add tests for ShopController

src/main/kotlin/com/example/demo/controllers/ShopController.kt

@@ -14,11 +14,9 @@ import org.springframework.web.bind.annotation.RestController
 class ShopController (
     @field:Autowired private val shopProvider: ShopProvider,
 ) {
-    @GetMapping(value = ["/shop/common-info"], produces = ["application/json"] )
+    @GetMapping(value = ["/shop/common-info"], produces = ["application/json"])
     @ResponseBody
     fun commonInfo(response: HttpServletResponse): String {
-        response.contentType = "application/json"
-
         val shop = shopProvider.getRandomShop()
 
         if (shop == null) {

src/main/kotlin/com/example/demo/provider/html/HtmlProvider.kt

@@ -19,7 +19,7 @@ fun renderProductTable(): String {
                 }
             }
 
-            val products = getProducts()
+            val products = getInnerProducts()
             for ((i, product) in products.withIndex()) {
                 tr {
                     td (color = getCellColor(0, i+1)) {

src/main/kotlin/com/example/demo/provider/html/InnerProduct.kt

@@ -0,0 +1,11 @@
+package com.example.demo.provider.html
+
+data class InnerProduct(val description: String, val price: Double, val popularity: Int)
+
+fun getInnerProducts(): Set<InnerProduct> {
+    return setOf(
+        InnerProduct("one", 12.0, 12),
+        InnerProduct("two", 13.0, 20),
+        InnerProduct("three", 14.0, 50)
+    )
+}

src/main/kotlin/com/example/demo/provider/html/Product.kt

@@ -1,11 +0,0 @@
-package com.example.demo.provider.html
-
-data class Product(val description: String, val price: Double, val popularity: Int)
-
-fun getProducts(): Set<Product> {
-    return setOf(
-        Product("one", 12.0, 12),
-        Product("two", 13.0, 20),
-        Product("three", 14.0, 50)
-    )
-}

src/test/kotlin/com/example/demo/DemoApplicationTests.kt

@@ -1,13 +0,0 @@
-package com.example.demo
-
-import org.junit.jupiter.api.Test
-import org.springframework.boot.test.context.SpringBootTest
-
-@SpringBootTest
-class DemoApplicationTests {
-
-	@Test
-	fun contextLoads() {
-	}
-
-}

src/test/kotlin/com/example/demo/controllers/GreetingControllerTest.kt

@@ -11,7 +11,6 @@ import kotlin.test.Test
 
 @WebMvcTest(GreetingController::class)
 class GreetingControllerTest(@Autowired val mockMvc: MockMvc) {
-
     @Test
     fun greetings_shouldSeeGreetingMessage() {
         mockMvc.perform(get("/greeting"))

src/test/kotlin/com/example/demo/controllers/ShopControllerTest.kt

@@ -0,0 +1,58 @@
+package com.example.demo.controllers
+
+import com.example.demo.models.*
+import com.example.demo.provider.ShopProvider
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.whenever
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest
+import org.springframework.boot.test.mock.mockito.MockBean
+import org.springframework.test.web.servlet.MockMvc
+import org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers.content
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers.status
+import kotlin.test.Test
+
+@WebMvcTest(ShopController::class)
+class ShopControllerTest(@Autowired val mockMvc: MockMvc) {
+    @MockBean
+    private lateinit var shopProvider: ShopProvider
+
+    @Test
+    fun commonInfo_shouldSeeSuccessResponseJson() {
+        val shopMock = Shop(name="shop", customers= listOf(
+            Customer(
+                name = "cus-one",
+                city = City(name= "city-one"),
+                orders = listOf(
+                    Order(products = listOf(Product(name = "one", price = 11.2)), isDelivered = false),
+                    Order(products = listOf(Product(name = "two", price = 13.2)), isDelivered = false),
+                    Order(products = listOf(Product(name = "three", price = 15.2)), isDelivered = true),
+                )
+            ),
+            Customer(
+                name = "cus-two",
+                city = City(name= "city-two"),
+                orders = listOf(
+                    Order(products = listOf(Product(name = "one", price = 12.2)), isDelivered = false),
+                    Order(products = listOf(Product(name = "two", price = 13.2)), isDelivered = true),
+                    Order(products = listOf(Product(name = "four", price = 14.2)), isDelivered = true),
+                )
+            ),
+        ))
+
+        val expectedJson: String = """{
+            |"customers": {"withMoreUndeliveredOrdersThanDelivered": ["cus-one"]},
+            |"products": {"orderedByAllCustomers": ["two"]}
+            |}""".trimMargin()
+
+        whenever(
+            shopProvider.getRandomShop()
+        ) doReturn (shopMock)
+
+        mockMvc.perform(get("/shop/common-info"))
+            .andExpect(status().isOk)
+            .andExpect(content().contentType("application/json"))
+            .andExpect(content().json(expectedJson))
+    }
+}