chore: callbacks -> async / await

This is part of the Awesome Endeavour: Async Iterators
ipfs/js-ipfs#1670

BREAKING CHANGE: All places in the API that used callbacks are now replaced with async/await

Author: dirkmc

README.md

@@ -72,31 +72,20 @@ const repo = new IPFSRepo('example')
 
 // create a block
 const data = new Buffer('hello world')
-multihashing(data, 'sha2-256', (err, multihash) => {
-  if (err) {
-    throw err
-  }
-
-  const cid = new CID(multihash)
-  const block = new Block(data, cid)
-
-  // create a service
-  const bs = new BlockService(repo)
-
-  // add the block, then retrieve it
-  bs.put(block, (err) => {
-    if (err) {
-      throw err
-    }
-    bs.get(cid, (err, b) => {
-      if (err) {
-        throw err
-      }
-      console.log(block.data.toString() === b.data.toString())
-      // => true
-    })
-  })
-})
+const multihash = await multihashing(data, 'sha2-256')
+
+const cid = new CID(multihash)
+const block = new Block(data, cid)
+
+// create a service
+const service = new BlockService(repo)
+
+// add the block, then retrieve it
+await service.put(block)
+
+const result = await service.get(cid)
+console.log(block.data.toString() === result.data.toString())
+// => true
 ```
 
 ### Browser: Browserify, Webpack, other bundlers

package.json

@@ -34,19 +34,18 @@
     "chai": "^4.2.0",
     "cids": "~0.5.7",
     "dirty-chai": "^2.0.1",
+    "fs-extra": "^8.0.1",
     "ipfs-block": "~0.8.0",
-    "ipfs-repo": "~0.26.2",
+    "ipfs-repo": "~0.27.0",
     "lodash": "^4.17.11",
-    "multihashing-async": "~0.5.2",
-    "ncp": "^2.0.0",
-    "rimraf": "^2.6.3"
+    "multihashing-async": "~0.7.0"
   },
   "engines": {
     "node": ">=6.0.0",
     "npm": ">=3.0.0"
   },
   "dependencies": {
-    "async": "^2.6.2"
+    "streaming-iterables": "^4.0.2"
   },
   "contributors": [
     "David Dias <[email protected]>",

src/index.js

@@ -1,6 +1,6 @@
 'use strict'
 
-const asyncMap = require('async/map')
+const { map } = require('streaming-iterables')
 
 /**
  * BlockService is a hybrid block datastore. It stores data in a local
@@ -54,73 +54,71 @@ class BlockService {
    * Put a block to the underlying datastore.
    *
    * @param {Block} block
-   * @param {function(Error)} callback
-   * @returns {void}
+   * @returns {Promise}
    */
-  put (block, callback) {
+  put (block) {
     if (this.hasExchange()) {
-      this._bitswap.put(block, callback)
+      return this._bitswap.put(block)
     } else {
-      this._repo.blocks.put(block, callback)
+      return this._repo.blocks.put(block)
     }
   }
 
   /**
    * Put a multiple blocks to the underlying datastore.
    *
    * @param {Array<Block>} blocks
-   * @param {function(Error)} callback
-   * @returns {void}
+   * @returns {Promise}
    */
-  putMany (blocks, callback) {
+  putMany (blocks) {
     if (this.hasExchange()) {
-      this._bitswap.putMany(blocks, callback)
+      return this._bitswap.putMany(blocks)
     } else {
-      this._repo.blocks.putMany(blocks, callback)
+      return this._repo.blocks.putMany(blocks)
     }
   }
 
   /**
    * Get a block by cid.
    *
    * @param {CID} cid
-   * @param {function(Error, Block)} callback
-   * @returns {void}
+   * @returns {Promise<Block>}
    */
-  get (cid, callback) {
+  get (cid) {
     if (this.hasExchange()) {
-      this._bitswap.get(cid, callback)
+      return this._bitswap.get(cid)
     } else {
-      this._repo.blocks.get(cid, callback)
+      return this._repo.blocks.get(cid)
     }
   }
 
   /**
    * Get multiple blocks back from an array of cids.
    *
    * @param {Array<CID>} cids
-   * @param {function(Error, Block)} callback
-   * @returns {void}
+   * @returns {Iterator<Block>}
    */
-  getMany (cids, callback) {
+  getMany (cids) {
     if (!Array.isArray(cids)) {
-      callback(new Error('first arg must be an array of cids'))
-    } else if (this.hasExchange()) {
-      this._bitswap.getMany(cids, callback)
+      throw new Error('first arg must be an array of cids')
+    }
+
+    if (this.hasExchange()) {
+      return this._bitswap.getMany(cids)
     } else {
-      asyncMap(cids, (cid, cb) => this._repo.blocks.get(cid, cb), callback)
+      const getRepoBlocks = map((cid) => this._repo.blocks.get(cid))
+      return getRepoBlocks(cids)
     }
   }
 
   /**
    * Delete a block from the blockstore.
    *
    * @param {CID} cid
-   * @param {function(Error)} callback
-   * @return {void}
+   * @returns {Promise}
    */
-  delete (cid, callback) {
-    this._repo.blocks.delete(cid, callback)
+  delete (cid) {
+    return this._repo.blocks.delete(cid)
   }
 }