add auto-highlighting of selected/updated code

tests/unit/stubs/ApplicationStub.ts

@@ -13,10 +13,11 @@ export class ApplicationStub implements IApplication {
         return this;
     }
     public findCategory(categoryId: number): ICategory {
-        throw new Error('Method not implemented.');
+        return this.getAllCategories().find(
+            (category) => category.id === categoryId);
     }
     public getRecommendedScripts(): readonly IScript[] {
-        throw new Error('Method not implemented.');
+        throw new Error('Method not implemented: getRecommendedScripts');
     }
     public findScript(scriptId: string): IScript {
         return this.getAllScripts().find((script) => scriptId === script.id);

tests/unit/stubs/CategoryStub.ts

@@ -11,6 +11,14 @@ export class CategoryStub extends BaseEntity<number> implements ICategory  {
     constructor(id: number) {
         super(id);
     }
+
+    public getAllScriptsRecursively(): readonly IScript[] {
+        return [
+            ...this.scripts,
+            ...this.subCategories.flatMap((c) => c.getAllScriptsRecursively()),
+        ];
+    }
+
     public withScriptIds(...scriptIds: string[]): CategoryStub {
         for (const scriptId of scriptIds) {
             this.withScript(new ScriptStub(scriptId));

tests/unit/stubs/SelectedScriptStub.ts

@@ -0,0 +1,8 @@
+import { SelectedScript } from '@/application/State/Selection/SelectedScript';
+import { ScriptStub } from './ScriptStub';
+
+export class SelectedScriptStub extends SelectedScript {
+    constructor(id: string, revert = false) {
+        super(new ScriptStub(id), revert);
+    }
+}