fix: allow disabling mfs preload from config (#1733)

Author: achingbrain

src/core/config.js

@@ -10,7 +10,8 @@ const schema = Joi.object().keys({
   repoOwner: Joi.boolean().default(true),
   preload: Joi.object().keys({
     enabled: Joi.boolean().default(true),
-    addresses: Joi.array().items(Joi.multiaddr().options({ convert: false }))
+    addresses: Joi.array().items(Joi.multiaddr().options({ convert: false })),
+    interval: Joi.number().integer().default(30 * 1000)
   }).allow(null),
   init: Joi.alternatives().try(
     Joi.boolean(),

src/core/mfs-preload.js

@@ -5,10 +5,18 @@ const debug = require('debug')
 const log = debug('jsipfs:mfs-preload')
 log.error = debug('jsipfs:mfs-preload:error')
 
-module.exports = (self, options) => {
-  options = options || {}
+module.exports = (self) => {
+  const options = self._options.preload || {}
   options.interval = options.interval || 30 * 1000
 
+  if (!options.enabled) {
+    log('MFS preload disabled')
+    return {
+      start: (cb) => setImmediate(cb),
+      stop: (cb) => setImmediate(cb)
+    }
+  }
+
   let rootCid
   let timeoutId
 

test/core/mfs-preload.spec.js

@@ -25,20 +25,36 @@ const createMockPreload = () => {
 }
 
 describe('MFS preload', () => {
+  // CIDs returned from our mock files.stat function
+  const statCids = ['QmInitial', 'QmSame', 'QmSame', 'QmUpdated']
+  let mockPreload
+  let mockFilesStat
+  let mockIpfs
+
+  beforeEach(() => {
+    mockPreload = createMockPreload()
+    mockFilesStat = createMockFilesStat(statCids)
+    mockIpfs = {
+      files: {
+        stat: mockFilesStat
+      },
+      _preload: mockPreload,
+      _options: {
+        preload: {
+          interval: 10
+        }
+      }
+    }
+  })
+
   it('should preload MFS root periodically', function (done) {
     this.timeout(80 * 1000)
 
-    // CIDs returned from our mock files.stat function
-    const statCids = ['QmInitial', 'QmSame', 'QmSame', 'QmUpdated']
+    mockIpfs._options.preload.enabled = true
+
     // The CIDs we expect to have been preloaded
     const expectedPreloadCids = ['QmSame', 'QmUpdated']
-
-    const mockPreload = createMockPreload()
-    const mockFilesStat = createMockFilesStat(statCids)
-    const mockIpfs = { files: { stat: mockFilesStat }, _preload: mockPreload }
-
-    const interval = 10
-    const preloader = mfsPreload(mockIpfs, { interval })
+    const preloader = mfsPreload(mockIpfs)
 
     preloader.start((err) => {
       expect(err).to.not.exist()
@@ -56,4 +72,20 @@ describe('MFS preload', () => {
       })
     })
   })
+
+  it('should disable preloading MFS', function (done) {
+    mockIpfs._options.preload.enabled = false
+
+    const preloader = mfsPreload(mockIpfs)
+
+    preloader.start((err) => {
+      expect(err).to.not.exist()
+
+      setTimeout(() => {
+        expect(mockPreload.cids).to.be.empty()
+
+        done()
+      }, 500)
+    })
+  })
 })