fix: the app was crashing when multiple connection where required. I replaced pg.Client by pg.Pool, it should enhanced the usability and durability

API-Project/src/database/connection.ts

@@ -1,12 +1,11 @@
-import { Client } from "pg"
+import { Pool, PoolClient } from "pg"
 
 
 export class Connection {
-  public client:Client
+  private pool:Pool
-  clientIsConnected:boolean = false
 
   constructor() {
-    this.client = new Client({
+    this.pool = new Pool({
       user: process.env.DB_USERNAME,
       host: process.env.DB_DBHOST,
       database: process.env.DB_DBNAME,
@@ -15,10 +14,7 @@ export class Connection {
     })
   }
 
-  public async connect() {
+  public async getPoolClient() : Promise<PoolClient> {
-    if (!this.clientIsConnected) {
+    return await this.pool.connect()
-      await this.client.connect()
-      this.clientIsConnected = true
-    }
   }
 }

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

@@ -9,9 +9,11 @@ export class IngredientsGateway {
     }
 
     async getAll() : Promise<Ingredient[]> {
-        this.connection.connect()
+        const client = await this.connection.getPoolClient()
 
-        const res = await this.connection.client.query('SELECT * FROM Ingredients ORDER BY id')
+        const res = await client.query('SELECT * FROM Ingredients ORDER BY id')
+
+        client.release()
 
         let ingredients:Ingredient[] = []
 
@@ -24,14 +26,16 @@ export class IngredientsGateway {
     }
 
     async findOneById(id: number) : Promise<Ingredient | null> {
-        this.connection.connect()
+        const client = await this.connection.getPoolClient()
 
         const query = {
             text: 'SELECT * FROM Ingredients WHERE id =$1',
             values: [id],
         }
         
-        const res = await this.connection.client.query(query)
+        const res = await client.query(query)
+
+        client.release()
 
         if (res.rowCount != 1) {
             return null
@@ -43,15 +47,16 @@ export class IngredientsGateway {
     }
 
     async findIngredientsForRecipe(id: number): Promise<any> {
-        this.connection.connect();
+        const client = await this.connection.getPoolClient()
     
         const query = {
             text: 'SELECT i.name, i.id FROM Ingredients i, Composed c WHERE c.idRecipe =$1 AND i.id = c.idIngredient',
             values: [id],
         };
     
-        const res = await this.connection.client.query(query);
+        const res = await client.query(query);
-        console.log(res)
+
+        client.release()
     
         if (res.rowCount === 0) {
             return null;
@@ -62,7 +67,6 @@ export class IngredientsGateway {
             name: row.name,
             id: Number(row.id), // Conversion de l'identifiant en nombre
         }));
-        console.log(ingredients);
     
         return ingredients as Ingredient[];
     }

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

@@ -15,8 +15,9 @@ export class RecipeGateway {
     }
 
     async getAll() : Promise<Recipe[]> {
-        this.connection.connect()
+        const client = await this.connection.getPoolClient()
-        const res = await this.connection.client.query('SELECT * FROM Recipes ORDER BY id');
+        const res = await client.query('SELECT * FROM Recipes ORDER BY id');
+        client.release()
         
         const steps: string[] = [];
         let recipes: Recipe[] = []
@@ -28,20 +29,20 @@ export class RecipeGateway {
             recipes.push(recipe);
         }
 
-        console.log(recipes);
-
         return recipes
     }
 
     async getById(id: number) : Promise<Recipe | null>{
-        this.connection.connect()
+        const client = await this.connection.getPoolClient()
 
         const query = {
             text: 'SELECT * FROM Recipes WHERE id =$1',
             values: [id],
         }
 
-        const res = await this.connection.client.query(query)
+        const res = await client.query(query)
+
+        client.release()
 
         if (res.rowCount != 1) {
             return null

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

@@ -9,14 +9,16 @@ export class StepsGateway {
 
 
     async getForRecipes(id: number): Promise<string[]> {
-        this.connection.connect();
+        const client = await this.connection.getPoolClient()
     
         const query = {
             text: 'SELECT action FROM Steps WHERE idRecipe = $1 ORDER BY numstep',
             values: [id],
         };
     
-        const res = await this.connection.client.query(query);
+        const res = await client.query(query);
+
+        client.release()
     
         const steps = res.rows.map(row => row.action);