Merge pull request #1 from RecuencoJones/bugfix/add-windows-ext-replace-opt

ADD win_ext to URL template variables

.gitignore

@@ -1,3 +1,4 @@
 .idea
 node_modules
+coverage
 bin

.travis.yml

@@ -0,0 +1,4 @@
+language: node_js
+node_js:
+- "8"
+- "10"

README.md

@@ -1,16 +1,16 @@
 ## Go NPM
 ### Distribute cross-platform Go binaries via NPM
 
-Applications written in Golang are portable - you can easily cross-compile binaries that work on Windows, Mac, and Linux. But how do you distribute the binaries to customers? When you publish new releases, how do they update the binary? 
+Applications written in Golang are portable - you can easily cross-compile binaries that work on Windows, Mac, and Linux. But how do you distribute the binaries to customers? When you publish new releases, how do they update the binary?
 
 **Use NPM to distribute cross-platform Go binaries**
 
 ## Kidding me! Why NPM?
-* **Cross-platform**: NPM is the only popular package manager that works cross-platform. 
-* **Lower barier to entry**: Most developers have NPM installed already. 
+* **Cross-platform**: NPM is the only popular package manager that works cross-platform.
+* **Lower barier to entry**: Most developers have NPM installed already.
 * **Pain free publishing**: It just takes one command to publish - `npm publish`
 * **Dead simple install & update story**: `npm install/update -g your-awesome-app`
-* **Adds $PATH**: NPM will automatically add your binary location to $PATH and generate .cmd file for Windows. Your app just works after installation! 
+* **Adds $PATH**: NPM will automatically add your binary location to $PATH and generate .cmd file for Windows. Your app just works after installation!
 
 ## Okay, tell me how?
 ### 1. Publish your binaries
@@ -76,7 +76,7 @@ You need to tell `go-npm` where to download the binaries from, and where to inst
       "url": "https://github.com/user/my-go-package/releases/download/v{{version}}/myGoPackage_{{version}}_{{platform}}_{{arch}}.tar.gz"
 ```
 
-* *name*: Name of the command users will use to run your binary. 
+* *name*: Name of the command users will use to run your binary.
 * *path*: Temporary path where binaries will be downloaded to
 * *url*: HTTP Web server where binaries are hosted.
 
@@ -84,6 +84,7 @@ Following variables are available to customize the URL:
 * `{{version}}`: Version number read from  `package.json` file. When you publish your package to NPM, it will use this version number. Ex: 0.0.1
 * `{{platform}}`: `$GOOS` value for the platform
 * `{{arch}}`: `$GOARCH` value for the architecture
+* `{{ win_ext }}`: optional `.exe` extension for windows assets.
 
 If you use `goreleaser` to publish your modules, it will automatically set the right architecture & platform in your URL.
 
@@ -106,4 +107,4 @@ To Update:
 
 ---
 
-With ❤️ to the community by [Sanath Kumar Ramesh](http://twitter.com/sanathkr_)
+With ❤️ to the community by [Sanath Kumar Ramesh](http://twitter.com/sanathkr_)

__test__/actions/install.spec.js

@@ -0,0 +1,91 @@
+const { EventEmitter } = require('events');
+const request = require('request');
+const common = require('../../src/common');
+const install = require('../../src/actions/install');
+const move = require('../../src/assets/move');
+const untar = require('../../src/assets/untar');
+const verifyAndPlaceCallback = require('../../src/assets/binary');
+
+jest.mock('fs');
+jest.mock('mkdirp');
+jest.mock('request');
+jest.mock('../../src/common');
+jest.mock('../../src/assets/move');
+jest.mock('../../src/assets/untar');
+jest.mock('../../src/assets/binary');
+
+describe('install()', () => {
+
+  let callback, requestEvents;
+
+  beforeEach(() => {
+
+    callback = jest.fn();
+
+    requestEvents = new EventEmitter();
+  });
+
+  it('should call callback with error if package.json did not return value' , () => {
+    common.parsePackageJson.mockReturnValueOnce(undefined);
+
+    install(callback);
+
+    expect(callback).toHaveBeenCalledWith('Invalid inputs');
+  });
+
+  it('should call callback with error on request error', () => {
+    request.mockReturnValueOnce(requestEvents);
+    common.parsePackageJson.mockReturnValueOnce({ url: 'http://url' });
+
+    install(callback);
+
+    requestEvents.emit('error');
+
+    expect(callback).toHaveBeenCalledWith('Error downloading from URL: http://url');
+  });
+
+  it('should call callback with error on response with status code different than 200', () => {
+    request.mockReturnValueOnce(requestEvents);
+    common.parsePackageJson.mockReturnValueOnce({ url: 'http://url' });
+
+    install(callback);
+
+    requestEvents.emit('response', { statusCode: 404 });
+
+    expect(callback).toHaveBeenCalledWith('Error downloading binary. HTTP Status Code: 404');
