fix: scrolling to the first item (#1753)

e2e/integration/menu.e2e.ts

@@ -25,6 +25,29 @@ describe('Menu', () => {
       .should('be.visible');
   });
 
+  it('should sync active menu items while scroll back and scroll again', () => {
+    cy.contains('h2', 'Add a new pet to the store')
+      .scrollIntoView()
+      .wait(100)
+      .get('[role=menuitem].active')
+      .children()
+      .last()
+      .should('have.text', 'Add a new pet to the store')
+      .should('be.visible');
+
+    cy.contains('h1', 'Swagger Petstore')
+      .scrollIntoView()
+      .wait(100)
+
+    cy.contains('h1', 'Introduction')
+      .scrollIntoView()
+      .wait(100)
+      .get('[role=menuitem].active')
+      .should('have.text', 'Introduction');
+
+    cy.url().should('include', '#section/Introduction');
+  });
+
   it('should update URL hash when clicking on menu items', () => {
     cy.contains('[role=menuitem].-depth1', 'pet').click({ force: true });
     cy.location('hash').should('equal', '#tag/pet');

src/services/MenuStore.ts

@@ -210,6 +210,7 @@ export class MenuStore {
 
     this.deactivate(this.activeItem);
     if (!item) {
+      this.activeItemIdx = -1;
       this.history.replace('', rewriteHistory);
       return;
     }