Filter unit dropdown by product allowed-unit categories

Adds a UnitCategoryFlags column to Product, FamilyProduct, and
FamilyProductOverride so each product can advertise which unit categories
it is typically packaged by (e.g. flour: Weight | Volume). The product
endpoints round-trip the flag, search projects the effective value with
the override applied, and the frontend QuantityInput soft-filters its
dropdown by the selected product's flag, with a "show all units" escape
hatch for ad-hoc overrides.

No backend rejection on a unit outside the allowed set — the flag is
purely a hint. Default value is None (no filter), so existing data is
unaffected.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/backend/YesChef.Api.IntegrationTests/Features/ProductEndpointsTests.cs

@@ -247,6 +247,115 @@ public class ProductEndpointsTests : AuthenticatedIntegrationTest
         await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.NotFound);
     }
 
+    [Test]
+    public async Task Create_family_product_persists_allowed_unit_categories()
+    {
+        var response = await Client.PostAsJsonAsync("/api/products",
+            new ProductEndpoints.CreateProductRequest("House Flour", null, null,
+                UnitCategoryFlags.Weight | UnitCategoryFlags.Volume));
+
+        await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.Created);
+        var stored = await UseDbAsync(db => db.FamilyProducts.SingleAsync());
+        await Assert.That(stored.AllowedUnitCategories)
+            .IsEqualTo(UnitCategoryFlags.Weight | UnitCategoryFlags.Volume);
+    }
+
+    [Test]
+    public async Task Update_family_product_changes_allowed_unit_categories()
+    {
+        var familyId = await GetFamilyIdAsync();
+        var product = await UseDbAsync(async db =>
+        {
+            var p = new FamilyProduct
+            {
+                FamilyId = familyId,
+                Name = "Flour",
+                AllowedUnitCategories = UnitCategoryFlags.Weight,
+            };
+            db.FamilyProducts.Add(p);
+            await db.SaveChangesAsync();
+            return p;
+        });
+
+        var response = await Client.PutAsJsonAsync($"/api/products/family/{product.Id}",
+            new ProductEndpoints.UpdateProductRequest(null, null, null,
+                UnitCategoryFlags.Weight | UnitCategoryFlags.Volume));
+
+        await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.OK);
+        var stored = await UseDbAsync(db => db.FamilyProducts.SingleAsync());
+        await Assert.That(stored.AllowedUnitCategories)
+            .IsEqualTo(UnitCategoryFlags.Weight | UnitCategoryFlags.Volume);
+    }
+
+    [Test]
+    public async Task Update_global_product_writes_allowed_unit_categories_to_override()
+    {
+        var apples = await UseDbAsync(async db =>
+        {
+            var p = new Product
+            {
+                Name = "Milk",
+                AllowedUnitCategories = UnitCategoryFlags.Volume,
+            };
+            db.Products.Add(p);
+            await db.SaveChangesAsync();
+            return p;
+        });
+
+        var response = await Client.PutAsJsonAsync($"/api/products/global/{apples.Id}",
+            new ProductEndpoints.UpdateProductRequest(null, null, null,
+                UnitCategoryFlags.Volume | UnitCategoryFlags.Packaging));
+
+        await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.OK);
+        var ovr = await UseDbAsync(db => db.FamilyProductOverrides.SingleAsync());
+        await Assert.That(ovr.AllowedUnitCategories)
+            .IsEqualTo(UnitCategoryFlags.Volume | UnitCategoryFlags.Packaging);
+
+        // The global row remains unchanged.
+        var global = await UseDbAsync(db => db.Products.SingleAsync(p => p.Id == apples.Id));
+        await Assert.That(global.AllowedUnitCategories).IsEqualTo(UnitCategoryFlags.Volume);
+    }
+
+    [Test]
+    public async Task Search_projects_effective_allowed_unit_categories()
+    {
+        var familyId = await GetFamilyIdAsync();
+        await UseDbAsync(async db =>
+        {
+            db.Products.Add(new Product { Name = "Milk", AllowedUnitCategories = UnitCategoryFlags.Volume });
+            db.Products.Add(new Product { Name = "Eggs", AllowedUnitCategories = UnitCategoryFlags.Count });
+            db.FamilyProducts.Add(new FamilyProduct
+            {
+                FamilyId = familyId,
+                Name = "House Flour",
+                AllowedUnitCategories = UnitCategoryFlags.Weight,
+            });
+            await db.SaveChangesAsync();
+
+            // Override Eggs to widen to Count | Packaging for this family.
+            var eggs = db.Products.Single(p => p.Name == "Eggs");
+            db.FamilyProductOverrides.Add(new FamilyProductOverride
+            {
+                FamilyId = familyId,
+                ProductId = eggs.Id,
+                AllowedUnitCategories = UnitCategoryFlags.Count | UnitCategoryFlags.Packaging,
+            });
+            await db.SaveChangesAsync();
+        });
+
+        var results = await Client.GetFromJsonAsync<List<ProductEndpoints.ProductDto>>("/api/products?q=");
+
+        var milk = results!.Single(r => r.Name == "Milk");
+        await Assert.That(milk.AllowedUnitCategories).IsEqualTo(UnitCategoryFlags.Volume);
+
+        var eggs = results.Single(r => r.Name == "Eggs");
+        await Assert.That(eggs.AllowedUnitCategories)
+            .IsEqualTo(UnitCategoryFlags.Count | UnitCategoryFlags.Packaging);
+
+        var flour = results.Single(r => r.Name == "House Flour");
+        await Assert.That(flour.AllowedUnitCategories).IsEqualTo(UnitCategoryFlags.Weight);
+    }
+
     [Test]
     public async Task Endpoints_require_authentication()
     {

