diff --git a/gulpfile.js b/gulpfile.js
index 40590d7c2..9e4fe20c6 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -96,7 +96,7 @@ async function backTestOnce(done) {
             let options = {
                 errorOnFail: false,
                 config: {
-                    random: false
+                    random: true
                 }
             };
 
diff --git a/modules/ticket/back/methods/ticket-request/confirm.js b/modules/ticket/back/methods/ticket-request/confirm.js
index 0bc387fe8..67781c6c2 100644
--- a/modules/ticket/back/methods/ticket-request/confirm.js
+++ b/modules/ticket/back/methods/ticket-request/confirm.js
@@ -48,31 +48,26 @@ module.exports = Self => {
                 include: {relation: 'ticket'}
             }, options);
 
-            const res = await models.Item.getVisibleAvailable(ctx.args.itemFk, request.ticket().warehouseFk, request.ticket().shipped);
+            const itemStock = await models.Item.getVisibleAvailable(ctx.args.itemFk, request.ticket().warehouseFk, request.ticket().shipped);
+            const isAvailable = itemStock.available > 0;
 
-            if (res.available < 0)
+            if (!isAvailable)
                 throw new UserError(`This item is not available`);
 
-            if (request.saleFk) {
-                sale = await models.Sale.findById(request.saleFk, null, options);
-                await sale.updateAttributes({
-                    itemFk: ctx.args.itemFk,
-                    quantity: ctx.args.quantity,
-                    concept: item.name,
-                }, options);
-            } else {
-                sale = await models.Sale.create({
-                    ticketFk: request.ticketFk,
-                    itemFk: ctx.args.itemFk,
-                    quantity: ctx.args.quantity,
-                    concept: item.name
-                }, options);
-                await request.updateAttributes({
-                    saleFk: sale.id,
-                    itemFk: sale.itemFk,
-                    isOk: true
-                }, options);
-            }
+            if (request.saleFk)
+                throw new UserError(`This request already contains a sale`);
+
+            sale = await models.Sale.create({
+                ticketFk: request.ticketFk,
+                itemFk: ctx.args.itemFk,
+                quantity: ctx.args.quantity,
+                concept: item.name
+            }, options);
+            await request.updateAttributes({
+                saleFk: sale.id,
+                itemFk: sale.itemFk,
+                isOk: true
+            }, options);
 
             query = `CALL vn.sale_calculateComponent(?, NULL)`;
             await Self.rawSql(query, [sale.id], options);
diff --git a/modules/ticket/back/methods/ticket-request/specs/confirm.spec.js b/modules/ticket/back/methods/ticket-request/specs/confirm.spec.js
index 134ccca40..5d902ae5d 100644
--- a/modules/ticket/back/methods/ticket-request/specs/confirm.spec.js
+++ b/modules/ticket/back/methods/ticket-request/specs/confirm.spec.js
@@ -2,7 +2,6 @@ const app = require('vn-loopback/server/server');
 
 describe('ticket-request confirm()', () => {
     let originalRequest;
-    let originalSale;
     let createdSaleId;
     let ctx = {
         req: {
@@ -16,8 +15,13 @@ describe('ticket-request confirm()', () => {
 
     afterAll(async done => {
         await originalRequest.updateAttributes(originalRequest);
-        await originalSale.updateAttributes(originalSale);
         await app.models.Sale.destroyById(createdSaleId);
+        await app.models.Sale.destroyById(addedSale.id);
+
+        await app.models.Item.rawSql(`
+            TRUNCATE TABLE cache.last_buy
+        `);
+
         done();
     });
 
@@ -56,10 +60,9 @@ describe('ticket-request confirm()', () => {
         expect(error.message).toEqual(`This item is not available`);
     });
 
-    it(`should update the sale details if the request already contains a sale id`, async() => {
+    it(`should throw if there's a sale id`, async() => {
         const requestId = 4;
-        const saleId = 11;
-        const itemId = 1;
+        const itemId = 2;
         const quantity = 10;
 
         ctx.args = {
@@ -68,17 +71,15 @@ describe('ticket-request confirm()', () => {
             quantity: quantity
         };
 
-        originalRequest = await app.models.TicketRequest.findById(requestId);
-        originalSale = await app.models.Sale.findById(saleId);
+        let error;
 
-        const request = await app.models.TicketRequest.findById(requestId);
-        await request.updateAttributes({saleFk: saleId});
-        await app.models.TicketRequest.confirm(ctx);
+        try {
+            await app.models.TicketRequest.confirm(ctx);
+        } catch (err) {
+            error = err;
+        }
 
-        let updatedSale = await app.models.Sale.findById(saleId);
-
-        expect(updatedSale.itemFk).toEqual(itemId);
-        expect(updatedSale.quantity).toEqual(quantity);
+        expect(error.message).toEqual(`This request already contains a sale`);
     });
 
     it(`should create a new sale for the the request if there's no sale id`, async() => {
@@ -86,6 +87,8 @@ describe('ticket-request confirm()', () => {
         const itemId = 1;
         const quantity = 10;
 
+        originalRequest = await app.models.TicketRequest.findById(requestId);
+
         ctx.args = {
             itemFk: itemId,
             id: requestId,
diff --git a/modules/ticket/back/methods/ticket/priceDifference.js b/modules/ticket/back/methods/ticket/priceDifference.js
index a303412fe..2631481c6 100644
--- a/modules/ticket/back/methods/ticket/priceDifference.js
+++ b/modules/ticket/back/methods/ticket/priceDifference.js
@@ -87,15 +87,14 @@ module.exports = Self => {
         const map = new Map();
 
         // Sale price component, one per sale
-        difComponents.forEach(difComponent => {
+        for (difComponent of difComponents)
             map.set(difComponent.saleFk, difComponent);
-        });
 
         function round(value) {
             return Math.round(value * 100) / 100;
         }
 
-        salesObj.items.forEach(sale => {
+        for (sale of salesObj.items) {
             const difComponent = map.get(sale.id);
 
             if (difComponent) {
@@ -110,7 +109,7 @@ module.exports = Self => {
 
             salesObj.totalUnitPrice += sale.price;
             salesObj.totalUnitPrice = round(salesObj.totalUnitPrice);
-        });
+        }
 
         return salesObj;
     };