+  });
+
+  it('should pick move strategy if url is an uncompressed binary', () => {
+    request.mockReturnValueOnce(requestEvents);
+    common.parsePackageJson.mockReturnValueOnce({ url: 'http://url' });
+
+    install(callback);
+
+    requestEvents.emit('response', { statusCode: 200 });
+
+    expect(move).toHaveBeenCalled();
+  });
+
+  it('should pick untar strategy if url ends with .tar.gz', () => {
+    request.mockReturnValueOnce(requestEvents);
+    common.parsePackageJson.mockReturnValueOnce({ url: 'http://url.tar.gz' });
+
+    install(callback);
+
+    requestEvents.emit('response', { statusCode: 200 });
+
+    expect(untar).toHaveBeenCalled();
+  });
+
+  it('should call verifyAndPlaceCallback on success', () => {
+    request.mockReturnValueOnce(requestEvents);
+    common.parsePackageJson.mockReturnValueOnce({ url: 'http://url', binName: 'command', binPath: './bin' });
+    move.mockImplementationOnce(({ onSuccess }) => onSuccess());
+
+    install(callback);
+
+    requestEvents.emit('response', { statusCode: 200 });
+
+    expect(verifyAndPlaceCallback).toHaveBeenCalledWith('command', './bin', callback);
+  });
+});

__test__/actions/uninstall.spec.js

@@ -0,0 +1,59 @@
+const fs = require('fs');
+const common = require('../../src/common');
+const uninstall = require('../../src/actions/uninstall');
+
+jest.mock('fs');
+jest.mock('../../src/common');
+
+describe('uninstall()', () => {
+
+  let callback;
+
+  beforeEach(() => {
+
+    callback = jest.fn();
+
+    common.parsePackageJson.mockReturnValueOnce({ binName: 'command' });
+  });
+
+  it('should call callback with error if binary not found', () => {
+    const error = new Error();
+
+    common.getInstallationPath.mockImplementationOnce((cb) => cb(error));
+
+    uninstall(callback);
+
+    expect(callback).toHaveBeenCalledWith(error);
+  });
+
+  it('should call unlinkSync with binary and installation path', () => {
+
+    common.getInstallationPath.mockImplementationOnce((cb) => cb(null, './bin'));
+
+    uninstall(callback);
+
+    expect(fs.unlinkSync).toHaveBeenCalledWith('bin/command');
+  });
+
+  it('should call callback on success', () => {
+
+    common.getInstallationPath.mockImplementationOnce((cb) => cb(null, './bin'));
+
+    uninstall(callback);
+
+    expect(callback).toHaveBeenCalledWith(null);
+  });
+
+  it('should call callback regardless of errors on unlink', () => {
+
+    common.getInstallationPath.mockImplementationOnce((cb) => cb(null, './bin'));
+
+    fs.unlinkSync.mockImplementationOnce(() => {
+      throw new Error();
+    });
+
+    uninstall(callback);
+
+    expect(callback).toHaveBeenCalledWith(null);
+  });
+});

__test__/assets/binary.spec.js

@@ -0,0 +1,51 @@
+const fs = require('fs');
+const common = require('../../src/common');
+const verifyAndPlaceBinary = require('../../src/assets/binary');
+
+jest.mock('fs');
+jest.mock('../../src/common');
+
+describe('verifyAndPlaceBinary()', () => {
+  let callback;
+
+  beforeEach(() => {
+    callback = jest.fn();
+  });
+
+  it('should call callback with error if binary downloaded differs from config', () => {
+    fs.existsSync.mockReturnValueOnce(false);
+
+    verifyAndPlaceBinary('command', './bin', callback);
+
+    expect(callback).toHaveBeenCalledWith('Downloaded binary does not contain the binary specified in configuration - command');
+  });
+
+  it('should call callback with error if installation path cannot be found', () => {
+    const error = new Error();
+
+    fs.existsSync.mockReturnValueOnce(true);
+    common.getInstallationPath.mockImplementationOnce((cb) => cb(error));
+
+    verifyAndPlaceBinary('command', './bin', callback);
+
+    expect(callback).toHaveBeenCalledWith(error);
+  });
+
+  it('should call callback with null on success', () => {
+    fs.existsSync.mockReturnValueOnce(true);
+    common.getInstallationPath.mockImplementationOnce((cb) => cb(null, '/usr/local/bin'));
+
+    verifyAndPlaceBinary('command', './bin', callback);
+
+    expect(callback).toHaveBeenCalledWith(null);
+  });
+
+  it('should move the binary to installation directory', () => {
+    fs.existsSync.mockReturnValueOnce(true);
+    common.getInstallationPath.mockImplementationOnce((cb) => cb(null, '/usr/local/bin'));
+
+    verifyAndPlaceBinary('command', './bin', callback);
+
+    expect(fs.renameSync).toHaveBeenCalledWith('bin/command', '/usr/local/bin/command');
+  });
+});

__test__/assets/move.spec.js

@@ -0,0 +1,49 @@
+const { EventEmitter } = require('events');
+const fs = require('fs');
+const move = require('../../src/assets/move');
+
+jest.mock('fs');
+
+describe('move()', () => {
+
+  let streamEvents, pipe, onSuccess, onError;
+
+  beforeEach(() => {
+
+    streamEvents = new EventEmitter();
