refactor(shim): Move node CustomEvent polyfill to Platform.shim (#357)

src/platform/deno.ts

@@ -105,7 +105,8 @@ Platform.load({
   Headers: globalThis.Headers,
   FormData: globalThis.FormData,
   File: globalThis.File,
-  ReadableStream: globalThis.ReadableStream
+  ReadableStream: globalThis.ReadableStream,
+  CustomEvent: globalThis.CustomEvent
 });
 
 export * from './lib.js';

src/platform/node.ts

@@ -17,6 +17,7 @@ import os from 'os';
 import fs from 'fs/promises';
 import { readFileSync } from 'fs';
 import DOMParser from './polyfills/server-dom.js';
+import CustomEvent from './polyfills/node-custom-event.js';
 import { fileURLToPath } from 'url';
 import evaluate from './jsruntime/jinter.js';
 
@@ -123,7 +124,8 @@ Platform.load({
   Headers: Headers as unknown as typeof globalThis.Headers,
   FormData: FormData as unknown as typeof globalThis.FormData,
   File: File as unknown as typeof globalThis.File,
-  ReadableStream: ReadableStream as unknown as typeof globalThis.ReadableStream
+  ReadableStream: ReadableStream as unknown as typeof globalThis.ReadableStream,
+  CustomEvent: CustomEvent as unknown as typeof globalThis.CustomEvent
 });
 
 export * from './lib.js';

src/platform/polyfills/node-custom-event.ts

@@ -0,0 +1,13 @@
+// See https://github.com/nodejs/node/issues/40678#issuecomment-1126944677
+export default class CustomEvent extends Event {
+  #detail;
+
+  constructor(type: string, options?: CustomEventInit<any[]>) {
+    super(type, options);
+    this.#detail = options?.detail ?? null;
+  }
+
+  get detail() {
+    return this.#detail;
+  }
+}

src/platform/web.ts

@@ -115,7 +115,8 @@ Platform.load({
   Headers: globalThis.Headers,
   FormData: globalThis.FormData,
   File: globalThis.File,
-  ReadableStream: globalThis.ReadableStream
+  ReadableStream: globalThis.ReadableStream,
+  CustomEvent: globalThis.CustomEvent
 });
 
 export * from './lib.js';