fix: prevent 404 on code viewer direct URL access (#630)

Author: onmax

server/middleware/well-known-skills.ts

@@ -0,0 +1,69 @@
+import type { H3Event } from 'h3'
+import * as v from 'valibot'
+import { PackageRouteParamsSchema } from '#shared/schemas/package'
+import { SkillNameSchema } from '#shared/schemas/skills'
+import { CACHE_MAX_AGE_ONE_HOUR, CACHE_MAX_AGE_ONE_YEAR } from '#shared/utils/constants'
+
+/**
+ * Serves /.well-known/skills endpoints for `npx skills add` CLI.
+ * Middleware pattern allows non-matching paths to pass through to Nuxt.
+ */
+export default defineEventHandler(event => {
+  const url = getRequestURL(event)
+  const match = url.pathname.match(/^\/(.+?)\/\.well-known\/skills\/(.*)$/)
+  if (!match) return
+
+  return cachedHandler(event)
+})
+
+const cachedHandler = defineCachedEventHandler(
+  async (event: H3Event) => {
+    const url = getRequestURL(event)
+    const match = url.pathname.match(/^\/(.+?)\/\.well-known\/skills\/(.*)$/)!
+    const [, pkgPath, skillsPath] = match
+
+    const validated = v.parse(PackageRouteParamsSchema, {
+      packageName: pkgPath,
+      version: undefined,
+    })
+    const packument = await fetchNpmPackage(validated.packageName)
+    const version = packument['dist-tags']?.latest
+    if (!version) throw createError({ statusCode: 404, message: 'No latest version found' })
+
+    if (skillsPath === 'index.json' || skillsPath === '') {
+      const fileTree = await getPackageFileTree(validated.packageName, version)
+      const skillDirs = findSkillDirs(fileTree.tree)
+      const skills = skillDirs.length
+        ? await fetchSkillsListForWellKnown(
+            validated.packageName,
+            version,
+            skillDirs.map(s => s.name),
+          )
+        : []
+      setHeader(event, 'Cache-Control', `public, max-age=${CACHE_MAX_AGE_ONE_HOUR}`)
+      setHeader(event, 'Content-Type', 'application/json')
+      return { skills }
+    }
+
+    const [skillName, ...rest] = skillsPath!.split('/')
+    const fileName = rest.join('/')
+    if (fileName === 'SKILL.md' || fileName === '') {
+      const content = await fetchSkillFile(
+        validated.packageName,
+        version,
+        `skills/${v.parse(SkillNameSchema, skillName)}/SKILL.md`,
+      )
+      setHeader(event, 'Cache-Control', `public, max-age=${CACHE_MAX_AGE_ONE_YEAR}, immutable`)
+      setHeader(event, 'Content-Type', 'text/markdown; charset=utf-8')
+      return content
+    }
+
+    throw createError({ statusCode: 404, message: 'File not found' })
+  },
+  {
+    maxAge: CACHE_MAX_AGE_ONE_HOUR,
+    swr: true,
+    getKey: (event: H3Event) =>
+      `well-known-skills:v1:${getRequestURL(event).pathname.replace(/\/+$/, '')}`,
+  },
+)