fix(products): variant SKU collisions & save-flow error UX

cod-client-astro/locales/ar/products.json

@@ -10,6 +10,9 @@
   "error_delete_has_orders": "لا يمكن حذف منتج لديه سجل طلبات",
   "error_duplicate_sku": "هذا الرمز مستخدم بالفعل",
   "error_insufficient_stock": "لا يمكن أن يقل المخزون عن الصفر",
+  "error_validation": "بعض الحقول غير صالحة",
+  "error_unexpected_id": "حدث خطأ غير متوقع. حاول مرة أخرى — وإذا استمر، أذكر الرقم {id} للدعم.",
+  "error_duplicate_sku_named": "رمز SKU {sku} مستخدم بالفعل في متغير آخر",
   "search_placeholder": "بحث بالاسم أو الرمز...",
   "table": {
     "name": "المنتج",
@@ -118,6 +121,10 @@
     "error_not_found": "المنتج غير موجود",
     "error_load_failed": "فشل تحميل المنتج",
     "error_name_price_required": "الاسم والسعر حقلان مطلوبان",
+    "error_price_integer": "يجب أن يكون السعر رقمًا صحيحًا",
+    "error_duplicate_variant_sku": "صفّان من المتغيرات يستخدمان نفس SKU",
+    "error_variant_row": "تعذر حفظ المتغير {variant}",
+    "partial_save_redirect": "تم حفظ المنتج، لكن فشل أحد المتغيرات: {message}. جارٍ فتح المحرر لتصحيحه.",
     "error_save_failed": "فشل حفظ المنتج",
     "error_required_variant_sku": "كل متغير يتطلب رمزاً",
     "base_price_hint": "السعر الأساسي — يمكن لكل متغير تجاوزه أدناه",

cod-client-astro/locales/en/products.json

@@ -10,6 +10,9 @@
   "error_delete_has_orders": "Cannot delete a product that has order history",
   "error_duplicate_sku": "This SKU is already in use",
   "error_insufficient_stock": "Stock cannot go below zero",
+  "error_validation": "Some fields are invalid",
+  "error_unexpected_id": "An unexpected error occurred. Please try again — if it persists, quote reference {id} to support.",
+  "error_duplicate_sku_named": "SKU {sku} is already used by another variant",
   "search_placeholder": "Search by name, SKU...",
   "table": {
     "name": "Product",
@@ -118,6 +121,10 @@
     "error_not_found": "Product not found",
     "error_load_failed": "Failed to load product",
     "error_name_price_required": "Name and price are required",
+    "error_price_integer": "Price must be a whole number",
+    "error_duplicate_variant_sku": "Two variant rows use the same SKU",
+    "error_variant_row": "Variant {variant} could not be saved",
+    "partial_save_redirect": "Product saved, but a variant failed: {message}. Opening the editor so you can fix it.",
     "error_save_failed": "Failed to save product",
     "error_required_variant_sku": "Every variant needs a SKU",
     "base_price_hint": "Base price — each variant can override this below",

cod-client-astro/locales/fr/products.json

@@ -10,6 +10,9 @@
   "error_delete_has_orders": "Impossible de supprimer un produit ayant un historique de commandes",
   "error_duplicate_sku": "Ce SKU est déjà utilisé",
   "error_insufficient_stock": "Le stock ne peut pas passer sous zéro",
+  "error_validation": "Certains champs sont invalides",
+  "error_unexpected_id": "Une erreur inattendue s'est produite. Réessayez — si elle persiste, communiquez la référence {id} au support.",
+  "error_duplicate_sku_named": "Le SKU {sku} est déjà utilisé par une autre variante",
   "search_placeholder": "Rechercher par nom, SKU...",
   "table": {
     "name": "Produit",
@@ -118,6 +121,10 @@
     "error_not_found": "Produit non trouvé",
     "error_load_failed": "Échec du chargement du produit",
     "error_name_price_required": "Le nom et le prix sont requis",
+    "error_price_integer": "Le prix doit être un nombre entier",
+    "error_duplicate_variant_sku": "Deux lignes de variante utilisent le même SKU",
+    "error_variant_row": "La variante {variant} n'a pas pu être enregistrée",
+    "partial_save_redirect": "Produit enregistré, mais une variante a échoué : {message}. Ouverture de l'éditeur pour corriger.",
     "error_save_failed": "Échec de l'enregistrement du produit",
     "error_required_variant_sku": "Chaque variante nécessite un SKU",
     "base_price_hint": "Prix de base — chaque variante peut l'écraser ci-dessous",

