fix(textarea): canGrow limit when maxRows (#DS-5158)

packages/components/textarea/e2e.playwright-spec.ts

@@ -1,7 +1,25 @@
 import { expect, Locator, Page, test } from '@playwright/test';
 import { e2eEnableDarkTheme } from '../../e2e/utils';
 
+const getHeight = async (locator: Locator): Promise<number> => {
+    await expect(locator).toBeVisible();
+    const box = await locator.boundingBox();
+
+    expect(box).not.toBeNull();
+
+    return box!.height;
+};
+
+const pasteFromClipboard = async (page: Page, textarea: Locator, text: string) => {
+    await page.evaluate((t) => navigator.clipboard.writeText(t), text);
+    await textarea.click();
+    await page.keyboard.press('ControlOrMeta+a');
+    await page.keyboard.press('ControlOrMeta+v');
+};
+
 test.describe('KbqTextareaModule', () => {
+    test.use({ permissions: ['clipboard-read', 'clipboard-write'] });
+
     test.describe('E2eTextareaStates', () => {
         const getComponent = (page: Page): Locator => page.getByTestId('e2eTextareaStates');
 
@@ -16,18 +34,6 @@ test.describe('KbqTextareaModule', () => {
     test.describe('E2eTextareaGrowBehavior', () => {
         const getTextarea = (page: Page): Locator => page.getByTestId('grow_textarea');
 
-        // Wait for the locator to be visible, then resolve its rendered height.
-        // Auto-retries via `toBeVisible` and asserts the bounding box is non-null
-        // so a transient detach surfaces as a readable expect failure, not a TypeError.
-        const getHeight = async (locator: Locator): Promise<number> => {
-            await expect(locator).toBeVisible();
-            const box = await locator.boundingBox();
-
-            expect(box).not.toBeNull();
-
-            return box!.height;
-        };
-
         test('should grow initially when ngModel has multiple lines', async ({ page }) => {
             await page.goto('/E2eTextareaGrowBehavior');
 
@@ -38,10 +44,10 @@ test.describe('KbqTextareaModule', () => {
             await page.goto('/E2eTextareaGrowBehavior');
             const textarea = getTextarea(page);
 
-            await page.getByTestId('grow_set_short').click();
+            await pasteFromClipboard(page, textarea, 'test\ntest');
             const shortHeight = await getHeight(textarea);
 
-            await page.getByTestId('grow_set_long').click();
+            await pasteFromClipboard(page, textarea, 'test\ntest\ntest\ntest\ntest\ntest');
             const longHeight = await getHeight(textarea);
 
             expect(longHeight).toBeGreaterThan(shortHeight);
@@ -51,16 +57,54 @@ test.describe('KbqTextareaModule', () => {
             await page.goto('/E2eTextareaGrowBehavior');
             const textarea = getTextarea(page);
 
-            await page.getByTestId('grow_set_long').click();
+            await pasteFromClipboard(page, textarea, 'test\ntest\ntest\ntest\ntest\ntest');
             const longHeight = await getHeight(textarea);
 
-            await page.getByTestId('grow_set_short').click();
+            await pasteFromClipboard(page, textarea, 'test\ntest');
             const shortHeight = await getHeight(textarea);
 
             expect(shortHeight).toBeLessThan(longHeight);
         });
     });
 
