angular / angular/angular-cli

Spread operator slow with `application` builder

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#28,874 2 comments 0 reactions 0 assignees View on GitHub
angular/build:application area: @angular/build freq1: low severity4: memory/performance type: bug/fix
Dominant language
TypeScript
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Description

### Which @angular/* package(s) are the source of the bug?

compiler

### Is this a regression?

No

### Description

Hello,
I noticed that the spread operator is significantly slower (sometimes more than 2x slower) when using vite instead of webpack.
This doubles the loading time of some of our components.

In my [minimal reproduction](https://github.com/jopelle1/repro-angular-vite), I get an average of 10ms with webpack and 35ms with vite, with both firefox and chrome.

Is this indeed an issue with angular and is there any way to fix it?

Thank you

### Please provide a link to a minimal reproduction of the bug

https://github.com/jopelle1/repro-angular-vite

### Please provide the environment you discovered this bug in (run `ng version`)

```true
Angular CLI: 17.3.11
Node: 18.20.4
Package Manager: npm 10.8.2
OS: linux x64

Angular: 17.3.12
... animations, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router

Package Version
---------------------------------------------------------
@angular-devkit/architect 0.1703.11
@angular-devkit/build-angular 17.3.11
@angular-devkit/core 17.3.11
@angular-devkit/schematics 17.3.11
@angular/cli 17.3.11
@schematics/angular 17.3.11
rxjs 7.8.1
typescript 5.4.5
zone.js 0.14.10
```

### Anything else?

_No response_

Contributor guide

Open the contributing guide

Research direction

Start with the linked minimal reproduction, jopelle1/repro-angular-vite, and compare the spread-operator timing under the application builder using Vite and webpack. Trace the Angular compiler and application-builder paths involved, then verify that the reported performance gap is resolved or clearly characterized.

Written by the indexing model from the issue text.

Assessment

Tech stack
angular, typescript, vite
Domain
build-system, performance
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
30/100

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