Add Step and QuizStep types

Author: santakadev

examples/typescript/ts-step_shotgun_surgery-01_base/src/Application/GetStepDuration.ts

@@ -1,13 +1,16 @@
 import StepId from '../Domain/StepId'
 import StepRepository from '../Domain/StepRepository'
+import VideoStep from "../Domain/VideoStep";
 
 class GetStepDuration {
     constructor(private repository: StepRepository) {
     }
 
     execute(stepId: string): number {
         const step = this.repository.find(new StepId(stepId))
-        return step.getVideoDuration()
+        return step instanceof VideoStep ?
+            step.getVideoDuration() :
+            step.totalQuestions;
     }
 }
 

examples/typescript/ts-step_shotgun_surgery-01_base/src/Domain/QuizStep.ts

@@ -0,0 +1,17 @@
+import Step from "./Step";
+import StepId from "./StepId";
+
+class QuizStep extends Step {
+    constructor(
+        stepId: StepId,
+        public readonly totalQuestions: Number
+    ) {
+        super(stepId);
+    }
+
+    type(): string {
+        return 'quiz'
+    }
+}
+
+export default QuizStep

examples/typescript/ts-step_shotgun_surgery-01_base/src/Domain/Step.ts

@@ -1,18 +1,11 @@
 import StepId from "./StepId";
 
-class Step {
-    constructor(
-        private id: StepId,
-        private videoDuration: number
-    ) {}
+abstract class Step {
 
-    type(): string {
-        return 'video'
+    protected constructor(private readonly _id: StepId) {
     }
 
-    getVideoDuration(): number {
-        return this.videoDuration
-    }
+    abstract type();
 }
 
 export default Step

examples/typescript/ts-step_shotgun_surgery-01_base/src/Domain/StepRepository.ts

@@ -1,5 +1,5 @@
-import Step from './Step'
 import StepId from './StepId'
+import Step from "./Step";
 
 interface StepRepository {
     find(stepId: StepId): Step

examples/typescript/ts-step_shotgun_surgery-01_base/src/Domain/VideoStep.ts

@@ -0,0 +1,21 @@
+import StepId from "./StepId";
+import Step from "./Step";
+
+class VideoStep extends Step {
+    constructor(
+        stepId: StepId,
+        private videoDuration: number
+    ) {
+        super(stepId)
+    }
+
+    type(): string {
+        return 'video'
+    }
+
+    getVideoDuration(): number {
+        return this.videoDuration
+    }
+}
+
+export default VideoStep

examples/typescript/ts-step_shotgun_surgery-01_base/tests/Application/GetStepDuration.test.ts

@@ -1,14 +1,26 @@
 import GetStepDuration from '../../src/Application/GetStepDuration';
 import StepId from "../../src/Domain/StepId";
-import Step from "../../src/Domain/Step";
+import VideoStep from "../../src/Domain/VideoStep";
+import QuizStep from "../../src/Domain/QuizStep";
 
 test('should get the video step duration', () => {
     const stepId = new StepId('stepId')
-    const step = new Step(stepId, 13)
+    const step = new VideoStep(stepId, 13)
     const stepRepository = {
         find: jest.fn((stepId: StepId) => step)
     }
     const getStepDuration = new GetStepDuration(stepRepository)
 
     expect(getStepDuration.execute(stepId.value())).toBe(13)
+});
+
+test('should get the quiz step duration', () => {
+    const stepId = new StepId('stepId')
+    const step = new QuizStep(stepId, 5)
+    const stepRepository = {
+        find: jest.fn((stepId: StepId) => step)
+    }
+    const getStepDuration = new GetStepDuration(stepRepository)
+
+    expect(getStepDuration.execute(stepId.value())).toBe(5)
 });