Add support for Angular Language Service in HTML files

[gbrlsnchs]

Name: Angular Language Service
URL: https://angular.io/guide/language-service

Angular Language Service is a plugin for TSServer that enables autocompletion in HTML for Angular component files using the @angular/language-service NPM package.

In this case, as it is a plugin of TSServer, I think the solution would be that in projects that have angular.json files in their root, TSServer should be enabled for HTML files.

[WooterTheTroubleshooter]

Actually for external templates, it seems you need to use the separate server, not the plugin. https://github.com/angular/vscode-ng-language-service/tree/master/server

Which in turn, starts a separate tsserver + plugin.
However currently the server seems outdated.

npm WARN notsup Unsupported engine for @angular/language-server@0.1001.1: wanted: {"node":">=10.9.0 <13.0.0"} (current: {"node":"15.1.0","npm":"6.14.8"})
npm WARN notsup Not compatible with your version of node/npm: @angular/language-server@0.1001.1

Trying anyway results in:
Error: Failed to resolve 'typescript/lib/tsserverlibrary' with minimum version '3.9' from []

(Just posting my notes, haven't looked into it further, yet.)

[w0rp]

I would love to know how to get this to work with as little friction as possible. I would like it to just work automatically, provided you have the right configuration. I'm using Angular for my day job, and at the moment all of our templates are embedded in component.ts files, so we get the benefits of type checking by virtue of working with TypeScript files only... for now. At some point I'll need to have support for checking HTML files in Angular projects too. (Though I do kind of like keeping the templates in the TypeScript component files and keeping them very small.)

[Guergeiro]

Any ETA on this? I'm trying to move from coc to ale (way faster from my experience so far). I normally work with angular and this really is a really good feature for my use case.

[w0rp]

I'll give it a go. I don't need it for work just yet, but eventually I will need it.

[w0rp]

It looks like the first stable LSP server version is for Angular 11, so that's probably the minimum version we should try to support. I got as far as figuring that out before I had to stop looking for now.

[w0rp]

I've got a working version of it locally now I tested with my own codebase, and it also led to fixing a breaking change in Language Server Protocol where different data can be returned for "go to X" requests, or maybe just a bug in the Angular language server where it returns that data without the client saying it can support it. I'll add some tests for it when I next have some spare time and add it in. As I thought, Angular 11 will be the minimum version I'll support because it seems to be the first version that's stable enough to be worth supporting.

[w0rp]

I've added a linter file for the Angular language server now. Only Angular 11 and up are supported, and you need to install the language server.

npm install --save-dev @angular/language-server

It works pretty well with my work codebase. Enjoy!