src/backend/YesChef.Api/Data/YesChefDb.cs

@@ -140,6 +140,7 @@ public class YesChefDb(DbContextOptions<YesChefDb> options) : DbContext(options)
             e.Property(p => p.Name).HasMaxLength(200);
             e.Property(p => p.Brand).HasMaxLength(200);
             e.Property(p => p.Notes).HasMaxLength(1000);
+            e.Property(p => p.AllowedUnitCategories).HasConversion<int>();
             e.HasIndex(p => p.Name).IsUnique();
         });
 
@@ -148,6 +149,7 @@ public class YesChefDb(DbContextOptions<YesChefDb> options) : DbContext(options)
             e.Property(p => p.Name).HasMaxLength(200);
             e.Property(p => p.Brand).HasMaxLength(200);
             e.Property(p => p.Notes).HasMaxLength(1000);
+            e.Property(p => p.AllowedUnitCategories).HasConversion<int>();
             e.HasOne(p => p.Family).WithMany().HasForeignKey(p => p.FamilyId).OnDelete(DeleteBehavior.Cascade);
             e.HasIndex(p => new { p.FamilyId, p.Name }).IsUnique();
         });
@@ -158,6 +160,7 @@ public class YesChefDb(DbContextOptions<YesChefDb> options) : DbContext(options)
             e.Property(o => o.Name).HasMaxLength(200);
             e.Property(o => o.Brand).HasMaxLength(200);
             e.Property(o => o.Notes).HasMaxLength(1000);
+            e.Property(o => o.AllowedUnitCategories).HasConversion<int?>();
             e.HasOne(o => o.Family).WithMany().HasForeignKey(o => o.FamilyId).OnDelete(DeleteBehavior.Cascade);
             e.HasOne(o => o.Product).WithMany().HasForeignKey(o => o.ProductId).OnDelete(DeleteBehavior.Cascade);
         });

src/backend/YesChef.Api/Entities/FamilyProduct.cs

@@ -12,5 +12,6 @@ public class FamilyProduct
     public required string Name { get; set; }
     public string? Brand { get; set; }
     public string? Notes { get; set; }
+    public UnitCategoryFlags AllowedUnitCategories { get; set; }
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
 }

src/backend/YesChef.Api/Entities/FamilyProductOverride.cs

@@ -15,5 +15,8 @@ public class FamilyProductOverride
     public string? Name { get; set; }
     public string? Brand { get; set; }
     public string? Notes { get; set; }
+    // Nullable so "inherit global" (null) is distinguishable from
+    // "explicitly None / any unit" (UnitCategoryFlags.None).
+    public UnitCategoryFlags? AllowedUnitCategories { get; set; }
     public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
 }