+
+    pipe = jest.fn();
+    onSuccess = jest.fn();
+    onError = jest.fn();
+    createWriteStream = jest.fn();
+
+    fs.createWriteStream.mockReturnValueOnce(streamEvents);
+  });
+
+  it('should download resource to given binPath', () => {
+
+    move({ opts: { binPath: './bin', binName: 'command' }, req: { pipe }, onSuccess, onError });
+
+    expect(fs.createWriteStream).toHaveBeenCalledWith('bin/command');
+  });
+
+  it('should call onSuccess on stream closed', () => {
+
+    move({ opts: { binPath: './bin', binName: 'command' }, req: { pipe }, onSuccess, onError });
+
+    streamEvents.emit('close');
+
+    expect(onSuccess).toHaveBeenCalled();
+  });
+
+  it('should call onError with error on write stream error', () => {
+
+    const error = new Error();
+
+    move({ opts: { binPath: './bin', binName: 'command' }, req: { pipe }, onSuccess, onError });
+
+    streamEvents.emit('error', error);
+
+    expect(onError).toHaveBeenCalledWith(error);
+  });
+});

__test__/assets/untar.spec.js

@@ -0,0 +1,65 @@
+const { EventEmitter } = require('events');
+const zlib = require('zlib');
+const tar = require('tar');
+const untar = require('../../src/assets/untar');
+
+jest.mock('zlib');
+jest.mock('tar', () => ({
+  Extract: jest.fn()
+}));
+
+describe('untar()', () => {
+
+  let ungzEvents, untarEvents, pipe, onSuccess, onError;
+
+  beforeEach(() => {
+    ungzEvents = new EventEmitter();
+    untarEvents = new EventEmitter();
+
+    pipe = jest.fn();
+    onSuccess = jest.fn();
+    onError = jest.fn();
+
+    pipe.mockReturnValueOnce({ pipe });
+    tar.Extract.mockReturnValueOnce(untarEvents);
+    zlib.createGunzip.mockReturnValueOnce(ungzEvents);
+  });
+
+  it('should download resource and untar to given binPath', () => {
+
+    untar({ opts: { binPath: './bin', binName: 'command' }, req: { pipe }, onSuccess, onError });
+
+    expect(tar.Extract).toHaveBeenCalledWith({ path: './bin' });
+  });
+
+  it('should call onSuccess on untar end', () => {
+
+    untar({ opts: { binPath: './bin', binName: 'command' }, req: { pipe }, onSuccess, onError });
+
+    untarEvents.emit('end');
+
+    expect(onSuccess).toHaveBeenCalled();
+  });
+
+  it('should call onError with error on ungz error', () => {
+
+    const error = new Error();
+
+    untar({ opts: { binPath: './bin', binName: 'command' }, req: { pipe }, onSuccess, onError });
+
+    ungzEvents.emit('error', error);
+
+    expect(onError).toHaveBeenCalledWith(error);
+  });
+
+  it('should call onError with error on untar error', () => {
+
+    const error = new Error();
+
+    untar({ opts: { binPath: './bin', binName: 'command' }, req: { pipe }, onSuccess, onError });
+
+    untarEvents.emit('error', error);
+
+    expect(onError).toHaveBeenCalledWith(error);
+  });
+});

__test__/cli.spec.js

@@ -0,0 +1,40 @@
+const cli = require('../src/cli');
+const install = require('../src/actions/install');
+
+jest.mock('../src/actions/install');
+
+describe('cli()', () => {
+  let exit;
+
+  beforeEach(() => {
+    exit = jest.fn();
+  });
+
+  it('should exit with error if not enough args are supplied', () => {
+    cli({ argv: [], exit });
+
+    expect(exit).toHaveBeenCalledWith(1);
+  });
+
+  it('should exit with error if command does not exist', () => {
+    cli({ argv: [ '/usr/local/bin/node', 'index.js', 'command' ], exit });
+
+    expect(exit).toHaveBeenCalledWith(1);
+  });
+
+  it('should exit with error if command returns error', () => {
+    install.mockImplementationOnce((cb) => cb(new Error()));
+
+    cli({ argv: [ '/usr/local/bin/node', 'index.js', 'install' ], exit });
+
+    expect(exit).toHaveBeenCalledWith(1);
+  });
+
+  it('should exit with success if command runs fine', () => {
+    install.mockImplementationOnce((cb) => cb(null));
+
+    cli({ argv: [ '/usr/local/bin/node', 'index.js', 'install' ], exit });
+
+    expect(exit).toHaveBeenCalledWith(0);
+  });
+});

__test__/common.spec.js

@@ -0,0 +1,123 @@
+const fs = require('fs');
+const childProcess = require('child_process');
+const common = require('../src/common');
+
+jest.mock('fs');
+jest.mock('child_process');
+jest.mock('mkdirp');
+
+describe('common', () => {
+  describe('getInstallationPath()', () => {
+    let callback, env;
+
+    beforeEach(() => {
+      callback = jest.fn();
+
+      env = { ...process.env };
+    });
+
+    afterEach(() => {
+      process.env = env;
+    });
+
+    it('should get binaries path from `npm bin`', () => {
+      childProcess.exec.mockImplementationOnce((_cmd, cb) => cb(null, '/usr/local/bin'));
+
+      common.getInstallationPath(callback);
+
+      expect(callback).toHaveBeenCalledWith(null, '/usr/local/bin');
+    });
+
+    it('should get binaries path from env', () => {
