Fix variant stock input

src/products/components/ProductVariantCreatePage/ProductVariantCreatePage.tsx

@@ -28,7 +28,7 @@ interface ProductVariantCreatePageFormData {
   costPrice: string;
   images: string[];
   priceOverride: string;
-  quantity: number;
+  quantity: string;
   sku: string;
 }
 
@@ -82,7 +82,7 @@ const ProductVariantCreatePage: React.FC<ProductVariantCreatePageProps> = ({
     costPrice: "",
     images: maybe(() => product.images.map(image => image.id)),
     priceOverride: "",
-    quantity: 0,
+    quantity: "0",
     sku: ""
   };
 

src/products/components/ProductVariantPage/ProductVariantPage.tsx

@@ -28,7 +28,7 @@ import ProductVariantStock from "../ProductVariantStock";
 export interface ProductVariantPageFormData {
   costPrice: string;
   priceOverride: string;
-  quantity: number;
+  quantity: string;
   sku: string;
 }
 
@@ -92,7 +92,7 @@ const ProductVariantPage: React.FC<ProductVariantPageProps> = ({
   const initialForm: ProductVariantPageFormData = {
     costPrice: maybe(() => variant.costPrice.amount.toString(), ""),
     priceOverride: maybe(() => variant.priceOverride.amount.toString(), ""),
-    quantity: maybe(() => variant.quantity, 0),
+    quantity: maybe(() => variant.quantity.toString(), "0"),
     sku: maybe(() => variant.sku, "")
   };
 

src/products/components/ProductVariantStock/ProductVariantStock.tsx

@@ -24,7 +24,7 @@ interface ProductVariantStockProps {
     sku?: string;
   };
   sku: string;
-  quantity: number;
+  quantity: string;
   stockAllocated?: number;
   loading?: boolean;
   onChange(event: any);

src/products/views/ProductVariant.tsx

@@ -127,7 +127,7 @@ export const ProductVariant: React.FC<ProductUpdateProps> = ({
                           costPrice: decimal(data.costPrice),
                           id: variantId,
                           priceOverride: decimal(data.priceOverride),
-                          quantity: data.quantity || null,
+                          quantity: parseInt(data.quantity, 0),
                           sku: data.sku,
                           trackInventory: true // FIXME: missing in UI
                         });

src/products/views/ProductVariantCreate.tsx

@@ -66,7 +66,7 @@ export const ProductVariant: React.FC<ProductUpdateProps> = ({ productId }) => {
                       costPrice: decimal(formData.costPrice),
                       priceOverride: decimal(formData.priceOverride),
                       product: productId,
-                      quantity: formData.quantity || null,
+                      quantity: parseInt(formData.quantity, 0),
                       sku: formData.sku,
                       trackInventory: true
                     }