perf: sort icon collections once when resolving names

src/runtime/components/resolve-name.ts

@@ -0,0 +1,38 @@
+import { computed, reactive, toRaw } from 'vue'
+import type { NuxtIconRuntimeOptions } from '../../types'
+
+const HYPHEN = 45
+
+const sortedCollectionsCache = new WeakMap<string[], { readonly value: string[] }>()
+
+export function getSortedCollections(collections: string[] | null | undefined): string[] {
+  if (!collections)
+    return []
+  const key = toRaw(collections)
+  let sorted = sortedCollectionsCache.get(key)
+  if (!sorted) {
+    const sort = (source: string[]) => [...source].sort((a, b) => b.length - a.length)
+    // App config is cloned per request on the server, but reactive and updated in place on the client (HMR, `updateAppConfig`)
+    sorted = import.meta.client ? computed(() => sort(reactive(key))) : { value: sort(key) }
+    sortedCollectionsCache.set(key, sorted)
+  }
+  return sorted.value
+}
+
+export function resolveName(name: string, options: Pick<NuxtIconRuntimeOptions, 'cssSelectorPrefix' | 'aliases' | 'collections'>): string {
+  const bare = name.startsWith(options.cssSelectorPrefix)
+    ? name.slice(options.cssSelectorPrefix.length)
+    : name
+  const resolved = options.aliases?.[bare] || bare
+
+  // Disambiguate collection
+  // e.g. `simple-icons-github` -> `simple-icons:github`
+  if (!resolved.includes(':')) {
+    const collection = getSortedCollections(options.collections)
+      .find(c => resolved.charCodeAt(c.length) === HYPHEN && resolved.startsWith(c))
+    return collection
+      ? collection + ':' + resolved.slice(collection.length + 1)
+      : resolved
+  }
+  return resolved
+}

src/runtime/components/shared.ts

@@ -4,6 +4,7 @@ import type { IconifyIcon } from '@iconify/types'
 import type { NuxtIconRuntimeOptions } from '../../types'
 import { useAppConfig } from '#imports'
 import { init as initClientBundle } from '#build/nuxt-icon-client-bundle'
+import { resolveName } from './resolve-name'
 
 export { initClientBundle }
 
@@ -47,25 +48,8 @@ export async function loadIcon(name: string, timeout: number): Promise<Required<
 
 export function useResolvedName(getName: () => string) {
   const options = useAppConfig().icon as NuxtIconRuntimeOptions
-  const collections = (options.collections || []).sort((a, b) => b.length - a.length)
 
-  return computed(() => {
-    const name = getName()
-    const bare = name.startsWith(options.cssSelectorPrefix)
-      ? name.slice(options.cssSelectorPrefix.length)
-      : name
-    const resolved = options.aliases?.[bare] || bare
-
-    // Disambiguate collection
-    // e.g. `simple-icons-github` -> `simple-icons:github`
-    if (!resolved.includes(':')) {
-      const collection = collections.find(c => resolved.startsWith(c + '-'))
-      return collection
-        ? collection + ':' + resolved.slice(collection.length + 1)
-        : resolved
-    }
-    return resolved
-  })
+  return computed(() => resolveName(getName(), options))
 }
 
 export function resolveCustomizeFn(

test/resolve-name.test.ts

@@ -0,0 +1,82 @@
+import { computed, reactive } from 'vue'
+import { describe, expect, it } from 'vitest'
+import { getSortedCollections, resolveName } from '../src/runtime/components/resolve-name'
+
+function createOptions(collections: string[] | null, aliases: Record<string, string> = {}) {
+  return { cssSelectorPrefix: 'i-', aliases, collections }
+}
+
+describe('resolveName', () => {
+  it('keeps names that already contain a collection separator', () => {
+    expect(resolveName('i-simple-icons:github', createOptions(['simple-icons']))).toBe('simple-icons:github')
+  })
+
+  it('resolves a bare name against the longest matching collection', () => {
+    const options = createOptions(['simple', 'simple-icons', 'si'])
+    expect(resolveName('i-simple-icons-github', options)).toBe('simple-icons:github')
+    expect(resolveName('simple-icons-github', options)).toBe('simple-icons:github')
+    expect(resolveName('i-simple-foo', options)).toBe('simple:foo')
+    expect(resolveName('i-si-foo', options)).toBe('si:foo')
+  })
+
+  it('requires a hyphen after the collection name', () => {
+    const options = createOptions(['simple', 'si'])
+    expect(resolveName('i-simpleicons', options)).toBe('simpleicons')
+    expect(resolveName('i-si', options)).toBe('si')
+  })
+
+  it('resolves aliases before matching collections', () => {
+    expect(resolveName('i-github', createOptions(['simple-icons'], { github: 'simple-icons-github' }))).toBe('simple-icons:github')
+  })
+
+  it('keeps bare names without a matching collection', () => {
+    expect(resolveName('i-unknown-icon', createOptions(['simple-icons']))).toBe('unknown-icon')
+    expect(resolveName('i-unknown-icon', createOptions(null))).toBe('unknown-icon')
+  })
+
+  it('does not reorder the configured collections', () => {
+    const collections = ['simple', 'simple-icons', 'si']
+    resolveName('i-simple-icons-github', createOptions(collections))
+    expect(collections).toEqual(['simple', 'simple-icons', 'si'])
+  })
+
+  it('updates computed names when reactive collections change in place', () => {
+    const options = reactive(createOptions(['simple', 'foo']))
+    const first = computed(() => resolveName('i-simple-icons-github', options))
+    const second = computed(() => resolveName('i-simple-icons-github', options))
+    expect(first.value).toBe('simple:icons-github')
+    expect(second.value).toBe('simple:icons-github')
+
+    options.collections![1] = 'simple-icons'
+    expect(first.value).toBe('simple-icons:github')
+    expect(second.value).toBe('simple-icons:github')
+  })
+
+  it('updates computed names when collections first resolved as a plain array change', () => {
+    const collections = ['simple', 'foo']
+    expect(resolveName('i-simple-icons-github', createOptions(collections))).toBe('simple:icons-github')
+
+    const options = reactive(createOptions(collections))
+    const name = computed(() => resolveName('i-simple-icons-github', options))
+    expect(name.value).toBe('simple:icons-github')
+
+    options.collections![1] = 'simple-icons'
+    expect(name.value).toBe('simple-icons:github')
+  })
+
+  it('updates computed names when reactive collections grow', () => {
+    const options = reactive(createOptions(['simple']))
+    const name = computed(() => resolveName('i-simple-icons-github', options))
+    expect(name.value).toBe('simple:icons-github')
+
+    options.collections!.push('simple-icons')
+    expect(name.value).toBe('simple-icons:github')
+  })
+})
+
+describe('getSortedCollections', () => {
+  it('sorts each collections array once', () => {
+    const collections = ['simple', 'simple-icons']
+    expect(getSortedCollections(collections)).toBe(getSortedCollections(collections))
+  })
+})

vitest.config.ts

@@ -1,6 +1,9 @@
 import { defineConfig } from 'vitest/config'
 
 export default defineConfig({
+  define: {
+    'import.meta.client': 'true',
+  },
   test: {
     exclude: ['playgrounds/**', 'node_modules/**'],
   },