`deploy-url` is not prepended to imported file url when using `file` loader in `esbuild`

Start with the esbuild application builder and its file-loader handling, using angular.json and the reproduced ng build --deploy-url=/my-deploy-url/ command as entry points. Verify how an imported SVG URL is generated and compare it with the expected deploy URL behavior; done means the imported file URL includes the configured deploy URL without runtime workarounds.

Command

build

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

any webpack-based build

Description

When using Angular v21 with the new esbuild builder, and using a file loader configured for certain file types (like SVG) the --deploy-url argument passed into the build command does not get prepended to the URL returned when importing a file of the said type, and there is no way to configure it to do so.

This was properly working previously with webpack, when loading of the SVG assets was configured with a rule like this:

{
  test: /\.svg$/,
  type: 'asset/resource',
  generator: {
    filename: '[name][hash][ext]',
  },
}

Looks like with esbuild there is no way to achieve the same result, apart from manually adding deploy-url to imported URLs in runtime.

Minimal Reproduction

1. Use esbuild application builder
2. Configure angular.json to use file loader to import a certain file type:

"loader": {
  ".svg": "file"
},

3. Build application using ng build --deploy-url=/my-deploy-url/
4. Import some SVG file in the app:

import mySvgUrl from './my-image.svg';

5. Observe: mySvgUrl does not have /my-deploy-url/ prepended to it

Exception or Error

No error

Your Environment

Angular CLI       : 21.2.2
Angular           : 21.2.4
Node.js           : 24.8.0
Package Manager   : npm 11.6.0
Operating System  : darwin arm64

┌───────────────────────────────────┬───────────────────┬───────────────────┐
│ Package                           │ Installed Version │ Requested Version │
├───────────────────────────────────┼───────────────────┼───────────────────┤
│ @angular/animations               │ 21.2.4            │ 21.2.4            │
│ @angular/build                    │ 21.2.2            │ 21.2.2            │
│ @angular/cdk                      │ 21.2.2            │ 21.2.2            │
│ @angular/cli                      │ 21.2.2            │ 21.2.2            │
│ @angular/common                   │ 21.2.4            │ 21.2.4            │
│ @angular/compiler                 │ 21.2.4            │ 21.2.4            │
│ @angular/compiler-cli             │ 21.2.4            │ 21.2.4            │
│ @angular/core                     │ 21.2.4            │ 21.2.4            │
│ @angular/elements                 │ 21.2.4            │ 21.2.4            │
│ @angular/forms                    │ 21.2.4            │ 21.2.4            │
│ @angular/localize                 │ 21.2.4            │ 21.2.4            │
│ @angular/platform-browser         │ 21.2.4            │ 21.2.4            │
│ @angular/platform-browser-dynamic │ 21.2.4            │ 21.2.4            │
│ @angular/router                   │ 21.2.4            │ 21.2.4            │
│ rxjs                              │ 7.8.2             │ 7.8.2             │
│ typescript                        │ 5.9.3             │ 5.9.3             │
│ vitest                            │ 4.0.18            │ 4.0.18            │
│ zone.js                           │ 0.16.0            │ 0.16.0            │
└───────────────────────────────────┴───────────────────┴───────────────────┘