merges

1-js/4-object-basics/03-object-methods/8-chain-calls/_js.view/solution.js

@@ -0,0 +1,15 @@
+
+let ladder = {
+  step: 0,
+  up: function() { 
+    this.step++;
+    return this;
+  },
+  down: function() { 
+    this.step--;
+    return this;
+  },
+  showStep: function() { 
+    alert(this.step);
+  }
+};

1-js/4-object-basics/03-object-methods/8-chain-calls/_js.view/test.js

@@ -0,0 +1,40 @@
+
+describe('Ladder', function() {
+  before(function() {
+    window.alert = sinon.stub(window, "alert");
+  });
+  
+  beforeEach(function() {
+    ladder.step = 0;
+  });
+
+  it('up() should return this', function() {
+    assert.equal(ladder.up(), ladder);
+  });
+
+  it('down() should return this', function() {
+    assert.equal(ladder.down(), ladder);
+  });
+
+  it('showStep() should call alert', function() {
+    ladder.showStep();
+    assert(alert.called);
+  });
+
+  it('up() should increase step', function() {
+    assert.equal(ladder.up().up().step, 2);
+  });
+
+  it('down() should decrease step', function() {
+    assert.equal(ladder.down().step, -1);
+  });
+
+  it('down().up().up().up() ', function() {
+    assert.equal(ladder.down().up().up().up().step, 2);
+  });
+  
+  after(function() {
+    ladder.step = 0;
+    alert.restore();
+  });
+});