feat: expose standalone download function (#73)

This allows downloading binaries for more than one platform.
We want to use this in ipfs-desktop, to download both amd64 and arm64
binaries required for building universal DMGs.

Exposing download function here allows us to
1. leverage cached downloads, avoid fetching same arch twice
2. confirm download by checkign sha512

src/download.js

@@ -236,13 +236,23 @@ async function link ({ depBin, version }) {
   return localBin
 }
 
+/**
+* @param {object} options
+* @param {string} options.version
+* @param {string} options.platform
+* @param {string} options.arch
+* @param {string} options.installPath
+* @param {string} options.distUrl
+*/
+module.exports.download = download
+
 /**
  * @param {string} [version]
  * @param {string} [platform]
  * @param {string} [arch]
  * @param {string} [installPath]
  */
-module.exports = async (version, platform, arch, installPath) => {
+module.exports.downloadAndUpdateBin = async (version, platform, arch, installPath) => {
   const args = cleanArguments(version, platform, arch, installPath)
 
   return link({

src/go-platform.js

@@ -2,31 +2,30 @@
 
 function getGoOs () {
   switch (process.platform) {
-    case "sunos":
-      return "solaris"
-    case "win32":
-      return "windows"
+    case 'sunos':
+      return 'solaris'
+    case 'win32':
+      return 'windows'
   }
 
   return process.platform
 }
 
 function getGoArch () {
   switch (process.arch) {
-    case "ia32":
-      return "386"
-    case "x64":
-      return "amd64"
-    case "arm":
-      return "arm"
-    case "arm64":
-      return "arm64"
+    case 'ia32':
+      return '386'
+    case 'x64':
+      return 'amd64'
+    case 'arm':
+      return 'arm'
+    case 'arm64':
+      return 'arm64'
   }
 
   return process.arch
 }
 
-
 module.exports = {
   GOOS: getGoOs(),
   GOARCH: getGoArch()

src/index.js

@@ -2,6 +2,9 @@
 
 const fs = require('fs')
 const path = require('path')
+const { download } = require('./download')
+
+module.exports.download = download
 
 module.exports.path = function () {
   if (process.env.KUBO_BINARY) {

src/post-install.js

@@ -1,8 +1,8 @@
 'use strict'
 
-const download = require('./download')
+const { downloadAndUpdateBin } = require('./download')
 
-download()
+downloadAndUpdateBin()
   .catch(err => {
     console.error(err)
     process.exit(1)

test/download.js

@@ -2,14 +2,16 @@
 
 const test = require('tape-promise').default(require('tape'))
 const fs = require('fs-extra')
-const download = require('../src/download')
+const os = require('os')
+const path= require('path')
+const { download, downloadAndUpdateBin } = require('../src/download')
 const { path: detectLocation } = require('../')
 const clean = require('./fixtures/clean')
 
 test('Ensure ipfs gets downloaded (current version and platform)', async (t) => {
   await clean()
 
-  const installPath = await download()
+  const installPath = await downloadAndUpdateBin()
   const stats = await fs.stat(installPath)
 
   t.ok(stats, 'kubo was downloaded')
@@ -21,7 +23,7 @@ test('Ensure ipfs gets downloaded (current version and platform)', async (t) =>
 test('Returns an error when version unsupported', async (t) => {
   await clean()
 
-  await t.rejects(download('bogusversion', 'linux'), /Error: Version 'bogusversion' not available/)
+  await t.rejects(downloadAndUpdateBin('bogusversion', 'linux'), /Error: Version 'bogusversion' not available/)
 
   t.end()
 })
@@ -31,7 +33,7 @@ test('Returns an error when KUBO_DIST_URL is 404', async (t) => {
 
   process.env.KUBO_DIST_URL = 'https://dist.ipfs.tech/notfound'
 
-  await t.rejects(download(), /404/)
+  await t.rejects(downloadAndUpdateBin(), /404/)
 
   delete process.env.KUBO_DIST_URL
 
@@ -43,18 +45,39 @@ test('Returns an error when legacy GO_IPFS_DIST_URL is 404', async (t) => {
 
   process.env.GO_IPFS_DIST_URL = 'https://dist.ipfs.tech/notfound'
 
-  await t.rejects(download(), /404/)
+  await t.rejects(downloadAndUpdateBin(), /404/)
 
   delete process.env.GO_IPFS_DIST_URL
 
   t.end()
 })
 
-
 test('Path returns undefined when no binary has been downloaded', async (t) => {
   await clean()
 
   t.throws(detectLocation, /not found/, 'Path throws if binary is not installed')
 
   t.end()
 })
+
+test('Ensure calling download function manually with static values works', async (t) => {
+  await clean()
+
+  const { version } = require('../package.json')
+  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'temp-dir-'))
+
+  console.log(tempDir)
+  const kuboPath = await download({
+    version: `v${version}`,
+    platform: 'darwin',
+    arch: 'arm64',
+    distUrl: 'https://dist.ipfs.tech',
+    installPath: tempDir,
+  })
+  console.log(kuboPath)
+  const stats = await fs.stat(kuboPath)
+
+  t.ok(stats, 'kubo was downloaded to installPath')
+
+  t.end()
+})