added css loader to resolve and load .css files

[scriptmaster]

• Added css loader to resolve and load .css files @lucacasonato
• Added sccs support from deno sass https://deno.land/x/denosass@1.0.5/mod.ts
• Added scss tests

deno test -A mod_test.ts:

[native, wasm] bundle config inline import map ... ok (26ms)
[portable, wasm] bundle config inline import map ... ok (7ms)
[native, native] bundle config ref import map ... ok (21ms)
[portable, native] bundle config ref import map ... ok (5ms)
[native, wasm] bundle config ref import map ... ok (25ms)
[portable, wasm] bundle config ref import map ... ok (7ms)
[native, native] custom plugin for scheme ... ok (10ms)
[portable, native] custom plugin for scheme ... ok (4ms)
[native, wasm] custom plugin for scheme ... ok (5ms)
[portable, wasm] custom plugin for scheme ... ok (5ms)
[native, native] custom plugin for scheme with import map ... ok (26ms)
[portable, native] custom plugin for scheme with import map ... ok (5ms)
[native, wasm] custom plugin for scheme with import map ... ok (22ms)
[portable, wasm] custom plugin for scheme with import map ... ok (9ms)
[native, native] uncached data url ... ok (28ms)
[portable, native] uncached data url ... ok (9ms)
[native, wasm] uncached data url ... ok (28ms)
[portable, wasm] uncached data url ... ok (11ms)
[native, native] scss and css ... ok (45ms)
[portable, native] scss and css ... ok (5ms)
[native, wasm] scss and css ... ok (33ms)
[portable, wasm] scss and css ... ok (12ms)

ok | 108 passed | 0 failed (16s)

[scriptmaster]

@lucacasonato please review and merge

[bpevs]

This looks useful, but Deno itself doesn't even support this, does it?

This pr kinda feels outside the scope of this project; the general guidance would probably just be to use a 2nd loader, or a custom_scheme_plugin, rather than merging this into the repo. Or forking / expanding into a more comprehensive Deno-centric build system for client apps.

[omar-azmi]

EDIT: I wrote a Deno compatible package that bundles CSS files (SASS/SCSS not supported). jsr link: https://jsr.io/@oazmi/esbuild-plugin-css deno.land/x link: https://deno.land/x/esbuild_plugin_css npm link: https://www.npmjs.com/package/@oazmi/esbuild-plugin-css

Original comment: for those interested, you can write a simple css plugin to resolve css imports done inside javascript. the code is mostly copied from OP's PR.

// css_plugin.ts
import type * as esbuild from "https://deno.land/x/esbuild@v0.20.1/mod.js"
import { join } from "jsr:@std/path@0.218.2"

export const denoCssPlugin: esbuild.Plugin = {
    name: "deno_css_plugin",
    setup(build) {
        build.onResolve({ filter: /\.css/ }, (args) => {
            return { path: join(args.resolveDir, args.path) }
        })
        build.onLoad({ filter: /\.css/, namespace: "file" }, async (args: esbuild.OnLoadArgs): Promise<esbuild.OnLoadResult> => {
            const contents = await Deno.readTextFile(args.path)
            return { loader: "css", contents }
        })
    }
}

and then to use, simply place this plugin before denoPlugins()

// build.ts
import { denoPlugins } from "jsr:@luca/esbuild-deno-loader@0.9.0"
import { denoCssPlugin } from "./path/to/css_plugin.ts"

const result = await esbuild.build({
    plugins: [denoCssPlugin, ...denoPlugins()],
    /* your configs
    entryPoints: ["./src/mod.ts"],
    outdir: "./dist/",
    ...
    */
})

[scriptmaster]

@bpevs are you aware of the number of devs facing sass and node-sass related install issues, which can be easily remedied with this merge?

Anyway, I have written complete bundler that supports scss/sass/preact/react (vue, svelte and angular on the way) here:

deno install -A -f https://cdn.jsdelivr.net/gh/scriptmaster/sergeant@1.7.1/sergeant.ts

sergeant create react app

[bpevs]

@scriptmaster sass and node-sass related issues are not new to bundlers and loaders: https://github.com/webpack-contrib/sass-loader/issues/205#issuecomment-256716899

That being said, I think handling css files in a loader that is supposed to be for Deno feels improper. To me, handling non-deno related code should be handled in a separate loader. I see the issues around sass, but as mentioned in https://github.com/lucacasonato/esbuild_deno_loader/issues/129, I think the proper solution to this is figuring a better way to ignore/skip css/sass files so that they can be resolved with other loaders. Not to resolve them within deno-loader.

edit: I think something like this is useful. But I just felt like I should explain why this is out of scope of this project / why I don't expect this pr to be merged.

[hsn10]

Importing CSS import './button.css' is a very common pattern.

It works in stock esbuild. If this doesn't work in deno esbuild version people will simply drop the tool and continue using what they used before.

[nandorojo]

This snippet from @omar-azmi worked for me, thanks!

[omar-azmi]

Glad to hear that it was of use to you @nandorojo . Do note that the snippet won't be able to bundle ccs url imports (i.e. @import url("./some_file_or_url.css")). For a more complete bundling solution, I'd recommend this esbuild plugin library that I wrote: omar-azmi/esbuild-plugin-css . The library handles css url imports, in addition to giving you the option for transforming your bundled css into javascript code that is embeddable in your output javascript file. I was able to bundle microsoft's monaco-editor into a single (humongous) javascript file this way.