Add routes and fix mappers and migration scripts

src/migrations/1701234567890-ConvertRoleToEnum.ts

@@ -1,44 +1,78 @@
 import { MigrationInterface, QueryRunner } from "typeorm";
 
 /**
- * Migration to convert role column from varchar to enum
+ * Converts the `role` column on the `user` table from varchar to a proper
+ * PostgreSQL enum type.
  *
- * File name should be: TIMESTAMP-ConvertRoleToEnum.ts
- * Example: 1701234567890-ConvertRoleToEnum.ts
+ * Existing rows are safe: the varchar values 'user' and 'admin' inserted by
+ * CreateUserTable1661234567890 match the enum members exactly, so the USING
+ * cast succeeds without any data transformation.
  *
- * Place in: src/migrations/
+ * down() reverts cleanly by casting back to text and dropping the enum type.
  */
 export class ConvertRoleToEnum1701234567890 implements MigrationInterface {
     public async up(queryRunner: QueryRunner): Promise<void> {
+        // Create the enum type if it doesn't already exist
         await queryRunner.query(`
-      DO $$ BEGIN
-        CREATE TYPE user_role_enum AS ENUM ('user', 'admin');
-      EXCEPTION
-        WHEN duplicate_object THEN null;
-      END $$;
-    `);
+            DO $$ BEGIN
+                CREATE TYPE user_role_enum AS ENUM ('user', 'admin');
+            EXCEPTION
+                WHEN duplicate_object THEN null;
+            END $$;
+        `);
 
+        // Ensure any existing role values that differ only by whitespace or
+        // casing are normalised before the cast
         await queryRunner.query(`
-      ALTER TABLE "user" 
-      ALTER COLUMN "role" TYPE user_role_enum 
-      USING "role"::user_role_enum;
-    `);
+            UPDATE "user"
+            SET "role" = LOWER(TRIM("role"))
+            WHERE "role" IS NOT NULL;
+        `);
 
+        // Drop the varchar default before retyping — PostgreSQL cannot cast it
+        // automatically and will reject the ALTER COLUMN otherwise
         await queryRunner.query(`
-      ALTER TABLE "user" 
-      ALTER COLUMN "role" SET DEFAULT 'user';
-    `);
+            ALTER TABLE "user"
+                ALTER COLUMN "role" DROP DEFAULT;
+        `);
+
+        // Convert the column — existing 'user' and 'admin' values cast directly
+        await queryRunner.query(`
+            ALTER TABLE "user"
+            ALTER COLUMN "role" TYPE user_role_enum
+            USING "role"::user_role_enum;
+        `);
+
+        // Re-apply the default using the enum literal
+        await queryRunner.query(`
+            ALTER TABLE "user"
+            ALTER COLUMN "role" SET DEFAULT 'user'::user_role_enum;
+        `);
     }
 
     public async down(queryRunner: QueryRunner): Promise<void> {
+        // Drop the enum default first so the column can be retyped
         await queryRunner.query(`
-      ALTER TABLE "user" 
-      ALTER COLUMN "role" TYPE varchar 
-      USING "role"::text;
-    `);
+            ALTER TABLE "user"
+                ALTER COLUMN "role" DROP DEFAULT;
+        `);
 
+        // Cast enum values back to plain text
         await queryRunner.query(`
-      DROP TYPE IF EXISTS user_role_enum;
-    `);
+            ALTER TABLE "user"
+            ALTER COLUMN "role" TYPE varchar
+            USING "role"::text;
+        `);
+
+        // Restore the original varchar default
+        await queryRunner.query(`
+            ALTER TABLE "user"
+                ALTER COLUMN "role" SET DEFAULT 'user';
+        `);
+
+        // Drop the enum type — only safe once no column references it
+        await queryRunner.query(`
+            DROP TYPE IF EXISTS user_role_enum;
+        `);
     }
 }

src/migrations/1771658108802-CreateTagTable.ts

@@ -1,4 +1,4 @@
-import {MigrationInterface, QueryRunner, Table} from "typeorm";
+import {MigrationInterface, QueryRunner, Table, TableUnique} from "typeorm";
 
 /**
  * Creates the `tag` table.
@@ -15,6 +15,7 @@ export class CreateTagTable1771658108802 implements MigrationInterface {
                         type: "uuid",
                         isPrimary: true,
                         generationStrategy: "uuid",
+                        isGenerated: true,
                         default: "uuid_generate_v4()",
                     },
                     {
@@ -38,9 +39,20 @@ export class CreateTagTable1771658108802 implements MigrationInterface {
             }),
             true // ifNotExists
         );
+
+        // Add a unique constraint on desciption
+        await queryRunner.createUniqueConstraint(
+            "tag",
+            new TableUnique({
+                columnNames: ["description"],
+                name: "UQ_tag_description",
+            })
+        );
     }
 
     public async down(queryRunner: QueryRunner): Promise<void> {
+        // Drop the unique constraint first
+        await queryRunner.dropUniqueConstraint("tag", "UQ_tag_description");
         await queryRunner.dropTable("tag", true);
     }
 }