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

从 esbuild application builder 及其 file-loader 处理开始，以 angular.json 和复现的 ng build --deploy-url=/my-deploy-url/ 命令作为切入点。验证导入的 SVG URL 是如何生成的，并将其与预期的 deploy URL 行为进行比较；当导入文件的 URL 在无需运行时 workarounds 的情况下包含配置的 deploy URL 时，即表示完成。

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            │
└───────────────────────────────────┴───────────────────┴───────────────────┘