+    test.describe('E2eTextareaGrowMaxRows', () => {
+        const getTextarea = (page: Page): Locator => page.getByTestId('grow-max-rows_textarea');
+
+        test('should grow initially when ngModel has multiple lines', async ({ page }) => {
+            await page.goto('/E2eTextareaGrowMaxRows');
+
+            expect(await getHeight(getTextarea(page))).toBeGreaterThan(50);
+        });
+
+        test('should grow to maxRows height when pasting text exceeding maxRows', async ({ page }) => {
+            await page.goto('/E2eTextareaGrowMaxRows');
+            const textarea = getTextarea(page);
+            const shortHeight = await getHeight(textarea);
+
+            await pasteFromClipboard(
+                page,
+                textarea,
+                'line1\nline2\nline3\nline4\nline5\nline6\nline7\nline8\nline9\nline10'
+            );
+            expect(await getHeight(textarea)).toBeGreaterThan(shortHeight);
+        });
+
+        test('should not grow beyond maxRows height', async ({ page }) => {
+            await page.goto('/E2eTextareaGrowMaxRows');
+            const textarea = getTextarea(page);
+
+            await pasteFromClipboard(page, textarea, 'line1\nline2\nline3\nline4\nline5');
+            const atMaxRowsHeight = await getHeight(textarea);
+
+            await pasteFromClipboard(
+                page,
+                textarea,
+                'line1\nline2\nline3\nline4\nline5\nline6\nline7\nline8\nline9\nline10'
+            );
+            expect(await getHeight(textarea)).toBe(atMaxRowsHeight);
+        });
+    });
+
     test.describe('E2eTextareaScrollOnFocus', () => {
         test('should not scroll the page when focusing a kbqTextarea', async ({ page }) => {
             await page.goto('/E2eTextareaScrollOnFocus');

packages/components/textarea/e2e.ts

@@ -101,10 +101,6 @@ export class E2eTextareaStates {
         <kbq-form-field>
             <textarea kbqTextarea data-testid="grow_textarea" [(ngModel)]="value"></textarea>
         </kbq-form-field>
-
-        <button data-testid="grow_set_short" type="button" (click)="value.set(short)">Short</button>
-        <button data-testid="grow_set_medium" type="button" (click)="value.set(medium)">Medium</button>
-        <button data-testid="grow_set_long" type="button" (click)="value.set(long)">Long</button>
     `,
     styles: `
         :host {
@@ -121,11 +117,39 @@ export class E2eTextareaStates {
     }
 })
 export class E2eTextareaGrowBehavior {
-    protected readonly short = 'test\ntest';
-    protected readonly medium = 'test\ntest\ntest';
-    protected readonly long = 'test\ntest\ntest\ntest\ntest\ntest';
+    protected readonly value = model('test\ntest\ntest');
+}
 
-    protected readonly value = model<string>(this.medium);
+@Component({
+    selector: 'e2e-textarea-grow-max-rows',
+    imports: [KbqTextareaModule, FormsModule],
+    template: `
+        <kbq-form-field>
+            <textarea
+                kbqTextarea
+                data-testid="grow-max-rows_textarea"
+                [canGrow]="true"
+                [maxRows]="5"
+                [(ngModel)]="value"
+            ></textarea>
+        </kbq-form-field>
+    `,
+    styles: `
+        :host {
+            display: flex;
+            flex-direction: column;
+            gap: var(--kbq-size-s);
+            padding: var(--kbq-size-s);
+            width: 320px;
+        }
+    `,
+    changeDetection: ChangeDetectionStrategy.OnPush,
+    host: {
+        'data-testid': 'e2eTextareaGrowMaxRows'
+    }
+})
+export class E2eTextareaGrowMaxRows {
+    protected readonly value = model('line1\nline2\nline3');
 }
 
 const longTextareaContent =

packages/components/textarea/textarea.component.spec.ts

@@ -1,5 +1,13 @@
 import { Component, Provider, Type, viewChild } from '@angular/core';
-import { ComponentFixture, ComponentFixtureAutoDetect, TestBed, fakeAsync, flush, tick } from '@angular/core/testing';
+import {
+    ComponentFixture,
+    ComponentFixtureAutoDetect,
+    TestBed,
+    fakeAsync,
+    flush,
+    flushMicrotasks,
+    tick
+} from '@angular/core/testing';
 import {
     AsyncValidatorFn,
     FormControl,
@@ -141,6 +149,19 @@ class TextareaControlWithAsyncValidators {
     });
 }
 
