angular / angular/components

bug(cdkTextareaAutosize): Textarea does not size to fit with initial value until window is resized

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#30,652 0 comments 1 reaction 0 assignees View on GitHub
area: cdk/text-field P3
Dominant language
TypeScript
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Description

### Is this a regression?

- [ ] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

_No response_

### Description

Auto resize of the cdkTextareaAutosize directive for a textarea, which has an initial value bound to it, is not working.

### Reproduction

It is a fork of the "Auto-resizing textarea" example of https://material.angular.io/cdk/text-field/overview. I have just added ngModel with a initial value of 5 lines. This 5 lines should be displayed without scrolling (cdkAutosizeMaxRows is also set to 5).
StackBlitz link: https://stackblitz.com/edit/oktcnmdj
Steps to reproduce:
1. Start example

### Expected Behavior

Textarea should immediatly show all 5 lines without scrollbar, without resizing the window.

### Actual Behavior

Scrollbar is shown and only 3 lines are displayed
After resizing the window it works.

### Environment

- Angular: 19.2.3
- CDK/Material: 19.2.3
- Browser(s): chrome 134.0.6998.89
- Operating System (e.g. Windows, macOS, Ubuntu): Windows 11

Contributor guide

Open the contributing guide

Research direction

Start by running the linked StackBlitz reproduction and inspect the cdkTextareaAutosize directive behavior with an initial ngModel value and cdkAutosizeMaxRows set to 5. Confirm that all five lines display without a window resize and that no scrollbar appears, matching the expected behavior described in the issue.

Written by the indexing model from the issue text.

Assessment

Tech stack
angular, typescript
Domain
frontend
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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