diff --git a/.vscode/settings.json b/.vscode/settings.json
index 2c1485213..c3749ad98 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -27,6 +27,7 @@
     "**/src/**/*.spec.ts": "typescriptreact"
   },
   "git.enableCommitSigning": true,
+  "prettier.prettierPath": "./node_modules/prettier",
   "editor.codeLens": true,
   "editor.formatOnSave": true,
   "editor.codeActionsOnSave": {
diff --git a/playwright/cps-ui-kit/components/cps-tree-select.spec.ts b/playwright/cps-ui-kit/components/cps-tree-select.spec.ts
new file mode 100644
index 000000000..c1f1d925c
--- /dev/null
+++ b/playwright/cps-ui-kit/components/cps-tree-select.spec.ts
@@ -0,0 +1,262 @@
+import { test, expect, type Page, type Locator } from '@playwright/test';
+
+function example(page: Page, testId: string): Locator {
+  return page.getByTestId(testId);
+}
+
+async function open(wrapper: Locator): Promise<void> {
+  await wrapper.getByTestId('cps-treeselect-box').click();
+}
+
+test.describe('cps-tree-select', () => {
+  test.beforeEach(async ({ page }) => {
+    await page.goto('/tree-select');
+  });
+
+  test.describe('Real keyboard navigation', () => {
+    test('ArrowDown moves real focus between real treeitems', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'required-tree-select');
+      await open(wrapper);
+
+      const attr2 = page.getByRole('treeitem', { name: 'Attr2_2' });
+      const attr3 = page.getByRole('treeitem', { name: 'Attr3_2' });
+      await attr2.focus();
+
+      await page.keyboard.press('ArrowDown');
+      await expect(attr3).toBeFocused();
+    });
+
+    test('Escape closes the real dropdown', async ({ page }) => {
+      const wrapper = example(page, 'required-tree-select');
+      await open(wrapper);
+
+      await expect(page.getByRole('treeitem').first()).toBeVisible();
+      await page.keyboard.press('Escape');
+      await expect(page.getByRole('treeitem')).toHaveCount(0);
+    });
+  });
+
+  test.describe('Real directory expand/collapse via click', () => {
+    test('clicking a directory row toggles its real aria-expanded state and reveals its children', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'required-tree-select');
+      await open(wrapper);
+
+      const directory = page.getByRole('treeitem', { name: 'Dataset 1' });
+      await expect(directory).toHaveAttribute('aria-expanded', 'false');
+
+      await directory.click();
+
+      await expect(directory).toHaveAttribute('aria-expanded', 'true');
+      await expect(
+        page.getByRole('treeitem', { name: 'Attr1_1' })
+      ).toBeVisible();
+    });
+  });
+
+  test.describe('Real Enter/Space on a leaf node', () => {
+    test('Enter selects a leaf node and closes the dropdown despite the keydown handler calling preventDefault', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'required-tree-select');
+      await open(wrapper);
+
+      const leaf = page.getByRole('treeitem', { name: 'Attr2_2' });
+      await leaf.focus();
+      await page.keyboard.press('Enter');
+
+      await expect(
+        wrapper.getByTestId('cps-treeselect-selected-value')
+      ).toHaveText('Attr2_2');
+      await expect(page.getByRole('treeitem')).toHaveCount(0);
+    });
+
+    test('Space selects a leaf node and closes the dropdown', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'required-tree-select');
+      await open(wrapper);
+
+      const leaf = page.getByRole('treeitem', { name: 'Attr3_2' });
+      await leaf.focus();
+      await page.keyboard.press('Space');
+
+      await expect(
+        wrapper.getByTestId('cps-treeselect-selected-value')
+      ).toHaveText('Attr3_2');
+      await expect(page.getByRole('treeitem')).toHaveCount(0);
+    });
+  });
+
+  test.describe('Real Enter on a directory node', () => {
