angular / angular/components

bug(material/tree): node added with insertNode remains visible after dataSource is updated

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#29,349 0 comments 0 reactions 0 assignees View on GitHub
area: cdk/tree 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

I'm using Material Tree and `insertNode` method to create a node inside the tree menu.

### Reproduction

[StackBlitz link]( https://stackblitz.com/edit/eksxnj-u1duzq?file=src%2Fexample%2Ftree-dynamic-example.html)
Steps to reproduce:
1. Open the app and focus inside the document
2. Press `a` to add a new node using `insertNode` method
3. Press `r` to restore the data to the initial state.

### Expected Behavior

I expect that when the `data` object is populated, only the nodes passed in this array should be on the interface.

### Actual Behavior

A ghost node is added.

### Environment

```sh
@angular-devkit/architect 0.1703.7
@angular-devkit/build-angular 17.3.7
@angular-devkit/core 17.3.7
@angular-devkit/schematics 17.3.7
@angular/cli 17.3.7
@schematics/angular 17.3.7
ng-packagr 17.3.0
rxjs 7.8.1
typescript 5.4.5
webpack 5.90.3
zone.js 0.14.5
```

This is also in v18.

Contributor guide

Open the contributing guide

Research direction

Start with the linked StackBlitz reproduction at src/example/tree-dynamic-example.html and reproduce the sequence: press `a` to call insertNode, then `r` to restore the initial data. Trace how the Material Tree handles the data update after insertion; done means only the nodes in the restored data array remain visible, with no ghost node.

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
38/100

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