cod-client-astro/src/features/products/components/ProductForm.tsx

@@ -27,6 +27,7 @@ import {
   generateCombinations,
   productErrorMessage,
   toSlug,
+  variantLabel,
 } from "@/features/products/model";
 import type {
   ProductImage,
@@ -232,8 +233,17 @@ export function ProductForm({ productId }: { productId?: string }) {
     if (!name.trim()) next.name = t("form.error_name_price_required");
     if (!price || Number(price) < 0)
       next.price = t("form.error_name_price_required");
+    else if (!Number.isInteger(Number(price)))
+      next.price = t("form.error_price_integer");
     if (hasVariantsSwitch && variantRows.some((row) => !row.sku.trim()))
       next.variantRowsSku = t("form.error_required_variant_sku");
+    if (hasVariantsSwitch) {
+      const skus = variantRows
+        .map((row) => row.sku.trim())
+        .filter(Boolean);
+      if (new Set(skus).size !== skus.length)
+        next.variantRowsSkuDuplicate = t("form.error_duplicate_variant_sku");
+    }
     setErrors(next);
     return Object.keys(next).length === 0;
   }
@@ -242,7 +252,7 @@ export function ProductForm({ productId }: { productId?: string }) {
     if (!validate()) return;
     setBusy(true);
     setMessage(null);
-    try {
+    {
       const apiOptions = apiVariantOptions(variantOptions);
       const hasVariants = apiOptions.length > 0 && variantRows.length > 0;
       const variantsToDelete: string[] = [];
@@ -302,51 +312,82 @@ export function ProductForm({ productId }: { productId?: string }) {
         variantOptions: hasVariants ? apiOptions : null,
       };
 
-      let savedId: string;
-      if (editing && productId) {
-        await updateProduct(productId, data as never);
-        savedId = productId;
-      } else {
-        savedId = (await createProduct(data as never)).data.id;
-      }
+      // Track how far the multi-step save got so the failure message can say
+      // WHAT failed and the retry can never duplicate the product.
+      let savedId: string | null = null;
+      let failedStep: "variants" | "images" | null = null;
+      let failedVariantLabel: string | null = null;
+      try {
+        if (editing && productId) {
+          await updateProduct(productId, data as never);
+          savedId = productId;
+        } else {
+          savedId = (await createProduct(data as never)).data.id;
+        }
 