+    test('expands the directory instead of selecting/closing', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'required-tree-select');
+      await open(wrapper);
+
+      const directory = page.getByRole('treeitem', { name: 'Dataset 3' });
+      await directory.focus();
+      await expect(directory).toHaveAttribute('aria-expanded', 'false');
+
+      await page.keyboard.press('Enter');
+
+      await expect(directory).toHaveAttribute('aria-expanded', 'true');
+      await expect(page.getByRole('treeitem')).not.toHaveCount(0);
+    });
+  });
+
+  test.describe('Real virtual scroll rendering', () => {
+    test('a virtualized tree renders real treeitem nodes on open', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'virtual-scroll-tree-select');
+      await open(wrapper);
+
+      await expect(page.getByRole('treeitem').first()).toBeVisible();
+    });
+  });
+
+  test.describe('Real chip removal', () => {
+    test('clicking a chip close button removes it from the real selection', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'virtual-scroll-tree-select');
+      const chips = wrapper
+        .getByTestId('cps-treeselect-chips-group')
+        .locator('cps-chip');
+      await expect(chips.first()).toBeVisible();
+      const initialCount = await chips.count();
+      expect(initialCount).toBeGreaterThan(0);
+
+      await chips.first().getByRole('button').click();
+
+      await expect(chips).toHaveCount(initialCount - 1);
+    });
+  });
+
+  test.describe('Real prefix icon', () => {
+    test('the configured prefix icon renders in the real box', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'prefix-icon-tree-select');
+
+      await expect(
+        wrapper.getByTestId('cps-treeselect-prefix-icon')
+      ).toBeVisible();
+    });
+  });
+
+  test.describe('Real required-field validation', () => {
+    test('clearing the value and blurring shows a real required-field error', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'required-tree-select');
+      const container = wrapper.getByTestId('cps-treeselect-container');
+
+      await wrapper.getByTestId('cps-treeselect-clear-icon').click();
+      await container.focus();
+      await page.keyboard.press('Tab');
+
+      const error = wrapper.getByTestId('cps-treeselect-error');
+      await expect(error).toHaveText('Field is required');
+      const describedBy = await container.getAttribute('aria-describedby');
+      expect(describedBy).toBeTruthy();
+      await expect(error).toHaveAttribute('id', describedBy!);
+    });
+  });
+
+  test.describe('Real two-way binding - real readout', () => {
+    test('selecting a node updates the visible bound value', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'two-way-binding-tree-select');
+      const readout = page.getByTestId('two-way-binding-tree-select-value');
+
+      await open(wrapper);
+      await page.getByRole('treeitem', { name: 'Attr3_2' }).click();
+
+      await expect(readout).toHaveText('Attr3_2');
+    });
+  });
+
+  test.describe('Real accessible-name computation', () => {
+    test('an unlabeled tree select exposes its ariaLabel as the real accessible name', async ({
+      page
+    }) => {
+      await expect(
+        page.getByRole('combobox', { name: 'Select an item', exact: true })
+      ).toBeVisible();
+    });
+  });
+
+  test.describe('hideDetails suppresses the hint/error row entirely', () => {
+    test('no hint element is rendered when hideDetails is set', async ({
+      page
+    }) => {
+      const hint = example(page, 'hide-details-tree-select').getByTestId(
+        'cps-treeselect-hint'
+      );
+
+      await expect(hint).toHaveCount(0);
+    });
+  });
+
+  test.describe('Real expandAll()/collapseAll()', () => {
+    test('Expand All reveals a two-level-deep node without any manual clicks', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'expand-collapse-tree-select');
