angular / angular/components

bug(CdkListbox): cdkOption requires additional event to rerender after list of options changed

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#28,828 1 comment 0 reactions 0 assignees View on GitHub
area: cdk/listbox 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

When any **option was selected** in the list and than user filtered them somehow and back to the initial list, **that selected option** will be rendered incorrectly.

https://github.com/angular/components/assets/13451032/4392054a-68e3-439e-a250-0084c943d37d

P.S. A bit similar problem was there: https://github.com/angular/components/issues/28557

### Reproduction

StackBlitz link: https://stackblitz.com/edit/stackblitz-starters-xvgkha?file=src%2Findex.html,src%2Fmain.ts
Steps to reproduce:
1. Click **"Ron"** option (it becomes true)
2. Type in `input` letter **"J"**
3. Remove letter **"J"**
4. See that option **"Ron"** is false.
5. Type in input letter **"R"** or click outside `input`
6. See that option **"Ron"** is true.

### Expected Behavior

Option should be rendered immediately based on its internal state (`isSelected()/isActive()`).

### Actual Behavior

Option requires one more event to be rendered based on its internal state (`isSelected()/isActive()`).

### Environment

- Angular: 17
- CDK/Material: 17.3.3
- Browser(s): Chrome and Safari
- Operating System (e.g. Windows, macOS, Ubuntu):

Contributor guide

Open the contributing guide

Research direction

Start with the linked StackBlitz reproduction, especially src/index.html and src/main.ts, and follow the filtering steps for CdkListbox and cdkOption. Compare the selected option's rendered state after the list returns to its initial contents. Done means the option is rendered immediately from its internal isSelected()/isActive() state without requiring another input or focus event.

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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