add product repository, controller, tests

src/main/kotlin/com/example/demo/AppConfig.kt

@@ -4,8 +4,10 @@ import com.example.demo.provider.MockedShopProvider
 import com.example.demo.provider.ShopProvider
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories
 
 @Configuration
+@EnableJpaRepositories(basePackages = ["com.example.demo.providers"])
 class AppConfig {
     @Bean
     fun shopProvider(): ShopProvider{

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

@@ -0,0 +1,25 @@
+package com.example.demo.controllers
+
+import com.example.demo.exceptions.NotFoundException
+import com.example.demo.provider.ProductRepository
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.encodeToJsonElement
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.web.bind.annotation.*
+import java.util.*
+
+@RestController
+@RequestMapping(value = ["/api/product"])
+class ProductController(
+    @Autowired val productRepository: ProductRepository
+) {
+    @GetMapping(value = ["{guid}"], produces = ["application/json"])
+    @ResponseBody
+    fun getProduct(
+        @PathVariable guid: UUID
+    ): String {
+        val product = productRepository.findByGuid(guid = guid) ?: throw NotFoundException()
+
+        return Json.encodeToJsonElement(value = product).toString()
+    }
+}

src/main/kotlin/com/example/demo/provider/ProductRepository.kt

@@ -0,0 +1,13 @@
+package com.example.demo.provider
+
+import com.example.demo.models.Product
+import org.springframework.data.jpa.repository.Query
+import org.springframework.data.repository.CrudRepository
+import org.springframework.stereotype.Repository
+import java.util.*
+
+@Repository
+interface ProductRepository: CrudRepository<Product, Long> {
+    @Query(value = "SELECT * FROM Product WHERE guid = :guid")
+    fun findByGuid(guid: UUID): Product?
+}

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

@@ -0,0 +1,66 @@
+package com.example.demo.controllers
+
+import com.example.demo.models.Product
+import com.example.demo.provider.ProductRepository
+import com.example.demo.responses.ResponseStatus
+import org.hamcrest.Matchers.nullValue
+import org.junit.jupiter.api.Test
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.eq
+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.get
+import java.time.OffsetDateTime
+import java.time.format.DateTimeFormatter
+import java.util.*
+
+@WebMvcTest(ProductController::class)
+class ProductControllerTest(@Autowired val mockMvc: MockMvc) {
+    @MockBean
+    private lateinit var productRepository: ProductRepository
+
+    @Test
+    fun getProduct_success() {
+        val guid = UUID.randomUUID()
+        val now = OffsetDateTime.now()
+        val product = Product(
+            id = 12,
+            guid = guid,
+            name = "some",
+            description = null,
+            price = 11130,
+            createdAt = now,
+            updatedAt = null,
+        )
+
+        whenever(productRepository.findByGuid(
+            eq(guid),
+        )) doReturn product
+
+        mockMvc.get("/api/product/$guid")
+            .andExpect { status { status { isOk() } } }
+            .andExpect { content { contentType("application/json") } }
+            .andExpect { jsonPath("\$.id") { value(product.id.toString()) } }
+            .andExpect { jsonPath("\$.guid") { value(guid.toString()) } }
+            .andExpect { jsonPath("\$.name") { value("some") } }
+            .andExpect { jsonPath("\$.createdAt") { value(now.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME)) } }
+            .andExpect { jsonPath("\$.updatedAt") { value(nullValue()) } }
+    }
+
+    @Test
+    fun getProduct_notFound() {
+        val guid = UUID.randomUUID()
+
+        whenever(productRepository.findByGuid(
+            eq(guid),
+        )) doReturn null
+
+        mockMvc.get("/api/product/$guid")
+            .andExpect { status { status { isNotFound() } } }
+            .andExpect { content { contentType("application/json") } }
+            .andExpect { jsonPath("\$.status") { value(ResponseStatus.NOT_FOUND.status) } }
+    }
+}