+
+      await page.getByTestId('expand-all-tree-select-btn').click();
+      await open(wrapper);
+
+      await expect(
+        page.getByRole('treeitem', { name: 'Dataset 1' })
+      ).toHaveAttribute('aria-expanded', 'true');
+      await expect(
+        page.getByRole('treeitem', { name: 'Attr1_1' })
+      ).toHaveAttribute('aria-expanded', 'true');
+      await expect(page.getByRole('treeitem', { name: 'AttrA' })).toBeVisible();
+    });
+
+    test('Collapse All hides a previously-expanded node', async ({ page }) => {
+      const wrapper = example(page, 'expand-collapse-tree-select');
+
+      await open(wrapper);
+      await page.getByRole('treeitem', { name: 'Dataset 1' }).click();
+      await expect(
+        page.getByRole('treeitem', { name: 'Attr1_1' })
+      ).toBeVisible();
+      await page.keyboard.press('Escape');
+
+      await page.getByTestId('collapse-all-tree-select-btn').click();
+      await open(wrapper);
+
+      await expect(
+        page.getByRole('treeitem', { name: 'Dataset 1' })
+      ).toHaveAttribute('aria-expanded', 'false');
+      await expect(page.getByRole('treeitem', { name: 'Attr1_1' })).toHaveCount(
+        0
+      );
+    });
+  });
+
+  test.describe('openOnClear=false', () => {
+    test('clearing a pre-filled tree select does not reopen the dropdown', async ({
+      page
+    }) => {
+      const wrapper = example(page, 'open-on-clear-false-tree-select');
+
+      await wrapper.getByTestId('cps-treeselect-clear-icon').click();
+
+      await expect(page.getByRole('treeitem')).toHaveCount(0);
+      await expect(
+        wrapper.getByTestId('cps-treeselect-placeholder')
+      ).toBeVisible();
+    });
+  });
+});
diff --git a/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.html b/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.html
index 6e8dae9b9..7cda7b043 100644
--- a/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.html
+++ b/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.html
@@ -6,6 +6,7 @@
     [tsCode]="examples.requiredTreeSelect.ts">
     <form [formGroup]="form">
       <cps-tree-select
+        data-testid="required-tree-select"
         label="Required single tree select with a tooltip"
         [options]="options"
         optionLabel="label"
@@ -18,11 +19,38 @@
     </form>
   </app-code-example>
 
+  <app-code-example
+    label="Tree select with expand/collapse all controls"
+    [htmlCode]="examples.expandCollapseTreeSelect.html"
+    [tsCode]="examples.expandCollapseTreeSelect.ts">
+    <cps-tree-select
+      #expandCollapseTreeSelectRef
+      data-testid="expand-collapse-tree-select"
+      label="Tree select with expand/collapse all controls"
+      [options]="options"
+      optionLabel="label"
+      optionInfo="attrType"
+      placeholder="Select element"
+      [clearable]="true">
+    </cps-tree-select>
+    <div class="tree-select-actions">
+      <cps-button
+        data-testid="expand-all-tree-select-btn"
+        label="Expand All"
+        (clicked)="expandCollapseTreeSelectRef.expandAll()"></cps-button>
+      <cps-button
+        data-testid="collapse-all-tree-select-btn"
+        label="Collapse All"
+        (clicked)="expandCollapseTreeSelectRef.collapseAll()"></cps-button>
+    </div>
+  </app-code-example>
+
   <app-code-example
     label="Loading tree select"
     [htmlCode]="examples.loadingTreeSelect.html"
     [tsCode]="examples.loadingTreeSelect.ts">
     <cps-tree-select
+      data-testid="loading-tree-select"
       label="Loading tree select"
       [loading]="true"
       [options]="options"
@@ -35,6 +63,7 @@
     label="Disabled tree select"
     [htmlCode]="examples.disabledTreeSelect.html">
     <cps-tree-select
+      data-testid="disabled-tree-select"
       label="Disabled tree select"
       [disabled]="true"
