ADD unit tests, split and refactor source code

__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);
+  });
+});