fix: node install script

npm/install.js

@@ -0,0 +1,84 @@
+#!/usr/bin/env node
+
+'use strict';
+
+const request = require('request'),
+  os = require('os'),
+  fs = require('fs'),
+  exec = require('child_process').exec,
+  packageJson = require('./package.json');
+
+// Mapping from Node's `process.arch` to Golang's `$GOARCH`
+const ARCH_MAPPING = {
+  ia32: '386',
+  x64: 'amd64',
+  arm: 'arm',
+  arm64: 'arm64'
+};
+
+// Mapping between Node's `process.platform` to Golang's
+const PLATFORM_MAPPING = {
+  darwin: 'darwin',
+  linux: 'linux',
+  win32: 'windows',
+  freebsd: 'freebsd'
+};
+
+const name = 'safebox';
+const version = packageJson.version;
+const platform = process.platform;
+const arch = process.arch;
+const binaryName = platform === 'win32' ? `${name}.ext` : name;
+const tarUrl = `https://github.com/adikari/safebox/releases/download/v${version}/safebox_${version}_${platform}_${arch}.tar.gz`;
+const nodeModulesBin = './node_modules/.bin';
+
+const error = msg => {
+  console.error(msg);
+  process.exit(1);
+};
+
+if (!(arch in ARCH_MAPPING)) {
+  error(`${name} is not supported for this architecture: ${arch}`);
+  return;
+}
+
+if (!(platform in PLATFORM_MAPPING)) {
+  error(`${name} is not supported for this platform: ${platform}`);
+  return;
+}
+
+const ensureDir = dir => {
+  if (!fs.existsSync(dir)) {
+    fs.mkdirSync(dir);
+  }
+
+  return dir;
+};
+
+const install = () => {
+  const tmpdir = os.tmpdir();
+  const req = request({ uri: tarUrl });
+
+  const tarFile = `${tmpdir}/${name}.tar.gz`;
+  const download = fs.createWriteStream(tarFile);
+
+  req.on('response', res => {
+    if (res.statusCode !== 200) {
+      return callback('Error downloading safebox binary. HTTP Status Code: ' + res.statusCode);
+    }
+
+    req.pipe(download);
+  });
+
+  req.on('complete', () => {
+    exec(`tar -xf ${tarFile} -C ${tmpdir}`, error => {
+      if (error) {
+        error(`error: ${error.message}`);
+      }
+      const dest = ensureDir(nodeModulesBin);
+      fs.copyFileSync(`${tmpdir}/${binaryName}`, `${dest}/${binaryName}`);
+    });
+  });
+};
+
+install();