       hint="This tree select is disabled">
@@ -46,6 +75,7 @@
     [htmlCode]="examples.multipleTreeSelect.html"
     [tsCode]="examples.multipleTreeSelect.ts">
     <cps-tree-select
+      data-testid="multiple-tree-select"
       label="Multiple tree select"
       [options]="options"
       optionLabel="label"
@@ -63,6 +93,7 @@
     [htmlCode]="examples.virtualScrollTreeSelect.html"
     [tsCode]="examples.virtualScrollTreeSelect.ts">
     <cps-tree-select
+      data-testid="virtual-scroll-tree-select"
       label="Multiple tree select with virtual scroll, chips and persistent clear icon"
       [options]="options"
       optionLabel="label"
@@ -81,6 +112,7 @@
     [htmlCode]="examples.nonClosableChipsTreeSelect.html"
     [tsCode]="examples.nonClosableChipsTreeSelect.ts">
     <cps-tree-select
+      data-testid="non-closable-chips-tree-select"
       label="Multiple tree select with non-closable chips"
       [options]="options"
       optionInfo="attrType"
@@ -97,6 +129,7 @@
     [htmlCode]="examples.prefixIconTreeSelect.html"
     [tsCode]="examples.prefixIconTreeSelect.ts">
     <cps-tree-select
+      data-testid="prefix-icon-tree-select"
       label="Multiple tree select with prefix icon"
       [options]="options"
       optionInfo="attrType"
@@ -114,6 +147,7 @@
     [tsCode]="examples.twoWayBindingTreeSelect.ts">
     <div class="sync-val-example">
       <cps-tree-select
+        data-testid="two-way-binding-tree-select"
         [initialExpandDirectories]="true"
         width="31.25rem"
         label="Single tree select with two-way binding, select something"
@@ -125,7 +159,9 @@
         [(ngModel)]="syncVal"
         [ngModelOptions]="{ standalone: true }">
       </cps-tree-select>
-      <span class="sync-val">{{ syncVal?.label }}</span>
+      <span class="sync-val" data-testid="two-way-binding-tree-select-value">{{
+        syncVal?.label
+      }}</span>
     </div>
   </app-code-example>
 
@@ -134,6 +170,7 @@
     [htmlCode]="examples.underlinedTreeSelect.html"
     [tsCode]="examples.underlinedTreeSelect.ts">
     <cps-tree-select
+      data-testid="underlined-tree-select"
       label="Underlined tree select"
       appearance="underlined"
       [options]="options"
@@ -149,6 +186,7 @@
     [htmlCode]="examples.borderlessTreeSelect.html"
     [tsCode]="examples.borderlessTreeSelect.ts">
     <cps-tree-select
+      data-testid="borderless-tree-select"
       label="Borderless tree select"
       appearance="borderless"
       [options]="options"
@@ -158,4 +196,40 @@
       [chips]="false">
     </cps-tree-select>
   </app-code-example>
+
+  <app-code-example
+    label="Unlabeled tree select with an accessible name"
+    [htmlCode]="examples.ariaLabelTreeSelect.html">
+    <cps-tree-select
+      data-testid="aria-label-tree-select"
+      ariaLabel="Select an item"
+      [options]="options">
+    </cps-tree-select>
+  </app-code-example>
+
+  <app-code-example
+    label="Tree select with hidden hint/error details"
+    [htmlCode]="examples.hideDetailsTreeSelect.html">
+    <cps-tree-select
+      data-testid="hide-details-tree-select"
+      label="Tree select with hidden hint/error details"
+      hint="You should not see this hint"
+      [options]="options"
+      [hideDetails]="true">
+    </cps-tree-select>
+  </app-code-example>
+
+  <app-code-example
+    label="Tree select with openOnClear disabled"
+    [htmlCode]="examples.openOnClearFalseTreeSelect.html">
+    <cps-tree-select
+      data-testid="open-on-clear-false-tree-select"
+      label="Tree select with openOnClear disabled"
+      hint="Clearing this tree select will not reopen the dropdown"
+      [options]="options"
+      [value]="options[1].children[0]"
+      [clearable]="true"
+      [openOnClear]="false">
+    </cps-tree-select>
+  </app-code-example>