+@Component({
+    imports: [KbqTextareaModule, FormsModule],
+    template: `
+        <kbq-form-field>
+            <textarea kbqTextarea [canGrow]="true" [maxRows]="3" [(ngModel)]="value"></textarea>
+        </kbq-form-field>
+    `
+})
+class KbqTextareaGrowWithMaxRows {
+    readonly textarea = viewChild.required(KbqTextarea);
+    value: string = 'line1\nline2';
+}
+
 @Component({
     imports: [KbqTextareaModule, ReactiveFormsModule],
     template: `
@@ -279,6 +300,73 @@ describe('KbqTextarea', () => {
 
             expect(getTextareaElement(fixture).classList.contains('kbq-textarea-resizable')).toBe(false);
         });
+
+        it('should not have kbq-textarea_max-row-limit-reached class when maxRows is not exceeded', () => {
+            const fixture = createComponent(KbqTextareaGrowWithMaxRows);
+
+            fixture.detectChanges();
+
+            expect(getTextareaElement(fixture).classList.contains('kbq-textarea_max-row-limit-reached')).toBe(false);
+        });
+    });
+
+    describe('grow behavior', () => {
+        it('should call stateChanges.next when input event fires with a changed value', fakeAsync(() => {
+            const fixture = createComponent(KbqTextareaForBehaviors);
+
+            fixture.detectChanges();
+            tick();
+
+            const textareaEl = getTextareaElement(fixture);
+            const textarea = fixture.debugElement.query(By.directive(KbqTextarea)).injector.get(KbqTextarea);
+            const spy = jest.spyOn(textarea.stateChanges, 'next');
+
+            textareaEl.value = 'changed value';
+            dispatchFakeEvent(textareaEl, 'input');
+
+            expect(spy).toHaveBeenCalled();
+        }));
+
+        it('should emit stateChanges once per input change: dirtyCheckNativeValue in (input) prevents ngDoCheck from re-emitting', fakeAsync(() => {
+            const fixture = createComponent(KbqTextareaForBehaviors);
+
+            fixture.detectChanges();
+            tick(); // flush initial setTimeout(grow, 0) from ngOnInit
+
+            const textareaEl = getTextareaElement(fixture);
+            const textareaDir = fixture.debugElement.query(By.directive(KbqTextarea)).injector.get(KbqTextarea);
+            const nextSpy = jest.spyOn(textareaDir.stateChanges, 'next');
+
+            textareaEl.value = 'test\ntest\ntest\ntest\ntest';
+            // (input) → dirtyCheckNativeValue() → previousNativeValue updated → stateChanges.next() [#1]
+            // Zone.js auto-CD → ngDoCheck → dirtyCheckNativeValue: previousNativeValue === value → no emit
+            dispatchFakeEvent(textareaEl, 'input');
+            fixture.detectChanges(); // explicit CD: no further changes
+
+            expect(nextSpy).toHaveBeenCalledTimes(1);
+        }));
+
+        it('should defer grow to microtask so lineHeight is initialized before first grow call', fakeAsync(() => {
+            const fixture = createComponent(KbqTextareaGrowWithMaxRows);
+
+            const textareaDir = fixture.debugElement.query(By.directive(KbqTextarea)).injector.get(KbqTextarea);
+
+            fixture.detectChanges(); // ngOnInit queues M1 (lineHeight init); stateChanges may emit → grow microtasks pending
+            flushMicrotasks(); // drain M1 + any grow microtasks queued during detectChanges
+            tick(); // flush setTimeout(grow, 0) from ngOnInit
+
+            // Spy set up AFTER initial flushes — only captures subsequent grow() calls
+            const growSpy = jest.spyOn(textareaDir, 'grow');
+
+            // observeOn(asapScheduler) defers grow to microtask (M2), NOT synchronous
+            textareaDir.stateChanges.next();
+
+            expect(growSpy).not.toHaveBeenCalled(); // M2 still pending
+
+            flushMicrotasks(); // M2 runs → grow()
+
+            expect(growSpy).toHaveBeenCalledTimes(1);
+        }));
     });
 
