Skip to content

perf(css): only run postcss when needed #19061

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
sapphi-red merged 6 commits into from
Jan 24, 2025
Merged

perf(css): only run postcss when needed #19061

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
643d152
perf: only run postcss when needed
sapphi-red Dec 24, 2024
4c777ac
chore: merge main
sapphi-red Dec 25, 2024
76e3da4
refactor: use `hasUrl`
sapphi-red Jan 7, 2025
f177476
refactor: check for parser
sapphi-red Jan 7, 2025
a1394bf
refactor: add type
sapphi-red Jan 7, 2025
d00ce43
chore: merge main
sapphi-red Jan 24, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
63 changes: 34 additions & 29 deletions packages/vite/src/node/plugins/css.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1271,7 +1271,6 @@ async function compileCSS(
): Promise<{
code: string
map?: SourceMapInput
ast?: PostCSS.Result
modules?: Record<string, string>
deps?: Set<string>
}> {
Expand All @@ -1280,51 +1279,49 @@ async function compileCSS(
return compileLightningCSS(id, code, environment, urlReplacer)
}

const lang = CSS_LANGS_RE.exec(id)?.[1] as CssLang | undefined
const deps = new Set<string>()

// pre-processors: sass etc.
let preprocessorMap: ExistingRawSourceMap | undefined
if (isPreProcessor(lang)) {
const preprocessorResult = await compileCSSPreprocessors(
environment,
id,
lang,
code,
workerController,
)
code = preprocessorResult.code
preprocessorMap = preprocessorResult.map
preprocessorResult.deps?.forEach((dep) => deps.add(dep))
}

const { modules: modulesOptions, devSourcemap } = config.css
const isModule = modulesOptions !== false && cssModuleRE.test(id)
// although at serve time it can work without processing, we do need to
// crawl them in order to register watch dependencies.
const needInlineImport = code.includes('@import')
const hasUrl = cssUrlRE.test(code) || cssImageSetRE.test(code)
const lang = CSS_LANGS_RE.exec(id)?.[1] as CssLang | undefined
const postcssConfig = await resolvePostcssConfig(
environment.getTopLevelConfig(),
)

// 1. plain css that needs no processing
// postcss processing is not needed
if (
lang === 'css' &&
lang !== 'sss' &&
!postcssConfig &&
!isModule &&
!needInlineImport &&
!hasUrl
) {
return { code, map: null }
return { code, map: preprocessorMap ?? null, deps }
}
Copy link
Member Author

@sapphi-red sapphi-red Dec 24, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

With this PR, If the preprocessor removed all @import, we might be able to return at this line. (previously postcss was run)


let modules: Record<string, string> | undefined
const deps = new Set<string>()

// 2. pre-processors: sass etc.
let preprocessorMap: ExistingRawSourceMap | undefined
if (isPreProcessor(lang)) {
const preprocessorResult = await compileCSSPreprocessors(
environment,
id,
lang,
code,
workerController,
)
code = preprocessorResult.code
preprocessorMap = preprocessorResult.map
preprocessorResult.deps?.forEach((dep) => deps.add(dep))
}

// 3. postcss
// postcss
const atImportResolvers = getAtImportResolvers(
environment.getTopLevelConfig(),
)
const postcssOptions = postcssConfig?.options ?? {}
const postcssPlugins = postcssConfig?.plugins.slice() ?? []

if (needInlineImport) {
Expand Down Expand Up @@ -1386,7 +1383,13 @@ async function compileCSS(
)
}

if (urlReplacer) {
if (
urlReplacer &&
// if there's an @import, we need to add this plugin
// regradless of whether it contains url() or image-set(),
// because we don't know the content referenced by @import
(needInlineImport || cssUrlRE.test(code) || cssImageSetRE.test(code))
) {
postcssPlugins.push(
UrlRewritePostcssPlugin({
replacer: urlReplacer,
Copy link
Member Author

@sapphi-red sapphi-red Dec 24, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

UrlRewritePostcssPlugin was always pushed, so postcss was ran always.

