Reducer and mapping tests

chapter08/src/regionsApp/store.js

@@ -3,6 +3,6 @@
 import { createStore, applyMiddleware } from "redux";
 import thunk from "redux-thunk";
 
-import { reducer } from "./worlds.reducer.js";
+import { reducer } from "./world.reducer";
 
 export const store = createStore(reducer, applyMiddleware(thunk));

chapter09/package.json

@@ -42,6 +42,7 @@
         "start": "react-app-rewired start",
         "build": "react-app-rewired build",
         "test": "react-app-rewired test --env=jsdom",
+        "coverage": "react-app-rewired test --env=jsdom --coverage --no-cache",
         "eject": "react-app-rewired eject",
         "flow": "flow",
         "addTypes": "flow-typed install",

chapter09/src/regionsApp/regionsTable.connected.js

@@ -4,7 +4,7 @@ import { connect } from "react-redux";
 
 import { RegionsTable } from "./regionsTable.component";
 
-const getProps = state => ({
+export const getProps = state => ({
     list: state.regions,
     loading: state.loadingRegions
 });

chapter09/src/regionsApp/regionsTable.connected.test.js

@@ -0,0 +1,27 @@
+/* @flow */
+
+import Enzyme from "enzyme/build";
+import Adapter from "enzyme-adapter-react-16/build";
+
+import { getProps } from "./regionsTable.connected.js";
+
+Enzyme.configure({ adapter: new Adapter() });
+
+describe("getProps for RegionsTable", () => {
+    it("should extract regions and loading", () => {
+        const initialState = {
+            loadingCountries: false,
+            currentCountry: "whatever",
+            countries: [{ other: 1 }, { other: 2 }, { other: 3 }],
+            loadingRegions: false,
+            regions: [{ something: 1 }, { something: 2 }]
+        };
+        const initialJSON = JSON.stringify(initialState);
+
+        expect(getProps(initialState)).toEqual({
+            list: [{ something: 1 }, { something: 2 }],
+            loading: false
+        });
+        expect(JSON.stringify(initialState)).toBe(initialJSON);
+    });
+});

chapter09/src/regionsApp/store.js

@@ -5,7 +5,7 @@ import thunk from "redux-thunk";
 import { createLogger } from "redux-logger";
 import { composeWithDevTools } from "redux-devtools-extension";
 
-import { reducer } from "./worlds.reducer.js";
+import { reducer } from "./world.reducer.js";
 
 const logger = createLogger({ duration: true });
 

chapter09/src/regionsApp/world.reducer.test.js

@@ -0,0 +1,79 @@
+/* @flow */
+
+import Enzyme from "enzyme/build";
+import Adapter from "enzyme-adapter-react-16/build";
+
+import { reducer } from "./world.reducer.js";
+import { countriesRequest, regionsSuccess } from "./world.actions.js";
+
+Enzyme.configure({ adapter: new Adapter() });
+
+describe("The countries and regions reducer", () => {
+    it("should process countryRequest actions", () => {
+        const initialState = {
+            loadingCountries: false,
+            currentCountry: "whatever",
+            countries: [{}, {}, {}],
+            loadingRegions: false,
+            regions: [{}, {}]
+        };
+
+        const initialJSON = JSON.stringify(initialState);
+
+        expect(reducer(initialState, countriesRequest())).toEqual({
+            loadingCountries: true,
+            currentCountry: "whatever",
+            countries: [],
+            loadingRegions: false,
+            regions: [{}, {}]
+        });
+
+        expect(JSON.stringify(initialState)).toBe(initialJSON);
+    });
+
+    it("should process regionsSuccess actions", () => {
+        const initialState = {
+            loadingCountries: false,
+            currentCountry: "whatever",
+            countries: [{}, {}, {}],
+            loadingRegions: true,
+            regions: []
+        };
+
+        const initialJSON = JSON.stringify(initialState);
+
+        expect(
+            reducer(
+                initialState,
+                regionsSuccess([
+                    { something: 1 },
+                    { something: 2 },
+                    { something: 3 }
+                ])
+            )
+        ).toEqual({
+            loadingCountries: false,
+            currentCountry: "whatever",
+            countries: [{}, {}, {}],
+            loadingRegions: false,
+            regions: [{ something: 1 }, { something: 2 }, { something: 3 }]
+        });
+
+        expect(JSON.stringify(initialState)).toBe(initialJSON);
+    });
+
+    it("should return the initial state for unknown actions", () => {
+        const initialState = {
+            loadingCountries: false,
+            currentCountry: "whatever",
+            countries: [{}, {}, {}],
+            loadingRegions: true,
+            regions: []
+        };
+        const initialJSON = JSON.stringify(initialState);
+        expect(
+            JSON.stringify(reducer(initialState, { actionType: "other" }))
+        ).toBe(initialJSON);
+        expect(JSON.stringify(initialState)).toBe(initialJSON);
+    });
+});