+      childProcess.exec.mockImplementationOnce((_cmd, cb) => cb(new Error()));
+
+      process.env.npm_config_prefix = '/usr/local';
+
+      common.getInstallationPath(callback);
+
+      expect(callback).toHaveBeenCalledWith(null, '/usr/local/bin');
+    });
+
+    it('should call callback with error if binaries path is not found', () => {
+      childProcess.exec.mockImplementationOnce((_cmd, cb) => cb(new Error()));
+
+      process.env.npm_config_prefix = undefined;
+
+      common.getInstallationPath(callback);
+
+      expect(callback).toHaveBeenCalledWith(new Error('Error finding binary installation directory'));
+    });
+  });
+
+  describe('parsePackageJson()', () => {
+    let _process;
+
+    beforeEach(() => {
+      _process = { ...global.process };
+    });
+
+    afterEach(() => {
+      global.process = _process;
+    });
+
+    describe('validation', () => {
+      it('should return if architecture is unsupported', () => {
+        process.arch = 'mips';
+
+        expect(common.parsePackageJson()).toBeUndefined();
+      });
+
+      it('should return if platform is unsupported', () => {
+        process.platform = 'amiga';
+
+        expect(common.parsePackageJson()).toBeUndefined();
+      });
+
+      it('should return if package.json does not exist', () => {
+        fs.existsSync.mockReturnValueOnce(false);
+
+        expect(common.parsePackageJson()).toBeUndefined();
+      });
+    });
+
+    describe('variable replacement', () => {
+      it('should append .exe extension on windows platform', () => {
+        fs.existsSync.mockReturnValueOnce(true);
+        fs.readFileSync.mockReturnValueOnce(JSON.stringify({
+          version: '1.0.0',
+          goBinary: {
+            name: 'command',
+            path: './bin',
+            url: 'https://github.com/foo/bar/releases/v{{version}}/assets/command{{win_ext}}'
+          }
+        }));
+
+        process.platform = 'win32';
+
+        expect(common.parsePackageJson()).toMatchObject({
+          binName: 'command.exe',
+          url: 'https://github.com/foo/bar/releases/v1.0.0/assets/command.exe'
+        });
+      });
+
+      it('should not append .exe extension on platform different than windows', () => {
+        fs.existsSync.mockReturnValueOnce(true);
+        fs.readFileSync.mockReturnValueOnce(JSON.stringify({
+          version: '1.0.0',
+          goBinary: {
+            name: 'command',
+            path: './bin',
+            url: 'https://github.com/foo/bar/releases/v{{version}}/assets/command{{win_ext}}'
+          }
+        }));
+
+        process.platform = 'darwin';
+
+        expect(common.parsePackageJson()).toMatchObject({
+          binName: 'command',
+          url: 'https://github.com/foo/bar/releases/v1.0.0/assets/command'
+        });
+      });
+    });
+  });
+});

__test__/index.spec.js

@@ -1,127 +0,0 @@
-const rewire = require('rewire');
-const EventEmitter = require('events').EventEmitter;
-
-describe('go-npm', function() {
-    let mod;
-
-    beforeEach(function() {
-        mod = rewire('../src/index.js');
-    });
-
-    describe('Resource handling strategies', function() {
-
-        describe('untarStrategy()', function() {
-
-            let untarStrategy, ungzEvents, untarEvents, pipe, callback, zlib, createGunzip, tar;
-
-            beforeEach(function() {
-                untarStrategy = mod.__get__('untarStrategy');
-                zlib = mod.__get__('zlib');
-                tar = mod.__get__('tar');
-                ungzEvents = new EventEmitter();
-                untarEvents = new EventEmitter();
-
-                createGunzip = jest.fn();
-                pipe = jest.fn();
-                callback = jest.fn();
-
-                pipe.mockReturnValueOnce({ pipe });
-                createGunzip.mockReturnValueOnce(ungzEvents);
-                jest.spyOn(tar, 'Extract').mockReturnValueOnce(untarEvents);
-
-                // jest.spyOn not working on read-only properties
-                Object.defineProperty(zlib, 'createGunzip', { value: createGunzip });
-            });
-
-            it('should download resource and untar to given binPath', function() {
-
-                untarStrategy({ binPath: './bin', binName: 'command' }, { pipe }, callback);
-
-                expect(tar.Extract).toHaveBeenCalledWith({ path: './bin' });
-            });
-
-            it('should call verifyAndPlaceBinary on untar end', function() {
-
-                const verifyAndPlaceBinary = jest.fn();
-
-                mod.__set__('verifyAndPlaceBinary', verifyAndPlaceBinary);
-
-                untarStrategy({ binPath: './bin', binName: 'command' }, { pipe }, callback);
-
-                untarEvents.emit('end');
-
