battle component tests

Author: krawaller

src/specs/component.battle.spec.ts

@@ -0,0 +1,113 @@
+/******************************************
+Unit tests for the Battle component. We need to test...
+
+ * template
+ * correct appliance of the `winner` class depending on `Combatant` outputs
+
+/*******************************************/
+
+// --------------- Child component stubs -----------------
+
+import { Component, Output, EventEmitter } from '@angular/core';
+
+@Component({
+  selector: 'combatant',
+  template: ''
+})
+class FakeCombatant {
+  @Output() stars = new EventEmitter<number>()
+}
+
+// --------------- Test config ---------------
+
+import { CommonModule } from '@angular/common';
+
+import { BattleComponent } from '../components/battle';
+
+const testModuleConfig = {
+  imports: [CommonModule],
+  declarations: [BattleComponent, FakeCombatant]
+}
+
+// --------------- Test suite ---------------
+
+import { TestBed, getTestBed, ComponentFixture } from '@angular/core/testing';
+import { By } from '@angular/platform-browser';
+import { expect } from 'chai';
+import { DebugElement } from '@angular/core';
+
+let fixture: ComponentFixture<BattleComponent>
+let instance: BattleComponent
+let debugElement: DebugElement
+let nativeElement: HTMLElement;
+
+describe('BattleComponent', () => {
+  before(() => TestBed.configureTestingModule(testModuleConfig));
+  after(() => getTestBed().resetTestingModule());
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(BattleComponent);
+    debugElement = fixture.debugElement;
+    instance = debugElement.componentInstance;
+    nativeElement = debugElement.nativeElement;
+    fixture.detectChanges();
+  });
+
+  it('should instantiate ok', () => {
+    expect(instance).to.exist;
+  });
+
+  it('should render two combatants', () => {
+    expect(nativeElement.querySelectorAll('combatant').length).to.equal(2);
+  });
+
+  describe('the winner class', () => {
+    let combatant1: FakeCombatant, combatant2: FakeCombatant, combatantElement1: HTMLElement, combatantElement2: HTMLElement;
+    beforeEach(() => {
+      [combatant1, combatant2] = debugElement.queryAll(By.css('combatant')).map(el => el.componentInstance);
+      [combatantElement1, combatantElement2] = Array.from(nativeElement.querySelectorAll('combatant'));
+    });
+    it('should not be initially applied', () => {
+      expect(nativeElement.querySelector('.winner')).to.not.exist;
+    });
+    it('should not be applied after we have just one count', () => {
+      combatant1.stars.emit(456);
+      expect(nativeElement.querySelector('.winner')).to.not.exist;
+    });
+    it('should be applied to combatant1 when count exceeds combatant2', () => {
+      combatant1.stars.emit(5);
+      combatant2.stars.emit(4);
+      fixture.detectChanges();
+      expect(combatantElement1.classList.contains('winner')).to.be.true;
+      expect(combatantElement2.classList.contains('winner')).to.be.false;
+    });
+    it('should be applied to combatant2 when count exceeds combatant1', () => {
+      combatant1.stars.emit(1);
+      combatant2.stars.emit(8);
+      fixture.detectChanges();
+      expect(combatantElement1.classList.contains('winner')).to.be.false;
+      expect(combatantElement2.classList.contains('winner')).to.be.true;
+    });
+    it('should not be applied when counts are equal', () => {
+      combatant1.stars.emit(7);
+      combatant2.stars.emit(7);
+      expect(nativeElement.querySelector('.winner')).to.not.exist;
+    });
+    it('should be removed again if opponent becomes null', () => {
+      combatant1.stars.emit(5);
+      combatant2.stars.emit(4);
+      combatant2.stars.emit(null);
+      fixture.detectChanges();
+      expect(nativeElement.querySelector('.winner')).to.not.exist;
+    });
+    it('should move if loser gets more', () => {
+      combatant1.stars.emit(5);
+      combatant2.stars.emit(4);
+      combatant2.stars.emit(6);
+      fixture.detectChanges();
+      expect(combatantElement1.classList.contains('winner')).to.be.false;
+      expect(combatantElement2.classList.contains('winner')).to.be.true;
+    });
+  });
+
+});

src/specs/service.github.spec.ts

@@ -190,6 +190,10 @@ describe('GithubService', () => {
             expect(resultListener.called).to.be.true;
             expect(resultListener.lastCall.args[0]).to.eql([...firstPage.body, ...secondPage.body, ...thirdPage.body]);
           });
+
+          it('should not make any further get requests', () => {
+            expect(fakeHttpService.get.callCount).to.equal(3, 'we didnt make a fourth request');
+          });
         });
       });
     });