Expand All @@ -1395,6 +1398,8 @@ async function compileCSS(
)
}

let modules: Record<string, string> | undefined

if (isModule) {
postcssPlugins.unshift(
(await importPostcssModules()).default({
Expand Down Expand Up @@ -1428,7 +1433,7 @@ async function compileCSS(
)
}

if (!postcssPlugins.length) {
if (lang !== 'sss' && !postcssPlugins.length) {
Copy link
Member Author

@sapphi-red sapphi-red Dec 24, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This lang !== 'sss' was not needed because !postcssPlugins.length was always false.

Copy link
Member

@bluwy bluwy Jan 2, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'm a bit confused about this part. Isn't sugarss support added as a postcss plugin, so postcssPlugins.length should be at least one?

Copy link
Member Author

@sapphi-red sapphi-red Jan 3, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It's because sugarss is a parser and not a plugin.

vite/packages/vite/src/node/plugins/css.ts

Line 1447 in da0caf5

parser: lang === 'sss' ? loadSss(config.root) : postcssOptions.parser,

Now that you mentioned about it, I think we should change this condition to lang !== 'sss' && !postcssOptions.parser && !postcssPlugins.length.

Copy link
Member

@bluwy bluwy Jan 3, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ah I didn't know it's a parser. Yeah I think checking for parser seems better too.

Copy link
Member Author

@sapphi-red sapphi-red Jan 7, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Updated 👍

return {
code,
map: preprocessorMap,
Expand All @@ -1440,6 +1445,8 @@ async function compileCSS(
try {
const source = removeDirectQuery(id)
const postcss = await importPostcss()
const postcssOptions = postcssConfig?.options ?? {}

// postcss is an unbundled dep and should be lazy imported
postcssResult = await postcss.default(postcssPlugins).process(code, {
...postcssOptions,
Expand Down Expand Up @@ -1509,7 +1516,6 @@ async function compileCSS(

if (!devSourcemap) {
return {
ast: postcssResult,
Copy link
Member Author

@sapphi-red sapphi-red Dec 24, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

ast was not used anywhere.

code: postcssResult.css,
map: { mappings: '' },
modules,
Expand All @@ -1527,7 +1533,6 @@ async function compileCSS(
)

return {
ast: postcssResult,
code: postcssResult.css,
map: combineSourcemapsIfExists(cleanUrl(id), postcssMap, preprocessorMap),
modules,
Expand Down
8 changes: 4 additions & 4 deletions playground/css-sourcemap/__tests__/css-sourcemap.spec.ts
View file
Open in desktop
Copy link
Member Author

@sapphi-red sapphi-red Dec 24, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The sourcemaps changed because postcss does not run on these files anymore.

Original file line number Diff line number Diff line change
Expand Up @@ -138,8 +138,8 @@ describe.runIf(isServe)('serve', () => {
const map = extractSourcemap(css)
expect(formatSourcemapForSnapshot(map)).toMatchInlineSnapshot(`
{
"ignoreList": [],
"mappings": "AAGE;EACE,UCJM",
"mappings": "AAGE;EACE,OCJM",
"sourceRoot": "",
"sources": [
"/root/imported.sass",
"/root/imported-nested.sass",
Expand Down Expand Up @@ -186,7 +186,7 @@ describe.runIf(isServe)('serve', () => {
expect(formatSourcemapForSnapshot(map)).toMatchInlineSnapshot(`
{
"ignoreList": [],
"mappings": "AACE;EACE",
"mappings": "AACE,SAAC;EACC",
"sources": [
"/root/imported.less",
],
Expand All @@ -209,7 +209,7 @@ describe.runIf(isServe)('serve', () => {
expect(formatSourcemapForSnapshot(map)).toMatchInlineSnapshot(`
{
"ignoreList": [],
"mappings": "AACE;EACE,cAAM",
"mappings": "AACE;EACE,OAAM,QAAN",
"sources": [
"/root/imported.styl",
],
Expand Down
Loading