Merge pull request #200 from ipfs/promise

feat: Add promise based api

Author: daviddias

.travis.yml

@@ -4,6 +4,9 @@ node_js:
   - '5'
   - stable
 
+addons:
+  firefox: 'latest'
+
 before_script:
   - export DISPLAY=:99.0
   - sh -e /etc/init.d/xvfb start

README.md

@@ -49,6 +49,20 @@ If you omit the host and port, the api will parse `window.host`, and use this in
 var ipfs = window.ipfsAPI()
 ```
 
+### Using Promises
+
+If you do not pass in a callback all api functions will return a `Promise`, for example
+
+```js
+ipfs.id()
+  .then(function (id) {
+    console.log('my id is: ', id)
+  })
+```
+
+This relies on a global `Promise` object. If you are in an environemnt where that is not
+yet available you need to bring your own polyfill.
+
 #### Gotchas
 
 When using the api from script tag for things that require buffers (`ipfs.add`, for example), you will have to use either the exposed `ipfs.Buffer`, that works just like a node buffer, or use this [browser buffer](https://github.com/feross/buffer).

src/api/dht.js

@@ -11,23 +11,38 @@ module.exports = send => {
         opts = null
       }
 
-      return send('dht/get', key, opts, null, (err, res) => {
-        if (err) return cb(err)
-        if (!res) return cb(new Error('empty response'))
-        if (res.length === 0) return cb(new Error('no value returned for key'))
+      const handleResult = (done, err, res) => {
+        if (err) return done(err)
+        if (!res) return done(new Error('empty response'))
+        if (res.length === 0) return done(new Error('no value returned for key'))
 
         // Inconsistent return values in the browser vs node
         if (Array.isArray(res)) {
           res = res[0]
         }
 
         if (res.Type === 5) {
-          cb(null, res.Extra)
+          done(null, res.Extra)
         } else {
           let error = new Error('key was not found (type 6)')
-          cb(error)
+          done(error)
         }
-      })
+      }
+
+      if (typeof cb !== 'function' && typeof Promise !== 'undefined') {
+        const done = (err, res) => {
+          if (err) throw err
+          return res
+        }
+
+        return send('dht/get', key, opts)
+          .then(
+            res => handleResult(done, null, res),
+            err => handleResult(done, err)
+          )
+      }
+
+      return send('dht/get', key, opts, null, handleResult.bind(null, cb))
     },
     put (key, value, opts, cb) {
       if (typeof (opts) === 'function' && !cb) {

src/api/log.js

@@ -5,6 +5,11 @@ const ndjson = require('ndjson')
 module.exports = send => {
   return {
     tail (cb) {
+      if (typeof cb !== 'function' && typeof Promise !== 'undefined') {
+        return send('log/tail', null, {}, null, false)
+          .then(res => res.pipe(ndjson.parse()))
+      }
+
       return send('log/tail', null, {}, null, false, (err, res) => {
         if (err) return cb(err)
         cb(null, res.pipe(ndjson.parse()))

src/api/ping.js

@@ -2,6 +2,11 @@
 
 module.exports = send => {
   return function ping (id, cb) {
+    if (typeof cb !== 'function' && typeof Promise !== 'undefined') {
+      return send('ping', id, {n: 1}, null)
+        .then(res => res[1])
+    }
+
     return send('ping', id, { n: 1 }, null, function (err, res) {
       if (err) return cb(err, null)
       cb(null, res[1])

src/request-api.js

@@ -63,11 +63,6 @@ function requestAPI (config, path, args, qs, files, buffer, cb) {
   if (args) qs.arg = args
   if (files && !Array.isArray(files)) files = [files]
 
-  if (typeof buffer === 'function') {
-    cb = buffer
-    buffer = false
-  }
-
   if (qs.r) {
     qs.recursive = qs.r
     delete qs.r // From IPFS 0.4.0, it throw an error when both r and recursive are passed
@@ -116,5 +111,21 @@ function requestAPI (config, path, args, qs, files, buffer, cb) {
 // -- Interface
 
 exports = module.exports = function getRequestAPI (config) {
-  return requestAPI.bind(null, config)
+  return function (path, args, qs, files, buffer, cb) {
+    if (typeof buffer === 'function') {
+      cb = buffer
+      buffer = false
+    }
+
+    if (typeof cb !== 'function' && typeof Promise !== 'undefined') {
+      return new Promise(function (resolve, reject) {
+        requestAPI(config, path, args, qs, files, buffer, function (err, res) {
+          if (err) return reject(err)
+          resolve(res)
+        })
+      })
+    }
+
+    return requestAPI(config, path, args, qs, files, buffer, cb)
+  }
 }

test/api/add.spec.js

@@ -118,4 +118,15 @@ describe('.add', () => {
       done()
     })
   })
+
+  describe('promise', () => {
+    it('add buffer', () => {
+      let buf = new Buffer(testfile)
+      return apiClients['a'].add(buf)
+        .then(res => {
+          expect(res).to.have.length(1)
+          expect(res[0]).to.have.property('Hash', 'Qma4hjFTnCasJ8PVp3mZbZK5g2vGDT4LByLJ7m8ciyRFZP')
+        })
+    })
+  })
 })

test/api/block.spec.js

@@ -34,4 +34,34 @@ describe('.block', () => {
       done()
     })
   })
+
+  describe('promise', () => {
+    it('block.put', () => {
+      return apiClients['a'].block.put(blorb)
+        .then(res => {
+          expect(res).to.have.a.property('Key', 'QmPv52ekjS75L4JmHpXVeuJ5uX2ecSfSZo88NSyxwA3rAQ')
+        })
+    })
+
+    it('block.get', done => {
+      return apiClients['a'].block.get(blorbKey)
+        .then(res => {
+          let buf = ''
+          res
+            .on('data', function (data) { buf += data })
+            .on('end', function () {
+              expect(buf).to.be.equal('blorb')
+              done()
+            })
+        })
+    })
+
+    it('block.stat', () => {
+      return apiClients['a'].block.stat(blorbKey)
+        .then(res => {
+          expect(res).to.have.property('Key')
+          expect(res).to.have.property('Size')
+        })
+    })
+  })
 })

test/api/cat.spec.js

@@ -46,4 +46,20 @@ describe('.cat', () => {
       })
     })
   })
+
+  describe('promise', () => {
+    it('cat', done => {
+      return apiClients['a'].cat('Qma4hjFTnCasJ8PVp3mZbZK5g2vGDT4LByLJ7m8ciyRFZP')
+        .then(res => {
+          let buf = ''
+          res
+            .on('error', err => { throw err })
+            .on('data', data => buf += data)
+            .on('end', () => {
+              expect(buf).to.be.equal(testfile.toString())
+              done()
+            })
+        })
+    })
+  })
 })

test/api/commands.spec.js

@@ -8,4 +8,13 @@ describe('.commands', () => {
       done()
     })
   })
+
+  describe('promise', () => {
+    it('lists commands', () => {
+      return apiClients['a'].commands()
+      .then(res => {
+        expect(res).to.exist
+      })
+    })
+  })
 })