`externalPackagesPlugin` slows down `ng serve` substantially

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#27,116 erstellt am 16.2.2024 5 Kommentare 0 Reaktionen 1 zugewiesene Person Auf GitHub ansehen

@clydin arbeitet bereits daran.

Seit 07.7.2025.

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Beschreibung

angular/build:application angular/build:dev-server area: @angular/build freq1: low needs: more info severity4: memory/performance type: bug/fix

Command

serve

Is this a regression?

Kinda, as the externalPackagesPlugin was just added via https://github.com/angular/angular-cli/pull/26923

The previous version in which this bug was not present was

Before https://github.com/angular/angular-cli/pull/26923 existed, which was part of 17.1.1, so I guess angular 17.1.0

Description

angular 17.2.0
vite/esbuild powered application builder

Using the loader option in angular.json like:

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

to support images as ecmascript imports or svgs as inline. This causes angular-cli to add the externalPackagesPlugin which is a giant hit on build performance. For our apps:

angular version	watch rebuild time	note
angular 17.1.0 `{ "loader": { ".webp": "file" } }`	`0.8 seconds`
~~angular 17.1.1 `{ "loader": { ".webp": "file" } }`~~	`6.0 seconds`
~~angular 17.2.0 `{ "loader": { ".webp": "file" } }`~~	`6.0 seconds`
angular 19.2.1 `{ "loader": { ".webp": "file" } }`	`0.8 seconds`	<- `file` doesn't regress anymore
angular 19.2.1 `{ "loader": { ".svg": "text" } }`	`6.0 seconds`	<- `text` still does

Those additional 5.2 seconds are also added to the initial build.

My rough idea of the issue is, that the externalPackagesPlugin looks at every single import that doesn't start with . or / and doesn't cache the results. So tons of @angular/..., rxjs, @ngrx/... and similar imports are resolved over and over again. Even if this function only needs 2ms to run, this quickly adds up.

Minimal Reproduction

https://github.com/sod/ng-serve-external-deps-slowdown

The only difference between the development and development-slow configurations in the angular.json are:

            "development": {
            },
            "development-slow": {
              "loader": {
                ".svg": "text"
              }
            },

Your Environment

@angular-devkit/architect       0.1702.0
@angular-devkit/build-angular   17.2.0
@angular-devkit/core            17.2.0
@angular-devkit/schematics      17.2.0
@angular/cli                    17.2.0
@schematics/angular             17.2.0
rxjs                            7.8.1
typescript                      5.3.3
zone.js                         0.14.4

Vorherrschende Sprache: TypeScript
Sterne: 27k
Forks: 11.8k
Ø Merge: 17 Std. 25 Min.
Gemergte PRs (30 T.): 183

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