use HEAD for exists

Author: pooya parsa

README.md

@@ -71,8 +71,9 @@ fs.readFile('/test/file.txt').then((contents) => {
 
 ### Options
 
-- `endpoint`:   Address endpoint of server
-- `maxAge`:     Time to keep requests in cache
+#### `endpoint`
+
+Required. HTTP URL of server.
 
 ## License
 

lib/client.js

@@ -1,10 +1,11 @@
 const fetch = require('node-fetch')
-const pMemoize = require('p-memoize')
 
 module.exports = class HTTPFSClient {
-  constructor ({ endpoint, maxAge = 1000 }) {
-    this.endpoint = endpoint.replace(/\/$/, '')
-    this._request = pMemoize(this._request, { maxAge })
+  constructor (options = {}) {
+    if (!options.endpoint) {
+      throw new Error('Missing required option `endpoint`')
+    }
+    this.endpoint = options.endpoint.replace(/\/$/, '')
   }
 
   _url (path) {
@@ -18,11 +19,11 @@ module.exports = class HTTPFSClient {
   }
 
   async exists (path) {
-    const res = await this._request(path)
+    const res = await this._request(path, { method: 'HEAD' })
     switch (res.status) {
       case 200: return true
       case 404: return false
-      default: throw new Error('Invalid status ' + res.status)
+      default: throw new Error('Unexpected status ' + res.status)
     }
   }
 

lib/middleware.js

@@ -12,6 +12,11 @@ module.exports = function HTTPFSMiddleware (mfs) {
       return res.end('No such a file or directory: ' + resourcePath)
     }
 
+    // End response for HEAD requests
+    if (req.method === 'HEAD') {
+      return res.end()
+    }
+
     // Directory listing
     if (stat.isDirectory()) {
       return res.end(`

package.json

@@ -33,7 +33,6 @@
   },
   "dependencies": {
     "errno": "^0.1.7",
-    "node-fetch": "^2.3.0",
-    "p-memoize": "^2.1.0"
+    "node-fetch": "^2.3.0"
   }
 }

yarn.lock

@@ -3633,14 +3633,6 @@ p-locate@^3.0.0:
   dependencies:
     p-limit "^2.0.0"
 
-p-memoize@^2.1.0:
-  version "2.1.0"
-  resolved "https://registry.yarnpkg.com/p-memoize/-/p-memoize-2.1.0.tgz#9ac80c8cf9373c52dfece6aae1fd2e300602898a"
-  integrity sha512-c6+a2iV4JyX0r4+i2IBJYO0r6LZAT2fg/tcB6GQbv1uzZsfsmKT7Ej5DRT1G6Wi7XUJSV2ZiP9+YEtluvhCmkg==
-  dependencies:
-    mem "^4.0.0"
-    mimic-fn "^1.0.0"
-
 p-reduce@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/p-reduce/-/p-reduce-1.0.0.tgz#18c2b0dd936a4690a529f8231f58a0fdb6a47dfa"