diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index 20fc6b75d3773..4fcba5f120ba2 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -407,9 +407,7 @@ function preLoadCss(cssUrl) {
             function loadSearch() {
                 if (!searchLoaded) {
                     searchLoaded = true;
-                    // @ts-expect-error
                     window.rr_ = data => {
-                        // @ts-expect-error
                         window.searchIndex = data;
                     };
                     if (!window.StringdexOnload) {
@@ -1277,13 +1275,11 @@ function preLoadCss(cssUrl) {
     }
 
     window.addEventListener("resize", () => {
-        // @ts-expect-error
         if (window.CURRENT_TOOLTIP_ELEMENT) {
             // As a workaround to the behavior of `contains: layout` used in doc togglers,
             // tooltip popovers are positioned using javascript.
             //
             // This means when the window is resized, we need to redo the layout.
-            // @ts-expect-error
             const base = window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE;
             const force_visible = base.TOOLTIP_FORCE_VISIBLE;
             hideTooltip(false);
@@ -1329,11 +1325,9 @@ function preLoadCss(cssUrl) {
      */
     function showTooltip(e) {
         const notable_ty = e.getAttribute("data-notable-ty");
-        // @ts-expect-error
         if (!window.NOTABLE_TRAITS && notable_ty) {
             const data = document.getElementById("notable-traits-data");
             if (data) {
-                // @ts-expect-error
                 window.NOTABLE_TRAITS = JSON.parse(data.innerText);
             } else {
                 throw new Error("showTooltip() called with notable without any notable traits!");
@@ -1341,14 +1335,15 @@ function preLoadCss(cssUrl) {
         }
         // Make this function idempotent. If the tooltip is already shown, avoid doing extra work
         // and leave it alone.
-        // @ts-expect-error
         if (window.CURRENT_TOOLTIP_ELEMENT && window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE === e) {
-            // @ts-expect-error
             clearTooltipHoverTimeout(window.CURRENT_TOOLTIP_ELEMENT);
             return;
         }
         window.hideAllModals(false);
-        const wrapper = document.createElement("div");
+        // use Object.assign to make sure the object has the correct type
+        // with all of the correct fields before it is assigned to a variable,
+        // as typescript has no way to change the type of a variable once it is initialized.
+        const wrapper = Object.assign(document.createElement("div"), {TOOLTIP_BASE: e});
         if (notable_ty) {
             wrapper.innerHTML = "<div class=\"content\">" +
                 // @ts-expect-error
@@ -1394,11 +1389,7 @@ function preLoadCss(cssUrl) {
             );
         }
         wrapper.style.visibility = "";
-        // @ts-expect-error
         window.CURRENT_TOOLTIP_ELEMENT = wrapper;
-        // @ts-expect-error
-        window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE = e;
-        // @ts-expect-error
         clearTooltipHoverTimeout(window.CURRENT_TOOLTIP_ELEMENT);
         wrapper.onpointerenter = ev => {
             // If this is a synthetic touch event, ignore it. A click event will be along shortly.
@@ -1433,19 +1424,15 @@ function preLoadCss(cssUrl) {
      */
     function setTooltipHoverTimeout(element, show) {
         clearTooltipHoverTimeout(element);
-        // @ts-expect-error
         if (!show && !window.CURRENT_TOOLTIP_ELEMENT) {
             // To "hide" an already hidden element, just cancel its timeout.
             return;
         }
-        // @ts-expect-error
         if (show && window.CURRENT_TOOLTIP_ELEMENT) {
             // To "show" an already visible element, just cancel its timeout.
             return;
         }
-        // @ts-expect-error
         if (window.CURRENT_TOOLTIP_ELEMENT &&
-            // @ts-expect-error
             window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE !== element) {
             // Don't do anything if another tooltip is already visible.
             return;
@@ -1468,24 +1455,20 @@ function preLoadCss(cssUrl) {
      */
     function clearTooltipHoverTimeout(element) {
         if (element.TOOLTIP_HOVER_TIMEOUT !== undefined) {
-            // @ts-expect-error
             removeClass(window.CURRENT_TOOLTIP_ELEMENT, "fade-out");
             clearTimeout(element.TOOLTIP_HOVER_TIMEOUT);
             delete element.TOOLTIP_HOVER_TIMEOUT;
         }
     }
 
-    // @ts-expect-error
+    /**
+     * @param {Event & { relatedTarget: Node }} event
+     */
     function tooltipBlurHandler(event) {
-        // @ts-expect-error
         if (window.CURRENT_TOOLTIP_ELEMENT &&
-            // @ts-expect-error
             !window.CURRENT_TOOLTIP_ELEMENT.contains(document.activeElement) &&
-            // @ts-expect-error
             !window.CURRENT_TOOLTIP_ELEMENT.contains(event.relatedTarget) &&
-            // @ts-expect-error
             !window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE.contains(document.activeElement) &&
-            // @ts-expect-error
             !window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE.contains(event.relatedTarget)
         ) {
             // Work around a difference in the focus behaviour between Firefox, Chrome, and Safari.
@@ -1507,30 +1490,22 @@ function preLoadCss(cssUrl) {
      *                          If set to `false`, leave keyboard focus alone.
      */
     function hideTooltip(focus) {
-        // @ts-expect-error
         if (window.CURRENT_TOOLTIP_ELEMENT) {
-            // @ts-expect-error
             if (window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE.TOOLTIP_FORCE_VISIBLE) {
                 if (focus) {
-                    // @ts-expect-error
                     window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE.focus();
                 }
-                // @ts-expect-error
                 window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE.TOOLTIP_FORCE_VISIBLE = false;
             }
-            // @ts-expect-error
             document.body.removeChild(window.CURRENT_TOOLTIP_ELEMENT);
-            // @ts-expect-error
             clearTooltipHoverTimeout(window.CURRENT_TOOLTIP_ELEMENT);
-            // @ts-expect-error
-            window.CURRENT_TOOLTIP_ELEMENT = null;
+            window.CURRENT_TOOLTIP_ELEMENT = undefined;
         }
     }
 
