Patch for cheerio performance

src/module.ts

@@ -293,6 +293,15 @@ function registerSecurityNitroPlugins(nuxt: Nuxt, securityOptions: ModuleOptions
       )
     )
 
+    // Pre-process HTML into DOM tree
+    config.plugins.push(
+      normalize(
+        fileURLToPath(
+          new URL('./runtime/nitro/plugins/02a-preprocessHtml', import.meta.url)
+        )
+      )
+    )
+
     // Register nitro plugin to enable Subresource Integrity
     config.plugins.push(
       normalize(
@@ -331,6 +340,16 @@ function registerSecurityNitroPlugins(nuxt: Nuxt, securityOptions: ModuleOptions
         )
       )
     )
+
+
+    // Recombine HTML from DOM tree
+    config.plugins.push(
+      normalize(
+        fileURLToPath(
+          new URL('./runtime/nitro/plugins/99b-recombineHtml', import.meta.url)
+        )
+      )
+    )
   })
 
   // Make sure our nitro plugins will be applied last

src/runtime/nitro/plugins/02a-preprocessHtml.ts

@@ -0,0 +1,24 @@
+import { defineNitroPlugin, getRouteRules } from '#imports'
+import * as cheerio from 'cheerio'
+
+
+export default defineNitroPlugin((nitroApp) => {
+  nitroApp.hooks.hook('render:html', async (html, { event }) => {
+
+    // Exit if no need to parse HTML for this route
+    const { security } = getRouteRules(event)
+    if (!security?.sri && (!security?.headers || !security?.headers.contentSecurityPolicy)) {
+      return
+    }
+
+    type Section = 'body' | 'bodyAppend' | 'bodyPrepend' | 'head'
+    const sections = ['body', 'bodyAppend', 'bodyPrepend', 'head'] as Section[]
+    const cheerios = {} as Record<Section, ReturnType<typeof cheerio.load>[]>
+    for (const section of sections) {
+      cheerios[section] = html[section].map(element => {
+        return cheerio.load(element, null, false)
+      })
+    }
+    event.context.cheerios = cheerios
+  })
+})

src/runtime/nitro/plugins/03-subresourceIntegrity.ts

@@ -1,10 +1,10 @@
 import { useStorage, defineNitroPlugin, getRouteRules } from '#imports'
-import * as cheerio from 'cheerio'
 import { isPrerendering } from '../utils'
+import { type CheerioAPI } from 'cheerio'
+
 
 export default defineNitroPlugin((nitroApp) => {
   nitroApp.hooks.hook('render:html', async (html, { event }) => {
-
     // Exit if SRI not enabled for this route
     const { security } = getRouteRules(event)
     if (!security?.sri) {
@@ -29,10 +29,9 @@ export default defineNitroPlugin((nitroApp) => {
     // However the SRI standard provides that other elements may be added to that list in the future
     type Section = 'body' | 'bodyAppend' | 'bodyPrepend' | 'head'
     const sections = ['body', 'bodyAppend', 'bodyPrepend', 'head'] as Section[]
+    const cheerios = event.context.cheerios as Record<Section, CheerioAPI[]>
     for (const section of sections) {
-      html[section] = html[section].map(element => {
-
-        const $ = cheerio.load(element, null, false)
+      cheerios[section].forEach($ => {
         // Add integrity to all relevant script tags
         $('script').each((i, script) => {
           const scriptAttrs = $(script).attr()
@@ -68,7 +67,6 @@ export default defineNitroPlugin((nitroApp) => {
             }
           }
         })
-        return $.html()
       })
     }
   })

src/runtime/nitro/plugins/04-cspSsgHashes.ts

@@ -22,18 +22,17 @@ export default defineNitroPlugin((nitroApp) => {
     const scriptHashes: Set<string> = new Set()
     const styleHashes: Set<string> = new Set()
     const hashAlgorithm = 'sha256'
+    type Section = 'body' | 'bodyAppend' | 'bodyPrepend' | 'head'
+    const cheerios = event.context.cheerios as Record<Section, ReturnType<typeof cheerio.load>[]>
 
