Convert snippet preview controller to TypeScript

Author: rossta

app/javascript/controllers/snippets/preview.js

@@ -0,0 +1,44 @@
+import { Controller } from '@hotwired/stimulus';
+
+import debug from '../../utils/debug';
+
+const console = debug('app:javascript:controllers:snippets:preview');
+
+export default class extends Controller {
+  // Make timeout type play nice with TypeScript
+  // based on https://donatstudios.com/TypeScriptTimeoutTrouble
+  private idleTimeout?: ReturnType<typeof setTimeout>;
+
+  static targets = ['source', 'previewButton'];
+
+  declare readonly hasSourceTarget: boolean;
+  declare readonly sourceTarget: HTMLInputElement;
+  declare readonly sourceTargets: HTMLInputElement[];
+
+  declare readonly hasPreviewButtonTarget: boolean;
+  declare readonly previewButtonTarget: HTMLInputElement;
+  declare readonly previewButtonTargets: HTMLInputElement[];
+
+  connect(): void {
+    console.log('Connect!');
+  }
+
+  disconnect(): void {
+    this.clearIdleTimeout();
+  }
+
+  clearIdleTimeout(): void {
+    if (this.idleTimeout) clearTimeout(this.idleTimeout);
+  }
+
+  preview = (): void => {
+    console.log('Start preview timer!');
+    this.clearIdleTimeout();
+    this.idleTimeout = setTimeout(this.clickPreviewButton, 500);
+  };
+
+  clickPreviewButton = (): void => {
+    console.log('Click preview button!');
+    this.previewButtonTarget.click();
+  };
+}