 </app-component-docs-viewer>
diff --git a/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.scss b/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.scss
index fe6f52680..cdd5b7d00 100644
--- a/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.scss
+++ b/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.scss
@@ -5,3 +5,9 @@
     margin-left: 1.5rem;
   }
 }
+
+.tree-select-actions {
+  display: flex;
+  gap: 0.75rem;
+  margin-top: 0.75rem;
+}
diff --git a/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.ts b/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.ts
index 89953b611..32bf097e2 100644
--- a/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.ts
+++ b/projects/composition/src/app/pages/tree-select-page/tree-select-page.component.ts
@@ -6,7 +6,7 @@ import {
   UntypedFormGroup,
   Validators
 } from '@angular/forms';
-import { CpsTreeSelectComponent } from 'cps-ui-kit';
+import { CpsButtonComponent, CpsTreeSelectComponent } from 'cps-ui-kit';
 import ComponentData from '../../api-data/cps-tree-select.json';
 import { ComponentDocsViewerComponent } from '../../components/component-docs-viewer/component-docs-viewer.component';
 import { CodeExampleComponent } from '../../components/code-example/code-example.component';
@@ -15,6 +15,7 @@ import { treeSelectExamples } from './tree-select-page.examples';
 @Component({
   imports: [
     CpsTreeSelectComponent,
+    CpsButtonComponent,
     FormsModule,
     ReactiveFormsModule,
     ComponentDocsViewerComponent,
diff --git a/projects/composition/src/app/pages/tree-select-page/tree-select-page.examples.ts b/projects/composition/src/app/pages/tree-select-page/tree-select-page.examples.ts
index 53950476c..a9381c77e 100644
--- a/projects/composition/src/app/pages/tree-select-page/tree-select-page.examples.ts
+++ b/projects/composition/src/app/pages/tree-select-page/tree-select-page.examples.ts
@@ -116,6 +116,26 @@ ngOnInit(): void {
 }`
     },
 
+    expandCollapseTreeSelect: {
+      html: `
+<cps-tree-select
+  #expandCollapseTreeSelectRef
+  label="Tree select with expand/collapse all controls"
+  [options]="options"
+  optionLabel="label"
+  optionInfo="attrType"
+  placeholder="Select element"
+  [clearable]="true">
+</cps-tree-select>
+<cps-button
+  label="Expand All"
+  (clicked)="expandCollapseTreeSelectRef.expandAll()"></cps-button>
+<cps-button
+  label="Collapse All"
+  (clicked)="expandCollapseTreeSelectRef.collapseAll()"></cps-button>`,
+      ts: treeOptionsTs
+    },
+
     loadingTreeSelect: {
       html: `
 <cps-tree-select
@@ -256,6 +276,39 @@ syncVal: any = null;`
   [clearable]="true"
   [multiple]="true"
   [chips]="false">
+</cps-tree-select>`,
+      ts: treeOptionsTs
+    },
+
+    ariaLabelTreeSelect: {
+      html: `
+<cps-tree-select
+  ariaLabel="Select an item"
+  [options]="options">
+</cps-tree-select>`,
+      ts: treeOptionsTs
+    },
+
+    hideDetailsTreeSelect: {
+      html: `
+<cps-tree-select
+  label="Tree select with hidden hint/error details"
+  hint="You should not see this hint"
+  [options]="options"
+  [hideDetails]="true">
+</cps-tree-select>`,
+      ts: treeOptionsTs
+    },
+
+    openOnClearFalseTreeSelect: {
+      html: `
+<cps-tree-select
+  label="Tree select with openOnClear disabled"
+  hint="Clearing this tree select will not reopen the dropdown"
+  [options]="options"
+  [value]="options[1].children[0]"
+  [clearable]="true"
+  [openOnClear]="false">
 </cps-tree-select>`,
       ts: treeOptionsTs
     }
diff --git a/projects/cps-ui-kit/src/lib/components/cps-tree-select/cps-tree-select.component.html b/projects/cps-ui-kit/src/lib/components/cps-tree-select/cps-tree-select.component.html
index 27fa1d807..0afe3bf58 100644
--- a/projects/cps-ui-kit/src/lib/components/cps-tree-select/cps-tree-select.component.html