src/backend/YesChef.Api/Entities/Product.cs

@@ -11,5 +11,8 @@ public class Product
     public required string Name { get; set; }
     public string? Brand { get; set; }
     public string? Notes { get; set; }
+    // None = "any unit". Non-zero narrows the unit-dropdown suggestions to the
+    // flagged categories. Families can replace this with FamilyProductOverride.
+    public UnitCategoryFlags AllowedUnitCategories { get; set; }
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
 }

src/backend/YesChef.Api/Entities/UnitCategoryFlags.cs

@@ -0,0 +1,29 @@
+namespace YesChef.Api.Entities;
+
+/// <summary>
+/// Multi-select sibling of <see cref="UnitCategory"/>. A product can be
+/// "typically packaged" by one or more categories (e.g. flour: Weight | Volume),
+/// and the unit dropdown filters its suggestions accordingly. Stored as a
+/// 32-bit integer so families can OR in additional categories over time.
+/// </summary>
+[System.Flags]
+public enum UnitCategoryFlags
+{
+    None = 0,
+    Count = 1 << 0,
+    Weight = 1 << 1,
+    Volume = 1 << 2,
+    Packaging = 1 << 3,
+}
+
+public static class UnitCategoryFlagsExtensions
+{
+    public static UnitCategoryFlags ToFlag(this UnitCategory c) => c switch
+    {
+        UnitCategory.Count => UnitCategoryFlags.Count,
+        UnitCategory.Weight => UnitCategoryFlags.Weight,
+        UnitCategory.Volume => UnitCategoryFlags.Volume,
+        UnitCategory.Packaging => UnitCategoryFlags.Packaging,
+        _ => UnitCategoryFlags.None,
+    };
+}

src/backend/YesChef.Api/Features/Products/ProductEndpoints.cs

@@ -18,10 +18,11 @@ public static class ProductEndpoints
         string Name,
         string? Brand,
         string? Notes,
-        bool IsOverridden);
+        bool IsOverridden,
+        UnitCategoryFlags AllowedUnitCategories);
 
-    public record CreateProductRequest(string Name, string? Brand, string? Notes);
+    public record CreateProductRequest(string Name, string? Brand, string? Notes, UnitCategoryFlags AllowedUnitCategories = UnitCategoryFlags.None);
-    public record UpdateProductRequest(string? Name, string? Brand, string? Notes);
+    public record UpdateProductRequest(string? Name, string? Brand, string? Notes, UnitCategoryFlags? AllowedUnitCategories = null);
 
     private const int SearchResultLimit = 50;
 
@@ -54,9 +55,11 @@ public static class ProductEndpoints
                     GlobalName = p.Name,
                     GlobalBrand = p.Brand,
                     GlobalNotes = p.Notes,
+                    GlobalAllowedUnitCategories = p.AllowedUnitCategories,
                     OverrideName = o != null ? o.Name : null,
                     OverrideBrand = o != null ? o.Brand : null,
                     OverrideNotes = o != null ? o.Notes : null,
+                    OverrideAllowedUnitCategories = o != null ? o.AllowedUnitCategories : null,
                     HasOverride = o != null,
                 })
                 .Take(SearchResultLimit)
@@ -82,11 +85,12 @@ public static class ProductEndpoints
                     name,
                     r.OverrideBrand ?? r.GlobalBrand,
                     r.OverrideNotes ?? r.GlobalNotes,
-                    r.HasOverride);
+                    r.HasOverride,
+                    r.OverrideAllowedUnitCategories ?? r.GlobalAllowedUnitCategories);
             }).Where(d => d is not null).Cast<ProductDto>();
 
             var familyDtos = familyRows.Select(p =>
-                new ProductDto(p.Id, ProductKind.Family, p.Name, p.Brand, p.Notes, IsOverridden: false));
+                new ProductDto(p.Id, ProductKind.Family, p.Name, p.Brand, p.Notes, IsOverridden: false, p.AllowedUnitCategories));
 
             var results = globalDtos.Concat(familyDtos)
                 .OrderBy(d => d.Name, StringComparer.OrdinalIgnoreCase)
@@ -114,6 +118,7 @@ public static class ProductEndpoints
                 Name = name,
                 Brand = request.Brand,
                 Notes = request.Notes,
+                AllowedUnitCategories = request.AllowedUnitCategories,
             };
             db.FamilyProducts.Add(product);
             await db.SaveChangesAsync();
@@ -142,6 +147,7 @@ public static class ProductEndpoints
             }
             product.Brand = request.Brand;
             product.Notes = request.Notes;
+            if (request.AllowedUnitCategories is { } cats) product.AllowedUnitCategories = cats;
             await db.SaveChangesAsync();
 
