Fix bug when saving tags for recipes

src/api/endpoints/TagRestResource.ts

@@ -8,9 +8,9 @@ import {requireAdmin} from "../../middleware/authorizationMiddleware.js";
  * REST resource for tags.
  *
  * Routes:
- *   GET    /tags                    — list all tags (authenticated users)
- *   POST   /tags/create-or-update   — create or update a tag (authenticated users)
- *   DELETE /tags/:id                — delete a tag (administrators only)
+ *   GET    /tag                    — list all tags (authenticated users)
+ *   POST   /tag/create-or-update   — create or update a tag (authenticated users)
+ *   DELETE /tag/:id                — delete a tag (administrators only)
  *
  * Authentication / authorisation is assumed to be enforced by middleware
  * applied upstream (e.g. a global JWT guard). The adminOnly middleware below
@@ -22,7 +22,7 @@ const tagHandler = new TagHandler();
 
 
 /**
- * GET /tags
+ * GET /tag/all
  * Returns all available tags.
  */
 router.get("/all", async (_req: Request, res: Response, next: NextFunction) => {
@@ -35,9 +35,9 @@ router.get("/all", async (_req: Request, res: Response, next: NextFunction) => {
 });
 
 /**
- * POST /tags/create-or-update
+ * POST /tag/create-or-update
  * Creates a new tag or updates an existing one.
- * If a tag with the given descriprion already exists in the database, that tag is returned instead of creating
+ * If a tag with the given description already exists in the database, that tag is returned instead of creating
  * a duplicate.
  * Body: TagDto
  */
@@ -55,7 +55,7 @@ router.post(
 );
 
 /**
- * DELETE /tags/:id
+ * DELETE /tag/:id
  * Deletes a tag by ID. Restricted to administrators.
  * The database cascade removes all entries in the recipe_tag mapping table.
  */

src/mappers/RecipeDtoEntityMapper.ts

@@ -6,6 +6,7 @@ import { AbstractDtoEntityMapper } from "./AbstractDtoEntityMapper.js";
 import { RecipeIngredientGroupDtoEntityMapper } from "./RecipeIngredientGroupDtoEntityMapper.js";
 import { RecipeInstructionStepDtoEntityMapper } from "./RecipeInstructionStepDtoEntityMapper.js";
 import { TagDtoEntityMapper } from "./TagDtoEntityMapper.js";
+import {TagEntity} from "../entities/TagEntity.js";
 
 export class RecipeDtoEntityMapper extends AbstractDtoEntityMapper<RecipeEntity, RecipeDto> {
     constructor(
@@ -114,12 +115,15 @@ export class RecipeDtoEntityMapper extends AbstractDtoEntityMapper<RecipeEntity,
         );
 
         // --- Tags ---
-        // Tags are looked up by ID and replaced wholesale: the recipe holds
-        // references to existing tag entities, so we map each DTO to its entity
-        // form and let TypeORM sync the join table on save.
-        entity.tagList = (dto.tagList ?? []).map((tagDto) =>
-            this.tagMapper.toEntity(tagDto)
-        );
+        /* Only build a stub here instead of using the mapper to avoid causing a cascade on the tag table while
+         * updating the join table correctly. For this purpose, the ORM only needs to know the tag ID in order to
+         * signal that we are dealing with an existing tag.
+         */
+        entity.tagList = (dto.tagList ?? []).map((tagDto) => {
+            const stub = new TagEntity();
+            stub.id = tagDto.id;
+            return stub;
+        });
 
         return entity;
     }

src/repositories/RecipeRepository.ts

@@ -1,7 +1,7 @@
 import { AbstractRepository } from "./AbstractRepository.js";
 import { RecipeEntity } from "../entities/RecipeEntity.js";
 import { AppDataSource } from "../data-source.js";
-import { ILike, Like } from "typeorm";
+import { ILike } from "typeorm";
 
 export class RecipeRepository extends AbstractRepository<RecipeEntity> {
   constructor() {
@@ -19,7 +19,8 @@ export class RecipeRepository extends AbstractRepository<RecipeEntity> {
       relations: [
         'ingredientGroups', 
         'ingredientGroups.ingredients',
-        'instructionSteps'
+        'instructionSteps',
+        'tagList',
       ] 
     });
   }
@@ -46,7 +47,7 @@ export class RecipeRepository extends AbstractRepository<RecipeEntity> {
     // load existing data
     const existing = await this.repo.findOneOrFail({
       where: { id: entity.id },
-      relations: ["instructionSteps", "ingredientGroups", "ingredientGroups.ingredients"],
+      relations: ["instructionSteps", "ingredientGroups", "ingredientGroups.ingredients", "tagList"],
     });
 
     // merge new entity and existing entity