test: add unit tests for RecipeController

Covers 6/6 methods in controller
Also added test configuration in application-mock-data-test.properties

server/src/main/resources/application-mock-data-test.properties

@@ -0,0 +1,18 @@
+spring.datasource.driverClassName=org.h2.Driver
+spring.datasource.username=sa
+spring.datasource.password=
+spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
+
+# use one of these alternatives...
+# ... purely in-memory, wiped on restart, but great for testing
+spring.datasource.url=jdbc:h2:mem:testdb
+# ... persisted on disk (in project directory)
+#spring.datasource.url=jdbc:h2:file:./h2-database
+
+# enable DB view on http://localhost:8080/h2-console
+spring.h2.console.enabled=true
+
+# strategy for table (re-)generation 
+spring.jpa.hibernate.ddl-auto=update
+# show auto-generated SQL commands
+#spring.jpa.hibernate.show_sql=true

server/src/test/java/server/api/RecipeControllerTest.java

@@ -0,0 +1,137 @@
+package server.api;
+
+
+import commons.Recipe;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.http.HttpStatus;
+import org.springframework.test.context.ActiveProfiles;
+import server.database.RecipeRepository;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.LongStream;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+// Spring Boot unit testing magic
+// Before each test the state of the repository is reset by
+// rolling back transaction of changes from previous test
+@DataJpaTest
+
+// This test sources its application profile from
+// resources/application-mock-data-test.properties
+// This config uses an in-memory database
+@ActiveProfiles("mock-data-test")
+public class RecipeControllerTest {
+    private RecipeController controller;
+    private List<Recipe> recipes;
+    private RecipeRepository recipeRepository;
+    public static final int NUM_RECIPES = 10;
+
+    // Injects a test repository into the test class
+    @Autowired
+    public RecipeControllerTest(RecipeRepository recipeRepository) {
+        this.recipeRepository = recipeRepository;
+    }
+
+    @BeforeEach
+    public void setup() {
+        recipes = LongStream
+                .range(0, NUM_RECIPES)
+                .mapToObj(x -> new Recipe(null, "Recipe " + x, List.of(), List.of()))
+                .toList();
+        controller = new RecipeController(recipeRepository);
+    }
+    @Test
+    public void createOneRecipe() {
+        controller.createRecipe(recipes.getFirst());
+
+        // There is 1 recipe in the repository
+        assertEquals(1, recipeRepository.count());
+    }
+    @Test
+    public void createManyRecipes() {
+        recipes.forEach(recipe -> controller.createRecipe(recipe));
+
+        // There are the same number of recipes in the repository as the input list
+        assertEquals(recipes.size(), recipeRepository.count());
+    }
+    @Test
+    public void getManyRecipes() {
+        recipes.forEach(recipe -> controller.createRecipe(recipe));
+
+        // The number of recipes returned is the same as the entire input list
+        assertEquals(recipes.size(), controller.getRecipes(Optional.empty()).getBody().size());
+    }
+    @Test
+    public void getSomeRecipes() {
+        final int LIMIT = 5;
+        recipes.forEach(recipe -> controller.createRecipe(recipe));
+        // The number of recipes returned is the same as the entire input list
+        assertEquals(LIMIT, controller.getRecipes(Optional.of(LIMIT)).getBody().size());
+    }
+    @Test
+    public void findOneRecipeExists() {
+        final int CHECK_INDEX = 3;
+        List<Long> ids = LongStream
+                .range(0, NUM_RECIPES)
+                .map(recipe -> controller.createRecipe(recipes.get((int) recipe)).getBody().getId())
+                .boxed().toList();
+
+        // The third item in the input list is the same as the third item retrieved from the database
+        assertEquals(
+                recipes.get(CHECK_INDEX),
+                controller.getRecipe(ids.get(CHECK_INDEX)).getBody());
+    }
+    @Test
+    public void findOneRecipeNotExists() {
+        final int CHECK_INDEX = 3;
+        // There does not exist a recipe with ID=3 since there are no items in the repository.
+        assertEquals(
+                HttpStatus.NOT_FOUND,
+                controller.getRecipe((long) CHECK_INDEX).getStatusCode());
+    }
+    @Test
+    public void deleteOneRecipeGood() {
+        final int DELETE_INDEX = 5;
+        List<Long> ids = LongStream
+                .range(0, NUM_RECIPES)
+                .map(recipe -> controller.createRecipe(recipes.get((int) recipe)).getBody().getId())
+                .boxed().toList();
+
+        // The object has been successfully deleted
+        assertEquals(HttpStatus.OK, controller.deleteRecipe(ids.get(DELETE_INDEX)).getStatusCode());
+    }
+    @Test
+    public void deleteOneRecipeCountGood() {
+        final int DELETE_INDEX = 5;
+        List<Long> ids = LongStream
+                .range(0, NUM_RECIPES)
+                .map(recipe -> controller.createRecipe(recipes.get((int) recipe)).getBody().getId())
+                .boxed().toList();
+        controller.deleteRecipe(ids.get(DELETE_INDEX));
+        // The count of items decreased by 1 after the 5th item has been removed.
+        assertEquals(ids.size() - 1,  recipeRepository.count());
+    }
+    @Test
+    public void deleteOneRecipeFail() {
+        final Long DELETE_INDEX = 5L;
+        assertEquals(HttpStatus.BAD_REQUEST, controller.deleteRecipe(DELETE_INDEX).getStatusCode());
+    }
+
+    @Test
+    public void updateOneRecipeHasNewData() {
+        final int UPDATE_INDEX = 5;
+        List<Long> ids = LongStream
+                .range(0, NUM_RECIPES)
+                .map(recipe -> controller.createRecipe(recipes.get((int) recipe)).getBody().getId())
+                .boxed().toList();
+        Recipe newRecipe = controller.getRecipe(ids.get(UPDATE_INDEX)).getBody();
+        newRecipe.setName("New recipe");
+        controller.updateRecipe(newRecipe.getId(), newRecipe);
+        assertEquals("New recipe", recipeRepository.getReferenceById(ids.get(UPDATE_INDEX)).getName());
+    }
+}