fix: fix exchange in files example (#2913)

The test for this example did not go as far as downloading the file
and asserting the contents are correct - that part had not been
refactored to be async/await happy so wasn't working.

I've expanded the test to peform the download too.

Author: achingbrain

examples/exchange-files-in-browser/package.json

@@ -18,6 +18,8 @@
   },
   "dependencies": {
     "ipfs": "^0.41.0",
+    "it-all": "^1.0.1",
+    "it-last": "^1.0.1",
     "test-ipfs-example": "^1.0.0"
   },
   "browser": {

examples/exchange-files-in-browser/public/app.js

@@ -2,6 +2,8 @@
 'use strict'
 
 const IPFS = require('ipfs')
+const all = require('it-all')
+const last = require('it-last')
 const { Buffer } = IPFS
 
 // Node
@@ -53,7 +55,9 @@ async function start () {
             // '/dns4/star-signal.cloud.ipfs.team/wss/p2p-webrtc-star'
             '/ip4/127.0.0.1/tcp/13579/wss/p2p-webrtc-star'
           ]
-        }
+        },
+        // If you want to connect to the public bootstrap nodes, remove the next line
+        Bootstrap: []
       }
     })
 
@@ -219,7 +223,9 @@ async function getFile () {
 
   for await (const file of node.get(hash)) {
     if (file.content) {
-      await appendFile(file.name, hash, file.size, file.content)
+      const content = Buffer.concat(await all(file.content))
+
+      await appendFile(file.name, hash, file.size, content)
       onSuccess(`The ${file.name} file was added.`)
       $emptyRow.style.display = 'none'
     }
@@ -242,14 +248,17 @@ async function onDrop (event) {
   for (const file of files) {
     fileSize = file.size // Note: fileSize is used by updateProgress
 
-    const filesAdded = await node.add({
+    const fileAdded = await last(node.add({
       path: file.name,
       content: file
-    }, { wrapWithDirectory: true, progress: updateProgress })
+    }, {
+      wrapWithDirectory: true,
+      progress: updateProgress
+    }))
 
     // As we are wrapping the content we use that hash to keep
     // the original file name when adding it to the table
-    $cidInput.value = filesAdded[1].hash
+    $cidInput.value = fileAdded.cid.toString()
 
     resetProgress()
     await getFile()

examples/exchange-files-in-browser/test.js

@@ -1,5 +1,6 @@
 'use strict'
 
+const http = require('http')
 const fs = require('fs-extra')
 const path = require('path')
 const os = require('os')
@@ -20,6 +21,8 @@ const {
 const pkg = require('./package.json')
 const webRTCStarSigServer = require('libp2p-webrtc-star/src/sig-server')
 
+const FILE_CONTENT = 'A file with some content'
+
 async function testUI (env) {
   const proc = execa(require.resolve('test-ipfs-example/node_modules/.bin/nightwatch'), [ '--config', require.resolve('test-ipfs-example/nightwatch.conf.js'),  path.join(__dirname, 'test.js') ], {
     cwd: path.resolve(__dirname, '../'),
@@ -58,7 +61,7 @@ async function runTest () {
 
   let cid
 
-  for await (const imported of relay.api.add('A file with some content')) {
+  for await (const imported of relay.api.add(FILE_CONTENT)) {
     cid = imported.cid
   }
 
@@ -186,5 +189,19 @@ module.exports[pkg.name] = function (browser) {
   // but should both see the added file
   browser.expect.element('#file-history').text.to.contain(process.env.IPFS_CID)
 
+  if (!process.env.IPFS_ADD_FILE) {
+    // download the file from the other browser
+    browser
+      .getAttribute(`a[download=${process.env.IPFS_CID}]`, 'href', ({ value: url }) => {
+        browser.executeAsync(function (url, done) {
+          fetch(url)
+            .then(res => res.text())
+            .then(done, done)
+        }, [ url ], ({ value: contents }) => {
+          browser.expect(contents.toString('utf8')).to.equal(FILE_CONTENT)
+        })
+      })
+  }
+
   browser.end()
 }