     onEachLazy(document.getElementsByClassName("tooltip"), e => {
         e.onclick = () => {
             e.TOOLTIP_FORCE_VISIBLE = e.TOOLTIP_FORCE_VISIBLE ? false : true;
-            // @ts-expect-error
             if (window.CURRENT_TOOLTIP_ELEMENT && !e.TOOLTIP_FORCE_VISIBLE) {
                 hideTooltip(true);
             } else {
@@ -1566,9 +1541,7 @@ function preLoadCss(cssUrl) {
             if (ev.pointerType !== "mouse") {
                 return;
             }
-            // @ts-expect-error
             if (!e.TOOLTIP_FORCE_VISIBLE && window.CURRENT_TOOLTIP_ELEMENT &&
-                // @ts-expect-error
                 !window.CURRENT_TOOLTIP_ELEMENT.contains(ev.relatedTarget)) {
                 // Tooltip pointer leave gesture:
                 //
@@ -1601,7 +1574,6 @@ function preLoadCss(cssUrl) {
                 // * https://www.nngroup.com/articles/tooltip-guidelines/
                 // * https://bjk5.com/post/44698559168/breaking-down-amazons-mega-dropdown
                 setTooltipHoverTimeout(e, false);
-                // @ts-expect-error
                 addClass(window.CURRENT_TOOLTIP_ELEMENT, "fade-out");
             }
         };
@@ -1707,8 +1679,7 @@ function preLoadCss(cssUrl) {
         if (isHelpPage) {
             const help_section = document.createElement("section");
             help_section.appendChild(container);
-            // @ts-expect-error
-            document.getElementById("main-content").appendChild(help_section);
+            nonnull(document.getElementById("main-content")).appendChild(help_section);
         } else {
             onEachLazy(document.getElementsByClassName("help-menu"), menu => {
                 if (menu.offsetWidth !== 0) {
@@ -1854,8 +1825,7 @@ function preLoadCss(cssUrl) {
         sidebarButton.addEventListener("click", e => {
             removeClass(document.documentElement, "hide-sidebar");
             updateLocalStorage("hide-sidebar", "false");
-            if (document.querySelector(".rustdoc.src")) {
-                // @ts-expect-error
+            if (window.rustdocToggleSrcSidebar) {
                 window.rustdocToggleSrcSidebar();
             }
             e.preventDefault();
diff --git a/src/librustdoc/html/static/js/rustdoc.d.ts b/src/librustdoc/html/static/js/rustdoc.d.ts
index 28852125fe17a..3ac10742e4152 100644
--- a/src/librustdoc/html/static/js/rustdoc.d.ts
+++ b/src/librustdoc/html/static/js/rustdoc.d.ts
@@ -28,6 +28,9 @@ declare global {
         currentTheme: HTMLLinkElement|null;
         /** Generated in `render/context.rs` */
         SIDEBAR_ITEMS?: { [key: string]: string[] };
+        /** Notable trait data */
+        NOTABLE_TRAITS?: { [key: string]: string };
+        CURRENT_TOOLTIP_ELEMENT?: HTMLElement & { TOOLTIP_BASE: HTMLElement };
         /** Used by the popover tooltip code. */
         RUSTDOC_TOOLTIP_HOVER_MS: number;
         /** Used by the popover tooltip code. */
@@ -93,6 +96,10 @@ declare global {
         pending_type_impls?: rustdoc.TypeImpls,
         rustdoc_add_line_numbers_to_examples?: function(),
         rustdoc_remove_line_numbers_from_examples?: function(),
+        /** JSON-encoded raw search index */
+        searchIndex: string,
+        /** Used in search index shards in order to load data into the in-memory database */
+        rr_: function(string),
     }
     interface HTMLElement {
         /** Used by the popover tooltip code. */
diff --git a/src/librustdoc/html/static/js/search.js b/src/librustdoc/html/static/js/search.js
index 42b87d562529b..bd9dfe4588935 100644
--- a/src/librustdoc/html/static/js/search.js
+++ b/src/librustdoc/html/static/js/search.js
@@ -5244,9 +5244,7 @@ if (typeof window !== "undefined") {
             // search.index/root is loaded by main.js, so
             // this script doesn't need to launch it, but
             // must pick it up
-            // @ts-ignore
             if (window.searchIndex) {
-                // @ts-ignore
                 window.rr_(window.searchIndex);
             }
         },
diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js
index c055eb0f8081d..40ab8be03c93d 100644
--- a/src/librustdoc/html/static/js/storage.js
+++ b/src/librustdoc/html/static/js/storage.js
@@ -117,7 +117,7 @@ function addClass(elem, className) {
  * Remove a class from a DOM Element. If `elem` is null,
  * does nothing. This function is idempotent.
  *
- * @param {Element|null} elem
+ * @param {Element|null|undefined} elem
  * @param {string} className
  */
 // eslint-disable-next-line no-unused-vars