-                expect(verifyAndPlaceBinary).toHaveBeenCalledWith('command', './bin', callback);
-            });
-
-            it('should call callback with error on ungz error', function() {
-
-                const error = new Error();
-
-                untarStrategy({ binPath: './bin', binName: 'command' }, { pipe }, callback);
-
-                ungzEvents.emit('error', error);
-
-                expect(callback).toHaveBeenCalledWith(error);
-            });
-
-            it('should call callback with error on untar error', function() {
-
-                const error = new Error();
-
-                untarStrategy({ binPath: './bin', binName: 'command' }, { pipe }, callback);
-
-                untarEvents.emit('error', error);
-
-                expect(callback).toHaveBeenCalledWith(error);
-            });
-        });
-
-        describe('moveStrategy()', function() {
-
-            let moveStrategy, streamEvents, pipe, callback, fs;
-
-            beforeEach(function() {
-
-                moveStrategy = mod.__get__('moveStrategy');
-                fs = mod.__get__('fs');
-                streamEvents = new EventEmitter();
-
-                pipe = jest.fn();
-                callback = jest.fn();
-
-                jest.spyOn(fs, 'createWriteStream').mockReturnValueOnce(streamEvents);
-            });
-
-            it('should download resource to given binPath', function() {
-
-                moveStrategy({ binPath: './bin', binName: 'command' }, { pipe }, callback);
-
-                expect(fs.createWriteStream).toHaveBeenCalledWith('bin/command');
-            });
-
-            it('should call verifyAndPlaceBinary on stream closed', function() {
-
-                const verifyAndPlaceBinary = jest.fn();
-
-                mod.__set__('verifyAndPlaceBinary', verifyAndPlaceBinary);
-
-                moveStrategy({ binPath: './bin', binName: 'command' }, { pipe }, callback);
-
-                streamEvents.emit('close');
-
-                expect(verifyAndPlaceBinary).toHaveBeenCalledWith('command', './bin', callback);
-            });
-
-            it('should call callback with error on write stream error', function() {
-
-                const error = new Error();
-
-                moveStrategy({ binPath: './bin', binName: 'command' }, { pipe }, callback);
-
-                streamEvents.emit('error', error);
-
-                expect(callback).toHaveBeenCalledWith(error);
-            });
-        });
-    });
-});

package.json

@@ -26,7 +26,6 @@
     "babel-cli": "^6.24.1",
     "babel-core": "^6.25.0",
     "babel-preset-es2015": "^6.24.1",
-    "jest": "^24.5.0",
-    "rewire": "^4.0.1"
+    "jest": "^24.5.0"
   }
 }

src/actions/install.js

@@ -0,0 +1,52 @@
+const mkdirp = require('mkdirp');
+const request = require('request');
+const { parsePackageJson } = require('../common');
+const verifyAndPlaceBinary = require('../assets/binary');
+
+/**
+ * Select a resource handling strategy based on given options.
+ */
+function getStrategy({ url }) {
+
+  if (url.endsWith('.tar.gz')) {
+      return require('../assets/untar');
+  } else {
+      return require('../assets/move');
+  }
+}
+
+/**
+ * Reads the configuration from application's package.json,
+ * validates properties, downloads the binary, untars, and stores at
+ * ./bin in the package's root. NPM already has support to install binary files
+ * specific locations when invoked with "npm install -g"
+ *
+ *  See: https://docs.npmjs.com/files/package.json#bin
+ */
+function install(callback) {
+
+  const opts = parsePackageJson();
+  if (!opts) return callback('Invalid inputs');
+
+  mkdirp.sync(opts.binPath);
+
+  console.log('Downloading from URL: ' + opts.url);
+
+  const req = request({ uri: opts.url });
+
+  req.on('error', () => callback('Error downloading from URL: ' + opts.url));
+  req.on('response', (res) => {
+      if (res.statusCode !== 200) return callback('Error downloading binary. HTTP Status Code: ' + res.statusCode);
+
+      const strategy = getStrategy(opts);
+
+      strategy({
+          opts,
+          req,
+          onSuccess: () => verifyAndPlaceBinary(opts.binName, opts.binPath, callback),
+          onError: callback
+      });
+  });
+}
+
+module.exports = install;

src/actions/uninstall.js

@@ -0,0 +1,24 @@
+const { join } = require('path');
+const { unlinkSync } = require('fs');
+const { parsePackageJson, getInstallationPath } = require('../common');
+
+function uninstall(callback) {
+
+  const { binName } = parsePackageJson();
+
+  getInstallationPath((err, installationPath) => {
+      if (err) {
+          return callback(err);
+      }
+
+      try {
+          unlinkSync(join(installationPath, binName));
+      } catch(ex) {
+          // Ignore errors when deleting the file.
