feat: add IngredientsClassesGateway

API-Project/src/gateways/ingredientsClasses.gateway.ts

@@ -0,0 +1,36 @@
+import { Connection } from "../database/connection"
+import { IngredientsClasses } from "../types/ingredientsClasses"
+
+export class IngredientsClassesGateway {
+    connection: Connection
+
+    constructor() {
+        this.connection = new Connection()
+    }
+
+
+    async getForIngredient(id: number): Promise<IngredientsClasses[]> {
+        const client = await this.connection.getPoolClient()
+        let classes : IngredientsClasses[] = []
+    
+        const query = {
+            text: 'SELECT name FROM Composed, IngredientsClasses WHERE idIngredient = $1 AND idClass = id',
+            values: [id],
+        }
+    
+        const res = await client.query(query)
+
+        client.release()
+    
+        for (let row of res.rows) {
+            const classNameString: string = row.name;
+            const classNameEnum: IngredientsClasses = IngredientsClasses[classNameString as keyof typeof IngredientsClasses];
+
+            if (classNameEnum !== undefined) {
+                classes.push(classNameEnum);
+            }
+        }
+    
+        return classes
+    }
+}

API-Project/src/types/ingredientsClasses.ts

@@ -1,4 +1,4 @@
-enum IngredientsClasses {
+export enum IngredientsClasses {
     DairyFree = 'DAIRY_FREE', 
     GlutenFree = 'GLUTEN_FREE', 
     Porcless = 'PORCLESS',