             return Results.Ok(ToDto(product));
@@ -174,6 +180,10 @@ public static class ProductEndpoints
             ovr.Name = trimmedName;
             ovr.Brand = request.Brand;
             ovr.Notes = request.Notes;
+            // null in the request leaves the override's value alone (which may
+            // itself be null, i.e. "inherit global"). Pass an explicit value to
+            // either narrow categories or restore "any" (UnitCategoryFlags.None).
+            if (request.AllowedUnitCategories is { } cats) ovr.AllowedUnitCategories = cats;
             ovr.UpdatedAt = DateTime.UtcNow;
             await db.SaveChangesAsync();
 
@@ -183,12 +193,13 @@ public static class ProductEndpoints
                 ovr.Name ?? product.Name,
                 ovr.Brand ?? product.Brand,
                 ovr.Notes ?? product.Notes,
-                IsOverridden: true));
+                IsOverridden: true,
+                ovr.AllowedUnitCategories ?? product.AllowedUnitCategories));
         });
 
         return group;
     }
 
     private static ProductDto ToDto(FamilyProduct p) =>
-        new(p.Id, ProductKind.Family, p.Name, p.Brand, p.Notes, IsOverridden: false);
+        new(p.Id, ProductKind.Family, p.Name, p.Brand, p.Notes, IsOverridden: false, p.AllowedUnitCategories);
 }

src/backend/YesChef.Api/Migrations/20260514030907_AddProductAllowedUnitCategories.cs

@@ -0,0 +1,50 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace YesChef.Api.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddProductAllowedUnitCategories : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "AllowedUnitCategories",
+                table: "Products",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.AddColumn<int>(
+                name: "AllowedUnitCategories",
+                table: "FamilyProducts",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.AddColumn<int>(
+                name: "AllowedUnitCategories",
+                table: "FamilyProductOverrides",
+                type: "integer",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "AllowedUnitCategories",
+                table: "Products");
+
+            migrationBuilder.DropColumn(
+                name: "AllowedUnitCategories",
+                table: "FamilyProducts");
+
+            migrationBuilder.DropColumn(
+                name: "AllowedUnitCategories",
+                table: "FamilyProductOverrides");
+        }
+    }
+}

src/backend/YesChef.Api/Migrations/YesChefDbModelSnapshot.cs

@@ -80,6 +80,9 @@ namespace YesChef.Api.Migrations
 
                     NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
 
+                    b.Property<int>("AllowedUnitCategories")
+                        .HasColumnType("integer");
+
                     b.Property<string>("Brand")
                         .HasMaxLength(200)
                         .HasColumnType("character varying(200)");
@@ -115,6 +118,9 @@ namespace YesChef.Api.Migrations
                     b.Property<int>("ProductId")
                         .HasColumnType("integer");
 
+                    b.Property<int?>("AllowedUnitCategories")
+                        .HasColumnType("integer");
+
                     b.Property<string>("Brand")
                         .HasMaxLength(200)
                         .HasColumnType("character varying(200)");
@@ -273,6 +279,9 @@ namespace YesChef.Api.Migrations
 
                     NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
 
+                    b.Property<int>("AllowedUnitCategories")
+                        .HasColumnType("integer");
+
                     b.Property<string>("Brand")
                         .HasMaxLength(200)
                         .HasColumnType("character varying(200)");

src/frontend/src/lib/ProductTypeahead.svelte

@@ -1,4 +1,14 @@
 <script lang="ts" module>
+	// Bitfield matching backend UnitCategoryFlags. Stored as an int on the wire.
+	export const UnitCategoryFlag = {
+		None: 0,
+		Count: 1,
+		Weight: 2,
+		Volume: 4,
+		Packaging: 8,
+	} as const;
+	export type UnitCategoryFlag = typeof UnitCategoryFlag[keyof typeof UnitCategoryFlag];
+
 	export interface ProductSuggestion {
 		id: number;
 		kind: 'Global' | 'Family';
@@ -6,6 +16,7 @@
 		brand: string | null;
 		notes: string | null;
 		isOverridden: boolean;
+		allowedUnitCategories: number;
 	}
 </script>
 

src/frontend/src/lib/QuantityInput.svelte

@@ -7,17 +7,20 @@
 </script>
 
 <script lang="ts">
-	import { units } from '$lib/units.svelte';
+	import { units, type UnitCategory } from '$lib/units.svelte';
 
 	interface Props {
 		value: QuantityValue;
 		ariaLabel?: string;
+		// When non-zero, soft-filters the unit dropdown to units whose category
+		// is one of the flagged categories. Users can still expand to all units
+		// via the "show all" link. 0 (None) = no filter applied.
+		allowedUnitCategories?: number;
 	}
 