-      if (hasVariants) {
-        for (const row of variantRows) {
-          if (row.existingId && orphanedIds.has(row.existingId)) continue;
-          const variantData = {
-            variations: row.variations,
-            price: Math.round(Number(row.price) || 0),
-            sku: row.sku.trim(),
-            inventory: Number(row.inventory) || 0,
-            lowStockThreshold: Number(row.lowStockThreshold) || 5,
-            active: row.active,
-            imageId: row.imageId ?? null,
-          };
-          if (row.existingId)
-            await updateVariant(savedId, row.existingId, variantData as never);
-          else await createVariant(savedId, variantData as never);
+        if (hasVariants) {
+          failedStep = "variants";
+          for (const row of variantRows) {
+            if (row.existingId && orphanedIds.has(row.existingId)) continue;
+            const variantData = {
+              variations: row.variations,
+              price: Math.round(Number(row.price) || 0),
+              sku: row.sku.trim(),
+              inventory: Number(row.inventory) || 0,
+              lowStockThreshold: Number(row.lowStockThreshold) || 5,
+              active: row.active,
+              imageId: row.imageId ?? null,
+            };
+            failedVariantLabel = variantLabel(row.variations) || row.sku.trim();
+            if (row.existingId)
+              await updateVariant(savedId, row.existingId, variantData as never);
+            else await createVariant(savedId, variantData as never);
+          }
+          failedVariantLabel = null;
         }
+        failedStep = "images";
+        for (const variantId of variantsToDelete) {
+          await deleteVariant(savedId, variantId);
+        }
+        for (const imageId of deletedImageIds) {
+          await deleteProductImage(savedId, imageId);
+        }
+        for (let i = 0; i < pendingImages.length; i++) {
+          await saveProductImage(savedId, {
+            key: pendingImages[i].key,
+            src: pendingImages[i].url,
+            position: existingImages.length - deletedImageIds.length + i + 1,
+          });
+        }
+        failedStep = null;
+        notify.flashSuccess(t(editing ? "form.success_edit" : "form.success_add"));
+        window.location.assign("/products");
+        return;
+      } catch (cause) {
+        const detail = productErrorMessage(cause, t);
+        let message = detail;
+        if (failedStep === "variants" && failedVariantLabel) {
+          message = `${t("form.error_variant_row")
+            .replace("{variant}", failedVariantLabel)} — ${detail}`;
+        }
+
+        // Partial-save trap: the product row EXISTS (created or updated) but
+        // a later step failed. Retrying "create" would duplicate the product —
+        // send the merchant to the editor instead, where retry = update.
+        if (savedId && !editing) {
+          notify.error(
+            t("form.partial_save_redirect").replace("{message}", detail),
+          );
+          window.location.assign(
+            `/products/${encodeURIComponent(savedId)}/edit`,
+          );
+          return;
+        }
+
+        setMessage(message);
+        notify.error(message);
+        setBusy(false);
       }
-      for (const variantId of variantsToDelete) {
-        await deleteVariant(savedId, variantId);
-      }
-      for (const imageId of deletedImageIds) {
-        await deleteProductImage(savedId, imageId);
-      }
-      for (let i = 0; i < pendingImages.length; i++) {
-        await saveProductImage(savedId, {
-          key: pendingImages[i].key,
-          src: pendingImages[i].url,
-          position: existingImages.length - deletedImageIds.length + i + 1,
-        });
-      }
-      notify.flashSuccess(t(editing ? "form.success_edit" : "form.success_add"));
-      window.location.assign("/products");
-    } catch (cause) {
-      const message = productErrorMessage(cause, t);
-      setMessage(message);
-      notify.error(message);
-      setBusy(false);
     }
   }
 

cod-client-astro/src/features/products/model.ts

@@ -76,12 +76,55 @@ export function parseProductRoute(pathname: string): ProductRoute {
   }
 }
 
+interface ApiLikeError {
+  code?: string;
+  status?: number;
+  context?: Record<string, unknown>;
+}
+
+function asApiError(cause: unknown): ApiLikeError | null {
+  if (!cause || typeof cause !== "object") return null;
+  const candidate = cause as ApiLikeError;
+  return typeof candidate.code === "string" ? candidate : null;
+}
+
 export function productErrorMessage(cause: unknown, t: (key: string) => string) {
-  const code = cause && typeof cause === "object" && "code" in cause ? String(cause.code) : "";
+  const api = asApiError(cause);
+  const code = api?.code ?? "";
+  const context = api?.context;
+
   if (code === "PRODUCT_NOT_FOUND") return t("error_not_found");
   if (code === "PRODUCT_HAS_ORDERS") return t("error_delete_has_orders");
-  if (code === "DUPLICATE_SKU") return t("error_duplicate_sku");
   if (code === "INSUFFICIENT_STOCK") return t("error_insufficient_stock");
+
+  if (code === "DUPLICATE_SKU") {
+    const sku = typeof context?.sku === "string" ? context.sku : null;
+    return sku
+      ? t("error_duplicate_sku_named").replace("{sku}", sku)
+      : t("error_duplicate_sku");
+  }
+
+  if (code === "VALIDATION_FAILED") {
+    const fields = Array.isArray(context?.fields) ? context!.fields : [];
+    const lines = fields
+      .map((field) => {
+        const entry = field as { path?: string; message?: string };
+        return entry.path ? `${entry.path}: ${entry.message ?? ""}` : entry.message ?? "";
+      })
+      .filter(Boolean);
+    return lines.length
+      ? `${t("error_validation")} — ${lines.join(" · ")}`
+      : t("error_validation");
+  }
+
+  if (code === "INTERNAL_SERVER_ERROR" || (api?.status ?? 0) >= 500) {
+    const requestId =
+      typeof context?.requestId === "string" ? context.requestId : null;
+    return requestId
+      ? t("error_unexpected_id").replace("{id}", requestId)
+      : t("error_generic");
+  }
+
   return t("error_generic");
 }
 

cod-server/src/endpoints/variants/CONTEXT.md

@@ -59,7 +59,7 @@ Terms owned by neighboring contexts — use them, don't redefine them here:
 
