Fix markdown preview restoring to wrong position on restart

extensions/markdown-language-features/preview-src/events.ts

@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 export function onceDocumentLoaded(f: () => void) {
-	if (document.readyState === 'loading' || document.readyState === 'uninitialized') {
+	if (document.readyState === 'loading' || document.readyState as string === 'uninitialized') {
 		document.addEventListener('DOMContentLoaded', f);
 	} else {
 		f();

extensions/markdown-language-features/preview-src/index.ts

@@ -19,7 +19,7 @@ const settings = getSettings();
 const vscode = acquireVsCodeApi();
 
 // Set VS Code state
-const state = getData('data-state');
+let state = getData('data-state');
 vscode.setState(state);
 
 const messaging = createPosterForVsCode(vscode);
@@ -152,6 +152,8 @@ if (settings.scrollEditorWithPreview) {
 			const line = getEditorLineNumberForPageOffset(window.scrollY);
 			if (typeof line === 'number' && !isNaN(line)) {
 				messaging.postMessage('revealLine', { line });
+				state.line = line;
+				vscode.setState(state);
 			}
 		}
 	}, 50));

extensions/markdown-language-features/preview-src/scroll-sync.ts

@@ -24,13 +24,13 @@ const getCodeLineElements = (() => {
 	let elements: CodeLineElement[];
 	return () => {
 		if (!elements) {
-			elements = ([{ element: document.body, line: 0 }]).concat(Array.prototype.map.call(
-				document.getElementsByClassName('code-line'),
-				(element: any) => {
-					const line = +element.getAttribute('data-line');
-					return { element, line };
-				})
-				.filter((x: any) => !isNaN(x.line)));
+			elements = [{ element: document.body, line: 0 }];
+			for (const element of document.getElementsByClassName('code-line')) {
+				const line = +element.getAttribute('data-line')!;
+				if (!isNaN(line)) {
+					elements.push({ element: element as HTMLElement, line });
+				}
+			}
 		}
 		return elements;
 	};

extensions/markdown-language-features/preview-src/tsconfig.json

@@ -6,6 +6,7 @@
 		"jsx": "react",
 		"sourceMap": true,
 		"strict": true,
+		"strictBindCallApply": true,
 		"noImplicitAny": true,
 		"noUnusedLocals": true
 	}