on=function`, which is a reliable way to detect `EventEmitter.on` being defined.
+    expect(readFileSync(path.resolve(__dirname, '../dist/RosLib.umd.cjs')).includes('.on=function')).toBeFalsy();
+  })
+});
diff --git a/vite.config.js b/vite.config.js
@@ -27,7 +27,10 @@ export default defineConfig({
     rollupOptions: {
       // make sure to externalize deps that shouldn't be bundled
       // into your library
-      external: ['ws', 'src/util/decompressPng.js'],
+      external: ['eventemitter3', 'ws', 'src/util/decompressPng.js'],
+      output: {
+        globals: { eventemitter3: 'EventEmitter3' }
+      }
     },
   },
   test: {