 **No blueprint police**: Creating `{"Material": "Gold"}` on a product whose declared options only list Color succeeds silently — drift between options and real variants is possible.
 
-**SKU collisions crash late**: Duplicate SKUs surface as raw database constraint errors rather than friendly conflicts, because uniqueness is delegated entirely to the schema.
+**SKU collisions fail friendly**: Duplicate SKUs are caught by a pre-check (and a defensive constraint mapping for races) and rejected as a 409 Conflict carrying the offending SKU — the same treatment product creation gets.
 
 **Parent existence is assumed**: Creating a variant against a nonexistent product fails at the foreign-key level, not with a clean not-found message.
 

cod-server/src/endpoints/variants/queries.ts

@@ -1,5 +1,80 @@
 /**
  * Re-exported from cod-shared/queries/variants so the dashboard can consume
  * the same read functions directly from D1.
+ *
+ * createVariant/updateVariant wrappers stay here because they raise
+ * BusinessLogicError: the SKU uniqueness pre-check turns a raw DB constraint
+ * crash (HTTP 500) into a friendly 409 DUPLICATE_SKU carrying the SKU.
  */
+import { eq, and, ne } from "drizzle-orm";
+import { productVariants } from "@/db/schema";
+import type { AppDb } from "@/db";
+import { ConflictError } from "@/lib/errors/classes";
+import { ERROR_CODES } from "../../../../cod-shared/errors/codes";
+import * as shared from "../../../../cod-shared/queries/variants";
+
 export * from "../../../../cod-shared/queries/variants";
+
+type CreateVariantData = Parameters<typeof shared.createVariant>[2];
+type UpdateVariantData = Parameters<typeof shared.updateVariant>[2];
+
+function isSkuUniqueViolation(err: unknown): boolean {
+  return (
+    err instanceof Error &&
+    /UNIQUE constraint failed: product_variants\.sku/i.test(err.message)
+  );
+}
+
+function duplicateSkuError(sku: string) {
+  return new ConflictError(
+    `SKU "${sku}" is already used by another variant`,
+    ERROR_CODES.DUPLICATE_SKU,
+    { sku },
+  );
+}
+
+async function assertSkuAvailable(
+  db: AppDb,
+  sku: string,
+  excludeVariantId: string | null,
+) {
+  const clash = await db
+    .select({ id: productVariants.id, productId: productVariants.productId })
+    .from(productVariants)
+    .where(
+      excludeVariantId
+        ? and(eq(productVariants.sku, sku), ne(productVariants.id, excludeVariantId))
+        : eq(productVariants.sku, sku),
+    )
+    .get();
+  if (clash) throw duplicateSkuError(sku);
+}
+
+export async function createVariant(
+  db: AppDb,
+  productId: string,
+  data: CreateVariantData,
+) {
+  if (data.sku) await assertSkuAvailable(db, data.sku, null);
+  try {
+    return await shared.createVariant(db, productId, data);
+  } catch (err) {
+    // Race: a concurrent writer took the SKU between check and insert.
+    if (isSkuUniqueViolation(err)) throw duplicateSkuError(data.sku);
+    throw err;
+  }
+}
+
+export async function updateVariant(
+  db: AppDb,
+  variantId: string,
+  data: UpdateVariantData,
+) {
+  if (data.sku) await assertSkuAvailable(db, data.sku, variantId);
+  try {
+    return await shared.updateVariant(db, variantId, data);
+  } catch (err) {
+    if (data.sku && isSkuUniqueViolation(err)) throw duplicateSkuError(data.sku);
+    throw err;
+  }
+}