+      }
+
+      return callback(null);
+  });
+}
+
+module.exports = uninstall;

src/assets/binary.js

@@ -0,0 +1,25 @@
+const { join } = require('path');
+const { existsSync, renameSync, chmodSync } = require('fs');
+const { getInstallationPath } = require('../common');
+
+function verifyAndPlaceBinary(binName, binPath, callback) {
+  if (!existsSync(join(binPath, binName))) {
+    return callback(`Downloaded binary does not contain the binary specified in configuration - ${binName}`);
+  }
+
+  getInstallationPath((err, installationPath) => {
+      if (err) {
+        return callback(err);
+      }
+
+      // Move the binary file and make sure it is executable
+      renameSync(join(binPath, binName), join(installationPath, binName));
+      chmodSync(join(installationPath, binName), '755');
+
+      console.log('Placed binary on', join(installationPath, binName));
+
+      callback(null);
+  });
+}
+
+module.exports = verifyAndPlaceBinary;

src/assets/move.js

@@ -0,0 +1,17 @@
+const { join } = require('path');
+const { createWriteStream } = require('fs');
+
+/**
+ * Move strategy for binary resources without compression.
+ */
+function move({ opts, req, onSuccess, onError }) {
+
+  const stream = createWriteStream(join(opts.binPath, opts.binName));
+
+  stream.on('error', onError);
+  stream.on('close', onSuccess);
+
+  req.pipe(stream);
+}
+
+module.exports = move;

src/assets/untar.js

@@ -0,0 +1,25 @@
+const tar = require('tar');
+const zlib = require('zlib');
+
+/**
+ * Unzip strategy for resources using `.tar.gz`.
+ *
+ * First we will Un-GZip, then we will untar. So once untar is completed,
+ * binary is downloaded into `binPath`. Verify the binary and call it good.
+ */
+function untar({ opts, req, onSuccess, onError }) {
+
+  const ungz = zlib.createGunzip();
+  const untar = tar.Extract({ path: opts.binPath });
+
+  ungz.on('error', onError);
+  untar.on('error', onError);
+
+  // First we will Un-GZip, then we will untar. So once untar is completed,
+  // binary is downloaded into `binPath`. Verify the binary and call it good
+  untar.on('end', onSuccess);
+
+  req.pipe(ungz).pipe(untar);
+}
+
+module.exports = untar;

src/cli.js

@@ -0,0 +1,28 @@
+const actions = {
+  install: (callback) => require('./actions/install')(callback),
+  uninstall: (callback) => require('./actions/uninstall')(callback)
+};
+
+// Parse command line arguments and call the right action
+module.exports = ({ argv, exit }) => {
+  if (argv && argv.length > 2) {
+    const cmd = argv[2];
+
+    if (!actions[cmd]) {
+      console.log('Invalid command to go-npm. `install` and `uninstall` are the only supported commands');
+      exit(1);
+    } else {
+      actions[cmd]((err) => {
+        if (err) {
+          console.error(err);
+          exit(1);
+        } else {
+          exit(0);
+        }
+      });
+    }
+  } else {
+    console.log('No command supplied. `install` and `uninstall` are the only supported commands');
+    exit(1);
+  }
+};

src/common.js

@@ -0,0 +1,130 @@
+const { join } = require('path');
+const { exec } = require('child_process');
+const { existsSync, readFileSync } = require('fs');
+const mkdirp = require('mkdirp');
+
+// Mapping from Node's `process.arch` to Golang's `$GOARCH`
+const ARCH_MAPPING = {
+  ia32: '386',
+  x64: 'amd64',
+  arm: 'arm'
+};
+
+// Mapping between Node's `process.platform` to Golang's
+const PLATFORM_MAPPING = {
+  darwin: 'darwin',
+  linux: 'linux',
+  win32: 'windows',
+  freebsd: 'freebsd'
+};
+
+function getInstallationPath(callback) {
+
+  // `npm bin` will output the path where binary files should be installed
+  exec('npm bin', (err, stdout, stderr) => {
+
+    let dir = null;
+    if (err || stderr || !stdout || stdout.length === 0) {
+
+      // We couldn't infer path from `npm bin`. Let's try to get it from
+      // Environment variables set by NPM when it runs.
