Philipp Spiess 4200a1ecc4
Fix slow incremental builds (especially on Windows) (#17511)
This PR fixes slow rebuilds on Windows where rebuilds go from ~2s to
~20ms.

Fixes: #16911
Fixes: #17522

## Test plan

1. Tested it on a reproduction with the following results:

Before:


https://github.com/user-attachments/assets/10c5e9e0-3c41-4e1d-95f6-ee8d856577ef

After:


https://github.com/user-attachments/assets/2c7597e9-3fff-4922-a2da-a8d06eab9047

Zooming in on the times, it looks like this:
<img width="674" alt="image"
src="https://github.com/user-attachments/assets/85eee69c-bbf6-4c28-8ce3-6dcdad74be9c"
/>

But with these changes:
<img width="719" alt="image"
src="https://github.com/user-attachments/assets/d89cefda-0711-4f84-bfaf-2bea11977bf7"
/>

We also tested this on Windows with the following results:
Before:
<img width="961" alt="image"
src="https://github.com/user-attachments/assets/3a42f822-f103-4598-9a91-e659ae09800c"
/>

After:
<img width="956" alt="image"
src="https://github.com/user-attachments/assets/05b6b6bc-d107-40d1-a207-3638aba3fc3a"
/>


[ci-all]

---------

Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
2025-04-03 17:13:15 +02:00

111 lines
2.9 KiB
TypeScript

import { css, html, js, json, test } from '../utils'
test(
'webpack + PostCSS (watch)',
{
fs: {
'package.json': json`
{
"main": "./src/index.js",
"browser": "./src/index.js",
"dependencies": {
"css-loader": "^6",
"postcss": "^8",
"postcss-loader": "^7",
"webpack": "^5",
"webpack-cli": "^5",
"mini-css-extract-plugin": "^2",
"tailwindcss": "workspace:^",
"@tailwindcss/postcss": "workspace:^"
}
}
`,
'postcss.config.js': js`
/** @type {import('postcss-load-config').Config} */
module.exports = {
plugins: {
'@tailwindcss/postcss': {},
},
}
`,
'webpack.config.js': js`
let MiniCssExtractPlugin = require('mini-css-extract-plugin')
module.exports = {
output: {
clean: true,
},
plugins: [new MiniCssExtractPlugin()],
module: {
rules: [
{
test: /.css$/i,
use: [MiniCssExtractPlugin.loader, 'css-loader', 'postcss-loader'],
},
],
},
}
`,
'src/index.js': js`import './index.css'`,
'src/index.html': html`
<div class="flex"></div>
`,
'src/index.css': css`
@import 'tailwindcss/theme';
@import 'tailwindcss/utilities';
`,
'src/unrelated.module.css': css`
.module {
color: var(--color-blue-500);
}
`,
},
},
async ({ fs, spawn, exec, expect }) => {
// Generate the initial build so output CSS files exist on disk
await exec('pnpm webpack --mode=development')
// NOTE: We are writing to an output CSS file which is not being ignored by
// `.gitignore` nor marked with `@source not`. This should not result in an
// infinite loop.
let process = await spawn('pnpm webpack --mode=development --watch')
await process.onStdout((m) => m.includes('compiled successfully in'))
expect(await fs.dumpFiles('./dist/*.css')).toMatchInlineSnapshot(`
"
--- ./dist/main.css ---
:root, :host {
--color-blue-500: oklch(62.3% 0.214 259.815);
}
.flex {
display: flex;
}
"
`)
await fs.write(
'src/unrelated.module.css',
css`
.module {
color: var(--color-blue-500);
background-color: var(--color-red-500);
}
`,
)
await process.onStdout((m) => m.includes('compiled successfully in'))
expect(await fs.dumpFiles('./dist/*.css')).toMatchInlineSnapshot(`
"
--- ./dist/main.css ---
:root, :host {
--color-red-500: oklch(63.7% 0.237 25.331);
--color-blue-500: oklch(62.3% 0.214 259.815);
}
.flex {
display: flex;
}
"
`)
},
)