test: improve unit test clarity

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

@@ -3,15 +3,19 @@ package server.api;
 
 import commons.Recipe;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Tag;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestInfo;
 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.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 import java.util.stream.LongStream;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -28,7 +32,8 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 public class RecipeControllerTest {
     private RecipeController controller;
     private List<Recipe> recipes;
-    private RecipeRepository recipeRepository;
+    private final RecipeRepository recipeRepository;
+    private List<Long> recipeIds;
     public static final int NUM_RECIPES = 10;
 
     // Injects a test repository into the test class
@@ -38,12 +43,29 @@ public class RecipeControllerTest {
     }
 
     @BeforeEach
-    public void setup() {
+    public void setup(TestInfo info) {
         recipes = LongStream
                 .range(0, NUM_RECIPES)
                 .mapToObj(x -> new Recipe(null, "Recipe " + x, List.of(), List.of()))
                 .toList();
         controller = new RecipeController(recipeRepository);
+        Set<String> tags = info.getTags();
+        List<Long> ids = new ArrayList<>();
+
+        // Some tests want initial data to be created.
+        if (tags.contains("test-from-init-data")) {
+            ids = LongStream
+                    .range(0, NUM_RECIPES)
+                    .map(idx -> recipeRepository.save(recipes.get((int) idx)).getId())
+                    .boxed().toList();
+        }
+
+        // Some tests need to know the stored IDs of objects
+        if (tags.contains("need-ids")) {
+            recipeIds = ids;
+        }
+
+        // If no tags specified, the repository is initialized as empty.
     }
     @Test
     public void createOneRecipe() {
@@ -60,31 +82,27 @@ public class RecipeControllerTest {
         assertEquals(recipes.size(), recipeRepository.count());
     }
     @Test
+    @Tag("test-from-init-data")
     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
+    @Tag("test-from-init-data")
     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
+    @Tag("test-from-init-data")
+    @Tag("need-ids")
     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());
+                controller.getRecipe(recipeIds.get(CHECK_INDEX)).getBody());
     }
     @Test
     public void findOneRecipeNotExists() {
@@ -95,26 +113,22 @@ public class RecipeControllerTest {
                 controller.getRecipe((long) CHECK_INDEX).getStatusCode());
     }
     @Test
+    @Tag("test-from-init-data")
+    @Tag("need-ids")
     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());
+        assertEquals(HttpStatus.OK, controller.deleteRecipe(recipeIds.get(DELETE_INDEX)).getStatusCode());
     }
     @Test
+    @Tag("test-from-init-data")
+    @Tag("need-ids")
     public void deleteOneRecipeCountGood() {
         final int DELETE_INDEX = 5;
-        List<Long> ids = LongStream
+        controller.deleteRecipe(recipeIds.get(DELETE_INDEX));
-                .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());
+        assertEquals(recipeIds.size() - 1,  recipeRepository.count());
     }
     @Test
     public void deleteOneRecipeFail() {
@@ -123,15 +137,13 @@ public class RecipeControllerTest {
     }
 
     @Test
+    @Tag("test-from-init-data")
+    @Tag("need-ids")
     public void updateOneRecipeHasNewData() {
         final int UPDATE_INDEX = 5;
-        List<Long> ids = LongStream
+        Recipe newRecipe = controller.getRecipe(recipeIds.get(UPDATE_INDEX)).getBody();
-                .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());
+        assertEquals("New recipe", recipeRepository.getReferenceById(recipeIds.get(UPDATE_INDEX)).getName());
     }
 }