feat(remote.test): perform a write/read test on a remote (#354)

See vatesfr/xo-web#1075

src/api/remote.js

@@ -1,12 +1,12 @@
 export async function getAll () {
-  return /* await */ this.getAllRemotes()
+  return this.getAllRemotes()
 }
 
 getAll.permission = 'admin'
 getAll.description = 'Gets all existing fs remote points'
 
 export async function get ({id}) {
-  return /* await */ this.getRemote(id)
+  return this.getRemote(id)
 }
 
 get.permission = 'admin'
@@ -15,8 +15,18 @@ get.params = {
   id: {type: 'string'}
 }
 
+export async function test ({id}) {
+  return this.testRemote(id)
+}
+
+test.permission = 'admin'
+test.description = 'Performs a read/write matching test on a remote point'
+test.params = {
+  id: {type: 'string'}
+}
+
 export async function list ({id}) {
-  return /* await */ this.listRemoteBackups(id)
+  return this.listRemoteBackups(id)
 }
 
 list.permission = 'admin'
@@ -26,7 +36,7 @@ list.params = {
 }
 
 export async function create ({name, url}) {
-  return /* await */ this.createRemote({name, url})
+  return this.createRemote({name, url})
 }
 
 create.permission = 'admin'

src/remote-handlers/abstract.js

@@ -7,6 +7,7 @@ import {
 
 import {
   addChecksumToReadStream,
+  getPseudoRandomBytes,
   noop,
   pCatch,
   streamToBuffer,
@@ -47,6 +48,32 @@ export default class RemoteHandlerAbstract {
     throw new Error('Not implemented')
   }
 
+  async test () {
+    const testFileName = `${Date.now()}.test`
+    const data = getPseudoRandomBytes(1024 * 1024)
+    let step = 'write'
+    try {
+      await this.outputFile(testFileName, data)
+      step = 'read'
+      const read = await this.readFile(testFileName)
+      if (data.compare(read) !== 0) {
+        throw new Error('output and input did not match')
+      }
+      return {
+        success: true
+      }
+    } catch (error) {
+      return {
+        success: false,
+        step,
+        file: testFileName,
+        error: error.message || String(error)
+      }
+    } finally {
+      this.unlink(testFileName).catch(noop)
+    }
+  }
+
   async outputFile (file, data, options) {
     return this._outputFile(file, data, {
       flags: 'wx',

src/utils.js

@@ -170,7 +170,7 @@ export function extractProperty (obj, prop) {
 
 // -------------------------------------------------------------------
 
-export const generateUnsecureToken = (n = 32) => {
+export const getPseudoRandomBytes = n => {
   const bytes = new Buffer(n)
 
   const odd = n & 1
@@ -182,9 +182,11 @@ export const generateUnsecureToken = (n = 32) => {
     bytes.writeUInt8(Math.random() * 256 | 0, n - 1)
   }
 
-  return base64url(bytes)
+  return bytes
 }
 
+export const generateUnsecureToken = (n = 32) => base64url(getPseudoRandomBytes(n))
+
 // Generate a secure random Base64 string.
 export const generateToken = (randomBytes => {
   return (n = 32) => randomBytes(n).then(base64url)

src/xo-mixins/remotes.js

@@ -54,6 +54,11 @@ export default class {
     return new Handler[type](remote)
   }
 
+  async testRemote (remote) {
+    const handler = await this.getRemoteHandler(remote)
+    return handler.test()
+  }
+
   async getAllRemotes () {
     return this._remotes.get()
   }