ADD unit tests, split and refactor source code

__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);
+  });
+});