update AccountService with getById

src/main/kotlin/ltd/lulz/service/AccountService.kt

@@ -1,6 +1,7 @@
 package ltd.lulz.service
 
 import io.github.oshai.kotlinlogging.KotlinLogging
+import java.util.UUID
 import ltd.lulz.model.AccountEntity
 import ltd.lulz.repository.AccountRepository
 import org.springframework.stereotype.Service
@@ -16,4 +17,7 @@ class AccountService(
     fun create(entity: AccountEntity): Mono<AccountEntity> = accountRepository
         .save(entity)
         .doOnNext { log.debug { "account created with id: ${it.id}" } }
+
+    fun getById(id: UUID): Mono<AccountEntity> = accountRepository.findById(id)
+        .doOnNext { log.debug { "found account by id: ${it.id}" } }
 }

src/test/kotlin/ltd/lulz/service/AccountServiceTest.kt

@@ -50,4 +50,23 @@ class AccountServiceTest {
 
         verify { repository.save(any()) }
     }
+
+    @Test
+    fun `get by id`() {
+        // given
+        val capture = slot<UUID>()
+        every { repository.findById(capture(capture)) }
+            .answers { Mono.just(AccountEntity(capture.captured, name, amount)) }
+
+        // when stepped
+        StepVerifier.create(service.getById(uuid))
+            .assertNext { result ->
+                assertThat(result.id).isEqualTo(uuid)
+                assertThat(result.name).isEqualTo(name)
+                assertThat(result.amount).isEqualTo(amount)
+            }
+            .verifyComplete()
+
+        verify { repository.findById(any(UUID::class)) }
+    }
 }