+      // npm_config_prefix points to NPM's installation directory where `bin` folder is available
+      // Ex: /Users/foo/.nvm/versions/node/v4.3.0
+      const env = process.env;
+
+      if (env && env.npm_config_prefix) {
+        dir = join(env.npm_config_prefix, 'bin');
+      } else {
+        return callback(new Error('Error finding binary installation directory'));
+      }
+    } else {
+      dir = stdout.trim();
+    }
+
+    mkdirp.sync(dir);
+
+    callback(null, dir);
+  });
+}
+
+function validateConfiguration({ version, goBinary }) {
+
+  if (!version) {
+    return "'version' property must be specified";
+  }
+
+  if (!goBinary || typeof (goBinary) !== 'object') {
+    return "'goBinary' property must be defined and be an object";
+  }
+
+  if (!goBinary.name) {
+    return "'name' property is necessary";
+  }
+
+  if (!goBinary.path) {
+    return "'path' property is necessary";
+  }
+
+  if (!goBinary.url) {
+    return "'url' property is required";
+  }
+}
+
+function parsePackageJson() {
+  if (!(process.arch in ARCH_MAPPING)) {
+    console.error('Installation is not supported for this architecture: ' + process.arch);
+    return;
+  }
+
+  if (!(process.platform in PLATFORM_MAPPING)) {
+    console.error('Installation is not supported for this platform: ' + process.platform);
+    return
+  }
+
+  const packageJsonPath = join('.', 'package.json');
+  if (!existsSync(packageJsonPath)) {
+    console.error('Unable to find package.json. ' +
+      'Please run this script at root of the package you want to be installed');
+    return
+  }
+
+  const packageJson = JSON.parse(readFileSync(packageJsonPath));
+  const error = validateConfiguration(packageJson);
+
+  if (error && error.length > 0) {
+    console.error('Invalid package.json: ' + error);
+    return
+  }
+
+  // We have validated the config. It exists in all its glory
+  const binPath = packageJson.goBinary.path;
+  let binName = packageJson.goBinary.name;
+  let url = packageJson.goBinary.url;
+  let version = packageJson.version;
+
+  if (version[0] === 'v') version = version.substr(1);  // strip the 'v' if necessary v0.0.1 => 0.0.1
+
+  // Binary name on Windows has .exe suffix
+  if (process.platform === 'win32') {
+    binName += '.exe'
+
+    url = url.replace(/{{win_ext}}/g, '.exe');
+  } else {
+    url = url.replace(/{{win_ext}}/g, '');
+  }
+
+  // Interpolate variables in URL, if necessary
+  url = url.replace(/{{arch}}/g, ARCH_MAPPING[process.arch]);
+  url = url.replace(/{{platform}}/g, PLATFORM_MAPPING[process.platform]);
+  url = url.replace(/{{version}}/g, version);
+  url = url.replace(/{{bin_name}}/g, binName);
+
+  return {
+    binName,
+    binPath,
+    url,
+    version
+  };
+}
+
+module.exports = { parsePackageJson, getInstallationPath };

src/index.js

@@ -1,261 +1,3 @@
 #!/usr/bin/env node
 
-"use strict"
-
-const request = require('request'),
-    path = require('path'),
-    tar = require('tar'),
-    zlib = require('zlib'),
-    mkdirp = require('mkdirp'),
-    fs = require('fs'),
-    exec = require('child_process').exec;
-
-// Mapping from Node's `process.arch` to Golang's `$GOARCH`
-const ARCH_MAPPING = {
-    "ia32": "386",
-    "x64": "amd64",
-    "arm": "arm"
-};
-
-// Mapping between Node's `process.platform` to Golang's
-const PLATFORM_MAPPING = {
-    "darwin": "darwin",
-    "linux": "linux",
-    "win32": "windows",
-    "freebsd": "freebsd"
-};
-
-function getInstallationPath(callback) {
-
-    // `npm bin` will output the path where binary files should be installed
-    exec("npm bin", function(err, stdout, stderr) {
-
-        let dir =  null;
-        if (err || stderr || !stdout || stdout.length === 0)  {
-
-            // We couldn't infer path from `npm bin`. Let's try to get it from
-            // Environment variables set by NPM when it runs.
-            // npm_config_prefix points to NPM's installation directory where `bin` folder is available
-            // Ex: /Users/foo/.nvm/versions/node/v4.3.0
-            let env = process.env;
-            if (env && env.npm_config_prefix) {
-                dir = path.join(env.npm_config_prefix, "bin");
-            }
-        } else {
-            dir = stdout.trim();
-        }
-
-        mkdirp.sync(dir);
-
-        callback(null, dir);
-    });
-
-}
-
-function verifyAndPlaceBinary(binName, binPath, callback) {
-    if (!fs.existsSync(path.join(binPath, binName))) return callback(`Downloaded binary does not contain the binary specified in configuration - ${binName}`);
-
-    getInstallationPath(function(err, installationPath) {
-        if (err) return callback("Error getting binary installation path from `npm bin`");
-
-        // Move the binary file and make sure it is executable
-        fs.renameSync(path.join(binPath, binName), path.join(installationPath, binName));
-        fs.chmodSync(path.join(installationPath, binName), "755");
-
-        console.log("Placed binary on", path.join(installationPath, binName));
-
-        callback(null);
-    });
-}
-
-function validateConfiguration(packageJson) {
-
-    if (!packageJson.version) {
-        return "'version' property must be specified";
-    }
-
-    if (!packageJson.goBinary || typeof(packageJson.goBinary) !== "object") {
-        return "'goBinary' property must be defined and be an object";
-    }
-
-    if (!packageJson.goBinary.name) {
-        return "'name' property is necessary";
-    }
-
