Added tests for teamByIdReducer

Author: aaryaneil

src/reducers/__tests__/teamByIdReducer.test.js

@@ -0,0 +1,28 @@
+import { teamByIdReducer } from '../teamByIdReducer';
+import { GET_TEAM_BY_ID } from '../../constants/team';
+
+
+describe('teamByIdReducer', () => {
+  it('should return the initial state when state is undefined', () => {
+    const initialState = null;
+    const action = {};
+    expect(teamByIdReducer(undefined, action)).toBe(initialState);
+  });
+
+  it('should return the current state when action type does not match', () => {
+    const currentState = { id: 1, name: 'Team A' };
+    const action = { type: 'UNKNOWN_ACTION', payload: { id: 2, name: 'Team B' } };
+    expect(teamByIdReducer(currentState, action)).toBe(currentState);
+  });
+
+  it('should return the new state when action type is GET_TEAM_BY_ID', () => {
+    const action = { type: GET_TEAM_BY_ID, payload: { id: 2, name: 'Team B' } };
+    expect(teamByIdReducer(null, action)).toEqual(action.payload);
+  });
+
+  it('should update the state with the new team when action type is GET_TEAM_BY_ID', () => {
+    const currentState = { id: 1, name: 'Team A' };
+    const action = { type: GET_TEAM_BY_ID, payload: { id: 2, name: 'Team B' } };
+    expect(teamByIdReducer(currentState, action)).toEqual(action.payload);
+  });
+});