ADD unit testing for resource strategies

.npmignore

@@ -1,3 +1,4 @@
 .idea
 node_modules
 src
+__test__

__test__/index.spec.js

@@ -0,0 +1,127 @@
+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

@@ -7,7 +7,7 @@
     "go-npm": "./bin/index.js"
   },
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1",
+    "test": "jest",
     "prepublish": "node_modules/babel-cli/bin/babel.js src --out-dir bin --presets es2015"
   },
   "author": "Sanath Kumar Ramesh <dayanandasaraswati@gmail.com>",
@@ -25,6 +25,8 @@
   "devDependencies": {
     "babel-cli": "^6.24.1",
     "babel-core": "^6.25.0",
-    "babel-preset-es2015": "^6.24.1"
+    "babel-preset-es2015": "^6.24.1",
+    "jest": "^24.5.0",
+    "rewire": "^4.0.1"
   }
 }