size regression due to host view factories generated for non-entryComponents

[IgorMinar]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[x] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

in v4 the AOT compiler generated host view factories only for entryComponents in v5.0.0.rc2 we generate them even for components that are not marked as entryComponents.

Example in aio is SearchResultsComponent, which is not marked as entryComponent. When upgrading from 5.0.0-beta.3, I noticed that we now started generating View_SearchResultsComponent_Host_0 for this component. And we do it in a way that tightly couples it with the rest of the component factories, so it can't be eliminated.

Relevant snippets of the generated code:

function View_SearchResultsComponent_Host_0(_l) {
  return viewDef(0, [ (_l()(), elementDef(0, 0, null, null, 1, "aio-search-results", [], null, null, null, View_SearchResultsComponent_0, RenderType_SearchResultsComponent)), directiveDef(1, 573440, null, 0, search_results_component_SearchResultsComponent, [], null, null) ], null, null);
}

styles_FileNotFoundSearchComponent = (createComponentFactory("aio-search-results", search_results_component_SearchResultsComponent, View_SearchResultsComponent_Host_0, {
  searchResults: "searchResults"
}

RenderType_FileNotFoundSearchComponent = createRendererType2({
  encapsulation: 2,
  styles: styles_FileNotFoundSearchComponent,
  data: {}
})

Is this expected? My understanding is that the host factories are only needed for entryComponents.

I can't estimate how significant this size regression is for aio because I'm unfortunately updating various dependencies. Due to bugs and api incompatibilities can't isolate the change just to the change of the compiler. Overall I'm looking for about 30kb size increase which might or might not contain other size regressions.

[maxkoretskyi]

I reported this behavior even for v4 in this issue

[IgorMinar]

@MaximusK in my case the issue occurs with AOT compilation

[skatterwe]

Ich kehre zurück am 01.11.2017. Ich werde Ihre Nachricht nach meiner Rückkehr beantworten. In dringenden Fällen senden Sie bitte eine Kopie Ihrer E-Mail für technische Angelegenheiten an entwicklung@arxes-tolina.de, ansonsten an info@arxes-tolina.de. Ein anderer Mitarbeiter wird sich dann Ihrer E-Mail annehmen. Hinweis: Dies ist eine automatische Antwort auf Ihre Nachricht "Re: [angular/angular] size regression due to host view factories generated for non-entryComponents (#19857)" gesendet am 23.10.2017 13:05:11. Diese ist die einzige Benachrichtigung, die Sie empfangen werden, während diese Person abwesend ist.

[alexzuza]

I tried it with 4.3.6 and it also generated Host factories for non-entryComponents

Here's piece of the corresponding code:

https://github.com/angular/angular/blob/4.3.x/packages/compiler/src/aot/compiler.ts#L303

AFAIK only Compiler in JIT mode doesn't generate such factories for non-entryComponents

https://github.com/angular/angular/blob/4.3.x/packages/compiler/src/jit/compiler.ts#L174-L199

Jit compiler only generates host factories if:

• we call compiler._compileModuleAndAllComponents
• component is part of component's entryComponents metadata
• component is part of module's entryComponents metadata
• component is part of module's bootstrap metadata

So i think it was intended to generate host factories for all component in AOT but i don't know why...

[tbosch]

@IgorMinar yes, AOT always used to generate host view factories for all components, as entryComponents could be introduced by a downstream dependency that is compiled in a separate compilation unit.

[tbosch]

The generated code here looks really wrong (it is after uglify and webpack though). The styles don't use the component factory, and the component factory should have been stored in a top level variable.

[tbosch]

@chuckjaz Steps to reproduce the incorrect code above (from @IgorMinar):

1. clone build(aio): update to @angular/core@5.0.0-rc.5 #19702
2. cd aio
3. yarn install (edited)
4. then you need to go and patch cli to disable uglify mangling
5. this is what I usually use:

            mangle: false,
            // compress: uglifyCompressOptions,
            compress: Object.assign(uglifyCompressOptions, {sequences: false}),
            // output: { ascii_only: true },
            output: { ascii_only: true, beautify: true },
            sourceMap: buildOptions.sourcemaps,
            comments: "all"
            // comments: false

1. it goes into aio/node_modules/@angular/cli/models/webpack-configs/production.js
2. find the uglify section and replace the config with the above
3. then build using:
4. ng build --target=production --environment=stable -sm --build-optimizer
5. and inspect less dist/main.*.bundle.js

[IgorMinar]

you can also disable the uglify completely by commenting it out in the webpack config. that will show you what we feed into uglify.