-    if (!packageJson.goBinary.path) {
-        return "'path' property is necessary";
-    }
-
-    if (!packageJson.goBinary.url) {
-        return "'url' property is required";
-    }
-
-    // if (!packageJson.bin || typeof(packageJson.bin) !== "object") {
-    //     return "'bin' property of package.json must be defined and be an object";
-    // }
-}
-
-function parsePackageJson() {
-    if (!(process.arch in ARCH_MAPPING)) {
-        console.error("Installation is not supported for this architecture: " + process.arch);
-        return;
-    }
-
-    if (!(process.platform in PLATFORM_MAPPING)) {
-        console.error("Installation is not supported for this platform: " + process.platform);
-        return
-    }
-
-    const packageJsonPath = path.join(".", "package.json");
-    if (!fs.existsSync(packageJsonPath)) {
-        console.error("Unable to find package.json. " +
-            "Please run this script at root of the package you want to be installed");
-        return
-    }
-
-    let packageJson = JSON.parse(fs.readFileSync(packageJsonPath));
-    let error = validateConfiguration(packageJson);
-    if (error && error.length > 0) {
-        console.error("Invalid package.json: " + error);
-        return
-    }
-
-    // We have validated the config. It exists in all its glory
-    let binName = packageJson.goBinary.name;
-    let binPath = packageJson.goBinary.path;
-    let url = packageJson.goBinary.url;
-    let version = packageJson.version;
-    if (version[0] === 'v') version = version.substr(1);  // strip the 'v' if necessary v0.0.1 => 0.0.1
-
-    // Binary name on Windows has .exe suffix
-    if (process.platform === "win32") {
-        binName += ".exe"
-    }
-
-    // Interpolate variables in URL, if necessary
-    url = url.replace(/{{arch}}/g, ARCH_MAPPING[process.arch]);
-    url = url.replace(/{{platform}}/g, PLATFORM_MAPPING[process.platform]);
-    url = url.replace(/{{version}}/g, version);
-    url = url.replace(/{{bin_name}}/g, binName);
-
-    return {
-        binName: binName,
-        binPath: binPath,
-        url: url,
-        version: version
-    }
-}
-
-/**
- * Unzip strategy for resources using `.tar.gz`.
- *
- * First we will Un-GZip, then we will untar. So once untar is completed,
- * binary is downloaded into `binPath`. Verify the binary and call it good.
- */
-function untarStrategy(opts, req, callback) {
-
-    const ungz = zlib.createGunzip();
-    const untar = tar.Extract({path: opts.binPath});
-
-    ungz.on('error', callback);
-    untar.on('error', callback);
-
-    // First we will Un-GZip, then we will untar. So once untar is completed,
-    // binary is downloaded into `binPath`. Verify the binary and call it good
-    untar.on('end', verifyAndPlaceBinary.bind(null, opts.binName, opts.binPath, callback));
-
-    req.pipe(ungz).pipe(untar);
-}
-
-/**
- * Move strategy for binary resources without compression.
- */
-function moveStrategy(opts, req, callback) {
-
-    const stream = fs.createWriteStream(path.join(opts.binPath, opts.binName));
-
-    stream.on('error', callback);
-    stream.on('close', verifyAndPlaceBinary.bind(null, opts.binName, opts.binPath, callback));
-
-    req.pipe(stream);
-}
-
-/**
- * Select a resource handling strategy based on given options.
- */
-function getStrategy(opts) {
-
-    if (opts.url.endsWith('.tar.gz')) {
-        return untarStrategy;
-    } else {
-        return moveStrategy;
-    }
-}
-
-/**
- * Reads the configuration from application's package.json,
- * validates properties, downloads the binary, untars, and stores at
- * ./bin in the package's root. NPM already has support to install binary files
- * specific locations when invoked with "npm install -g"
- *
- *  See: https://docs.npmjs.com/files/package.json#bin
- */
-const INVALID_INPUT = "Invalid inputs";
-function install(callback) {
-
-    const opts = parsePackageJson();
-    if (!opts) return callback(INVALID_INPUT);
-
-    const strategy = getStrategy(opts);
-    mkdirp.sync(opts.binPath);
-
-    console.log("Downloading from URL: " + opts.url);
-    let req = request({uri: opts.url});
-    req.on('error', callback.bind(null, "Error downloading from URL: " + opts.url));
-    req.on('response', function(res) {
-        if (res.statusCode !== 200) return callback("Error downloading binary. HTTP Status Code: " + res.statusCode);
-
-        strategy(opts, req, callback);
-    });
-}
-
-function uninstall(callback) {
-
-    let opts = parsePackageJson();
-    getInstallationPath(function(err, installationPath) {
-        if (err) callback("Error finding binary installation directory");
-
-        try {
-            fs.unlinkSync(path.join(installationPath, opts.binName));
-        } catch(ex) {
-            // Ignore errors when deleting the file.
-        }
-
-        return callback(null);
-    });
-}
-
-
-// Parse command line arguments and call the right method
-let actions = {
-    "install": install,
-    "uninstall": uninstall
-};
-
-let argv = process.argv;
-if (argv && argv.length > 2) {
-    let cmd = process.argv[2];
-    if (!actions[cmd]) {
-        console.log("Invalid command to go-npm. `install` and `uninstall` are the only supported commands");
-        process.exit(1);
-    }
-
-    actions[cmd](function(err) {
-        if (err) {
-            console.error(err);
-            process.exit(1);
-        } else {
-            process.exit(0);
-        }
-    });
-}
+require('./cli')(process);