+++ b/projects/cps-ui-kit/src/lib/components/cps-tree-select/cps-tree-select.component.html
@@ -1,14 +1,16 @@
 <div
   [style.width]="cvtWidth"
   class="cps-treeselect"
+  data-testid="cps-treeselect"
   [class.disabled]="disabled"
   [class.error]="error">
   @if (label) {
-    <div class="cps-treeselect-label">
-      <label>{{ label }}</label>
+    <div class="cps-treeselect-label" data-testid="cps-treeselect-label">
+      <label data-testid="cps-treeselect-label-text">{{ label }}</label>
       @if (infoTooltip) {
         <cps-info-circle
           class="cps-treeselect-label-info-circle"
+          data-testid="cps-treeselect-info-circle"
           size="xsmall"
           [tooltipPosition]="infoTooltipPosition"
           [tooltipContentClass]="infoTooltipClass"
@@ -21,6 +23,7 @@
   }
   <div
     class="cps-treeselect-container"
+    data-testid="cps-treeselect-container"
     [tabindex]="disabled ? -1 : 0"
     [class.focused]="isOpened"
     [class.persistent-clear]="persistentClear"
@@ -41,13 +44,18 @@
     (keydown)="onKeyDown($event)"
     (focus)="onFocus()"
     (blur)="onBlur()">
-    <div class="cps-treeselect-box" #boxEl (click)="onBoxClick()">
+    <div
+      class="cps-treeselect-box"
+      data-testid="cps-treeselect-box"
+      #boxEl
+      (click)="onBoxClick()">
       <div class="cps-treeselect-box-left">
         @if (prefixIcon) {
           <cps-icon
             [icon]="prefixIcon"
             [style.color]="disabled ? '#9a9595' : null"
             [size]="prefixIconSize"
+            data-testid="cps-treeselect-prefix-icon"
             class="prefix-icon">
           </cps-icon>
         }
@@ -55,7 +63,9 @@
           (!treeSelection && !multiple) ||
           (treeSelection?.length < 1 && multiple)
         ) {
-          <div class="cps-treeselect-box-placeholder">
+          <div
+            class="cps-treeselect-box-placeholder"
+            data-testid="cps-treeselect-placeholder">
             {{ placeholder }}
           </div>
         }
@@ -65,11 +75,22 @@
         ) {
           <div class="cps-treeselect-box-items">
             @if (!multiple) {
-              <span class="single-item"> {{ treeSelection.label }}</span>
+              <span
+                class="single-item"
+                data-testid="cps-treeselect-selected-value">
+                {{ treeSelection.label }}</span
+              >
             }
             @if (multiple && !chips) {
-              <div class="text-group" role="list" aria-label="Selected options">
-                <span class="text-group-item" role="listitem">
+              <div
+                class="text-group"
+                data-testid="cps-treeselect-text-group"
+                role="list"
+                aria-label="Selected options">
+                <span
+                  class="text-group-item"
+                  data-testid="cps-treeselect-selected-text-item"
+                  role="listitem">
                   {{
                     treeSelection
                       | combineLabels: innerOptions : '' : 'label' : true
@@ -80,6 +101,7 @@
             @if (multiple && chips) {
               <div
                 class="chips-group"
+                data-testid="cps-treeselect-chips-group"
                 role="list"
                 aria-label="Selected options">
                 @for (val of treeSelection; track val) {
@@ -101,6 +123,7 @@
         @if (clearable && !disabled) {
           <span
             role="button"
+            data-testid="cps-treeselect-clear-icon"
             aria-label="Clear selection"
             [tabindex]="disabled ? -1 : 0"
             (click)="clear($event)"
@@ -122,6 +145,7 @@
         @if (showChevron) {
           <span
             class="cps-treeselect-box-chevron"
+            data-testid="cps-treeselect-chevron"
