Guard async toolbox/dialog callbacks against torn-down DOM / missing opts (BL-16574)

src/BloomBrowserUI/bookEdit/TextBoxProperties/TextBoxProperties.ts

@@ -152,12 +152,18 @@ export default class TextBoxProperties {
     }
     fillInLanguageNames() {
         get("editView/getBookLangs", (result) => {
-            document.getElementById("tbprop-lang1")!.innerText =
-                "(" + result.data.V + ")";
-            document.getElementById("tbprop-lang2")!.innerText =
-                "(" + result.data.N1 + ")";
-            document.getElementById("tbprop-lang3")!.innerText =
-                "(" + result.data.N2 + ")";
+            // This is an async callback: by the time getBookLangs returns, the dialog may
+            // already have been closed and these elements removed from the DOM. In that case
+            // getElementById returns null; bail rather than throw (Sentry BLOOM-DESKTOP-FFJ).
+            // Guard all three (not just the first): don't rely on an assumption about the
+            // order in which the dialog's elements are torn down.
+            const lang1 = document.getElementById("tbprop-lang1");
+            const lang2 = document.getElementById("tbprop-lang2");
+            const lang3 = document.getElementById("tbprop-lang3");
+            if (!lang1 || !lang2 || !lang3) return;
+            lang1.innerText = "(" + result.data.V + ")";
+            lang2.innerText = "(" + result.data.N1 + ")";
+            lang3.innerText = "(" + result.data.N2 + ")";
         });
     }
 

src/BloomBrowserUI/bookEdit/toolbox/readers/leveledReader/leveledReaderTool.tsx

@@ -33,9 +33,13 @@ export class LeveledReaderTool extends ToolboxToolReactAdaptor {
     public beginRestoreSettings(opts: string): JQueryPromise<void> {
         return beginInitializeLeveledReaderTool().then(() => {
             const restoreDone = $.Deferred<void>();
+            // opts can be undefined/null when the tool is activated for a book that has no
+            // saved leveled-reader settings. Guard before indexing so we fall through to the
+            // default-level path instead of throwing an unhandled promise rejection that
+            // aborts tool activation (Sentry BLOOM-DESKTOP-FFH).
             const leveledReaderState = (
-                opts as unknown as Record<string, string>
-            )["leveledReaderState"];
+                opts as unknown as Record<string, string> | undefined
+            )?.["leveledReaderState"];
             if (leveledReaderState) {
                 // The true passed here prevents re-saving the state we just read.
                 // One non-obvious implication is that simply opening a level-4 book