     describe('ErrorStateMatcher', () => {

packages/components/textarea/textarea.component.ts

@@ -1,4 +1,4 @@
-import { coerceBooleanProperty } from '@angular/cdk/coercion';
+import { coerceBooleanProperty, coerceCssPixelValue } from '@angular/cdk/coercion';
 import { Platform } from '@angular/cdk/platform';
 import {
     booleanAttribute,
@@ -16,6 +16,7 @@ import {
     OnInit,
     Renderer2
 } from '@angular/core';
+import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
 import { FormGroupDirective, NgControl, NgForm, UntypedFormControl } from '@angular/forms';
 import {
     CanUpdateErrorState,
@@ -24,8 +25,7 @@ import {
     KBQ_WINDOW
 } from '@koobiq/components/core';
 import { KbqFormFieldControl } from '@koobiq/components/form-field';
-import { Subject, Subscription } from 'rxjs';
-import { delay } from 'rxjs/operators';
+import { asapScheduler, observeOn, Subject } from 'rxjs';
 
 export const KBQ_TEXTAREA_VALUE_ACCESSOR = new InjectionToken<{ value: any }>('KBQ_TEXTAREA_VALUE_ACCESSOR');
 
@@ -45,7 +45,7 @@ let nextUniqueId = 0;
         '[required]': 'required',
         '(blur)': 'onBlur()',
         '(focus)': 'focusChanged(true)',
-        '(paste)': 'stateChanges.next()'
+        '(input)': 'dirtyCheckNativeValue()'
     },
     exportAs: 'kbqTextarea'
 })
@@ -208,7 +208,6 @@ export class KbqTextarea
     private _required = false;
 
     private valueAccessor: { value: any };
-    private growSubscription: Subscription;
 
     private lineHeight: number = 0;
     private minHeight: number = 0;
@@ -229,7 +228,7 @@ export class KbqTextarea
         // eslint-disable-next-line @angular-eslint/no-lifecycle-call
         this.parent?.animationDone.subscribe(() => this.ngOnInit());
 
-        this.growSubscription = this.stateChanges.pipe(delay(0)).subscribe(this.grow);
+        this.stateChanges.pipe(observeOn(asapScheduler), takeUntilDestroyed()).subscribe(() => this.grow());
     }
 
     ngOnInit() {
@@ -257,7 +256,6 @@ export class KbqTextarea
 
     ngOnDestroy() {
         this.stateChanges.complete();
-        this.growSubscription.unsubscribe();
     }
 
     ngDoCheck() {
@@ -313,12 +311,9 @@ export class KbqTextarea
 
             this.rowsCount = Math.floor(height / this.lineHeight);
 
-            if (!this.maxRowLimitReached) {
-                textarea.style.minHeight = `${height}px`;
-            } else if (!textarea.style.minHeight && this.lineHeight) {
-                // need for first initialization when value above maxRows
-                textarea.style.minHeight = `${this.maxRows() * this.lineHeight}px`;
-            }
+            textarea.style.minHeight = coerceCssPixelValue(
+                this.maxRowLimitReached ? this.maxRows() * this.lineHeight : height
+            );
         });
     };
 

packages/e2e/routes.ts

@@ -82,7 +82,12 @@ import {
     E2eTagListStates,
     E2eTagStateAndStyle
 } from '../components/tags/e2e';
-import { E2eTextareaGrowBehavior, E2eTextareaScrollOnFocus, E2eTextareaStates } from '../components/textarea/e2e';
+import {
+    E2eTextareaGrowBehavior,
+    E2eTextareaGrowMaxRows,
+    E2eTextareaScrollOnFocus,
+    E2eTextareaStates
+} from '../components/textarea/e2e';
 import { E2eTimepickerStates } from '../components/timepicker/e2e';
 import { E2eTimezoneStates } from '../components/timezone/e2e';
 import { E2eToastStates } from '../components/toast/e2e';
@@ -135,6 +140,7 @@ const components = [
     E2eAccordionStates,
     E2eTextareaStates,
     E2eTextareaGrowBehavior,
+    E2eTextareaGrowMaxRows,
     E2eTextareaScrollOnFocus,
     E2eDatepickerStates,
     E2eTableStates,