             role="button"
             [attr.aria-label]="isOpened ? 'Collapse options' : 'Expand options'"
             [tabindex]="disabled ? -1 : 0"
@@ -147,6 +171,7 @@
       <div
         [id]="optionsTreeId"
         class="cps-treeselect-options"
+        data-testid="cps-treeselect-options"
         [class.arrow-navigating]="isArrowNavigating"
         [style.width.px]="boxWidthPx"
         (keydown)="onOptionsKeyDown($event)">
@@ -167,22 +192,35 @@
           [metaKeySelection]="multiple ? false : true"
           [selectionMode]="multiple ? 'multiple' : 'single'">
           <ng-template let-node pTemplate="directory">
-            <span class="cps-treeselect-directory-elem">{{ node.label }}</span>
+            <span
+              class="cps-treeselect-directory-elem"
+              [attr.data-testid]="'cps-treeselect-directory-elem-' + node.key"
+              >{{ node.label }}</span
+            >
           </ng-template>
           <ng-template let-node pTemplate="default">
-            <span class="cps-treeselect-option">
+            <span
+              class="cps-treeselect-option"
+              [attr.data-testid]="'cps-treeselect-option-' + node.key">
               <span class="cps-treeselect-option-left">
                 @if (multiple) {
-                  <span class="cps-treeselect-option-check"> </span>
+                  <span
+                    class="cps-treeselect-option-check"
+                    [attr.data-testid]="
+                      'cps-treeselect-option-check-' + node.key
+                    ">
+                  </span>
                 }
                 <span
                   class="cps-treeselect-option-label"
+                  [attr.data-testid]="'cps-treeselect-option-label-' + node.key"
                   [class.virtual-row]="virtualScroll"
                   >{{ node.label }}</span
                 >
               </span>
               <span
                 class="cps-treeselect-option-info"
+                [attr.data-testid]="'cps-treeselect-option-info-' + node.key"
                 [class.virtual-row]="virtualScroll"
                 >{{ node.info }}</span
               >
@@ -197,12 +235,16 @@
         radius="0.25rem"
         opacity="0.3"
         class="cps-treeselect-progress-bar"
+        data-testid="cps-treeselect-loading-bar"
         bgColor="transparent">
       </cps-progress-linear>
     }
   </div>
   @if (!error && !hideDetails) {
-    <div [id]="hintId" class="cps-treeselect-hint">
+    <div
+      [id]="hintId"
+      class="cps-treeselect-hint"
+      data-testid="cps-treeselect-hint">
       {{ hint }}
     </div>
   }
@@ -210,6 +252,7 @@
     <div
       [id]="errorId"
       class="cps-treeselect-error"
+      data-testid="cps-treeselect-error"
       aria-live="polite"
       aria-atomic="true">
       {{ error }}
diff --git a/projects/cps-ui-kit/src/lib/components/internal/cps-base-tree-dropdown/cps-base-tree-dropdown.component.ts b/projects/cps-ui-kit/src/lib/components/internal/cps-base-tree-dropdown/cps-base-tree-dropdown.component.ts
index a562f1994..e26992b17 100644
--- a/projects/cps-ui-kit/src/lib/components/internal/cps-base-tree-dropdown/cps-base-tree-dropdown.component.ts
+++ b/projects/cps-ui-kit/src/lib/components/internal/cps-base-tree-dropdown/cps-base-tree-dropdown.component.ts
@@ -408,12 +408,16 @@ export class CpsBaseTreeDropdownComponent
     this.optionsMap?.forEach((value) => {
       if (value.children) value.expanded = true;
     });
+    this._treeRefreshKey++;
+    this.treeList?.cd?.markForCheck();
   }
 
   collapseAll() {
     this.optionsMap?.forEach((value) => {
       if (value.children) value.expanded = false;
     });
+    this._treeRefreshKey++;
+    this.treeList?.cd?.markForCheck();
   }
 
   // eslint-disable-next-line @typescript-eslint/no-empty-function