Adding an option to modify the non-existent root directory warning (#524)

README.md

@@ -148,6 +148,12 @@ An array of directories can be provided to serve multiple static directories
 under a single prefix. Files are served in a "first found, first served" manner,
 so list directories in order of priority. Duplicate paths will raise an error.
 
+#### `getPathNotFoundWarning`
+
+A custom function that returns a warning message to log when a specified root directory is not found.
+It receives a single argument: the path of the missing root directory.
+The function should return a string describing the missing path.
+
 #### `prefix`
 
 Default: `'/'`

index.js

@@ -19,7 +19,7 @@ send.mime.default_type = 'application/octet-stream'
 
 async function fastifyStatic (fastify, opts) {
   opts.root = normalizeRoot(opts.root)
-  checkRootPathForErrors(fastify, opts.root)
+  checkRootPathForErrors(fastify, opts.root, opts.getPathNotFoundWarning)
 
   const setHeaders = opts.setHeaders
   if (setHeaders !== undefined && typeof setHeaders !== 'function') {
@@ -417,7 +417,7 @@ function normalizeRoot (root) {
   return root
 }
 
-function checkRootPathForErrors (fastify, rootPath) {
+function checkRootPathForErrors (fastify, rootPath, getPathNotFoundWarning) {
   if (rootPath === undefined) {
     throw new Error('"root" option is required')
   }
@@ -434,18 +434,18 @@ function checkRootPathForErrors (fastify, rootPath) {
     }
 
     // check each path and fail at first invalid
-    rootPath.map((path) => checkPath(fastify, path))
+    rootPath.map((path) => checkPath(fastify, path, getPathNotFoundWarning))
     return
   }
 
   if (typeof rootPath === 'string') {
-    return checkPath(fastify, rootPath)
+    return checkPath(fastify, rootPath, getPathNotFoundWarning)
   }
 
   throw new Error('"root" option must be a string or array of strings')
 }
 
-function checkPath (fastify, rootPath) {
+function checkPath (fastify, rootPath, getPathNotFoundWarning) {
   if (typeof rootPath !== 'string') {
     throw new TypeError('"root" option must be a string')
   }
@@ -459,7 +459,11 @@ function checkPath (fastify, rootPath) {
     pathStat = statSync(rootPath)
   } catch (e) {
     if (e.code === 'ENOENT') {
-      fastify.log.warn(`"root" path "${rootPath}" must exist`)
+      const warningMessage =
+        getPathNotFoundWarning
+          ? getPathNotFoundWarning(rootPath)
+          : `"root" path "${rootPath}" must exist`
+      fastify.log.warn(warningMessage)
       return
     }
 

test/static.test.js

@@ -1,4 +1,4 @@
 'use strict'
 
 /* eslint n/no-deprecated-api: "off" */
 
@@ -1123,6 +1123,30 @@
   destination.end()
 })
 
+test('custom root not found warning', async (t) => {
+  t.plan(1)
+  const rootPath = path.join(__dirname, 'does-not-exist')
+  const pluginOptions = {
+    root: rootPath,
+    getPathNotFoundWarning: (path) => `CUSTOM "root" path "${path}" must exist`,
+  }
+  const destination = concat((data) => {
+    t.assert.deepStrictEqual(JSON.parse(data).msg, `CUSTOM "root" path "${rootPath}" must exist`)
+  })
+  const loggerInstance = pino(
+    {
+      level: 'warn'
+    },
+    destination
+  )
+  const fastify = Fastify({ loggerInstance })
+  fastify.register(fastifyStatic, pluginOptions)
+
+  await fastify.listen({ port: 0 })
+  fastify.server.unref()
+  destination.end()
+})
+
 test('send options', (t) => {
   t.plan(12)
   const pluginOptions = {

types/index.d.ts

@@ -86,6 +86,7 @@ declare namespace fastifyStatic {
 
   export interface FastifyStaticOptions extends SendOptions {
     root: string | string[] | URL | URL[];
+    getPathNotFoundWarning?: (path: string) => string;
     prefix?: string;
     prefixAvoidTrailingSlash?: boolean;
     serve?: boolean;