     // Parse HTML if SSG is enabled for this route
     if (security.ssg) {
       const { hashScripts, hashStyles } = security.ssg
 
       // Scan all relevant sections of the NuxtRenderHtmlContext
-      type Section = 'body' | 'bodyAppend' | 'bodyPrepend' | 'head'
       const sections = ['body', 'bodyAppend', 'bodyPrepend', 'head'] as Section[]
       for (const section of sections) {
-        html[section].forEach(element => {
-          const $ = cheerio.load(element, null, false)
-
+        cheerios[section].forEach($ => {
           // Parse all script tags
           if (hashScripts) {
             $('script').each((i, script) => {
@@ -103,10 +102,9 @@ export default defineNitroPlugin((nitroApp) => {
     const csp = security.headers.contentSecurityPolicy
     const headerValue = generateCspRules(csp, scriptHashes, styleHashes)
     // Insert CSP in the http meta tag
-    html.head.push(`<meta http-equiv="Content-Security-Policy" content="${headerValue}">`)
+    cheerios.head.push(cheerio.load(`<meta http-equiv="Content-Security-Policy" content="${headerValue}">`))
     // Update rules in HTTP header
     setResponseHeader(event, 'Content-Security-Policy', headerValue)
-
   })
 
   // Insert hashes in the CSP meta tag for both the script-src and the style-src policies

src/runtime/nitro/plugins/99-cspSsrNonce.ts

@@ -1,5 +1,5 @@
 import { defineNitroPlugin, getRouteRules, setResponseHeader } from '#imports'
-import * as cheerio from 'cheerio'
+import { type CheerioAPI } from 'cheerio'
 import type { ContentSecurityPolicyValue } from '~/src/module'
 import { headerStringFromObject } from '../../utils/headers'
 import { isPrerendering } from '../utils'
@@ -26,16 +26,15 @@ export default defineNitroPlugin((nitroApp) => {
       // Scan all relevant sections of the NuxtRenderHtmlContext
       type Section = 'body' | 'bodyAppend' | 'bodyPrepend' | 'head'
       const sections = ['body', 'bodyAppend', 'bodyPrepend', 'head'] as Section[]
+      const cheerios = event.context.cheerios as Record<Section, CheerioAPI[]>
       for (const section of sections) {
-        html[section] = html[section].map(element => {
-          const $ = cheerio.load(element, null, false)
+        cheerios[section].forEach($ => {
           // Add nonce to all link tags
           $('link').attr('nonce', nonce)
           // Add nonce to all script tags
           $('script').attr('nonce', nonce)
           // Add nonce to all style tags
           $('style').attr('nonce', nonce)
-          return $.html()
         })
       }
     }

src/runtime/nitro/plugins/99b-recombineHtml.ts

@@ -0,0 +1,25 @@
+import { defineNitroPlugin, getRouteRules } from '#imports'
+import { type CheerioAPI } from 'cheerio'
+
+
+export default defineNitroPlugin((nitroApp) => {
+  nitroApp.hooks.hook('render:html', (html, { event }) => {
+
+    // Exit if no need to parse HTML for this route
+    const { security } = getRouteRules(event)
+    if (!security?.sri && (!security?.headers || !security.headers.contentSecurityPolicy)) {
+      return
+    }
+
+    // Scan all relevant sections of the NuxtRenderHtmlContext
+    type Section = 'body' | 'bodyAppend' | 'bodyPrepend' | 'head'
+    const sections = ['body', 'bodyAppend', 'bodyPrepend', 'head'] as Section[]
+    const cheerios = event.context.cheerios as Record<Section, CheerioAPI[]>
+    for (const section of sections) {
+      html[section] = cheerios[section].map($ => {
+        const html = $.html()
+        return html
+      })
+    }
+  })
+})