-	let { value = $bindable(), ariaLabel = 'Quantity' }: Props = $props();
+	let { value = $bindable(), ariaLabel = 'Quantity', allowedUnitCategories = 0 }: Props = $props();
+	let showAll = $state(false);
 
-	// The unit dropdown carries a composite id "kind:id" so we can route to
-	// the right FK column on the server. "" = no unit selected.
 	const composite = $derived.by(() => {
 		if (value.unitOfMeasureId !== null) return `Global:${value.unitOfMeasureId}`;
 		if (value.familyUnitOfMeasureId !== null) return `Family:${value.familyUnitOfMeasureId}`;
@@ -47,11 +50,32 @@
 		value.quantity = raw === '' ? null : Number(raw);
 	}
 
+	const categoryBit: Record<UnitCategory, number> = {
+		Count: 1, Weight: 2, Volume: 4, Packaging: 8,
+	};
+
 	const sorted = $derived(
 		[...units.all].sort((a, b) => a.sortOrder - b.sortOrder || a.singularName.localeCompare(b.singularName))
 	);
+
+	// If the filter mask is non-zero and showAll isn't on, keep only matching
+	// units — plus the currently-selected one so the dropdown can render it
+	// even if the product was changed to one with a tighter filter.
+	const visible = $derived.by(() => {
+		const mask = allowedUnitCategories;
+		if (mask === 0 || showAll) return sorted;
+		const selectedId = value.unitOfMeasureId ?? value.familyUnitOfMeasureId;
+		const selectedKind = value.unitOfMeasureId !== null ? 'Global' : 'Family';
+		return sorted.filter((u) => {
+			if ((categoryBit[u.category] & mask) !== 0) return true;
+			return selectedId !== null && u.id === selectedId && u.kind === selectedKind;
+		});
+	});
+
+	const filterIsActive = $derived(allowedUnitCategories !== 0 && !showAll && visible.length !== sorted.length);
 </script>
 
+<div class="flex flex-col gap-0.5">
 	<div class="flex gap-1">
 		<input
 			type="number"
@@ -71,8 +95,14 @@
 			class="w-24 rounded-lg border border-gray-300 px-1 py-2 text-sm focus:border-primary focus:outline-none"
 		>
 			<option value="">unit</option>
-		{#each sorted as unit}
+			{#each visible as unit}
 				<option value="{unit.kind}:{unit.id}">{unit.abbreviation}</option>
 			{/each}
 		</select>
 	</div>
+	{#if filterIsActive}
+		<button type="button" onclick={() => (showAll = true)} class="text-[10px] text-gray-400 hover:text-primary">
+			show all units
+		</button>
+	{/if}
+</div>

src/frontend/src/routes/lists/[id]/+page.svelte

@@ -53,6 +53,7 @@
 	let newItemQuantity = $state<QuantityValue>({ quantity: null, unitOfMeasureId: null, familyUnitOfMeasureId: null });
 	let newItemIsApproximate = $state(false);
 	let newItemQuantityNote = $state('');
+	let newItemAllowedUnitCategories = $state(0);
 	let loading = $state(true);
 	let connection: HubConnection | null = null;
 
@@ -190,6 +191,7 @@
 		newItemQuantity = { quantity: null, unitOfMeasureId: null, familyUnitOfMeasureId: null };
 		newItemIsApproximate = false;
 		newItemQuantityNote = '';
+		newItemAllowedUnitCategories = 0;
 	}
 
 	function toggleApproximateNewItem() {
@@ -205,12 +207,15 @@
 		if (product === null) {
 			newItemProductId = null;
 			newItemFamilyProductId = null;
+			newItemAllowedUnitCategories = 0;
 		} else if (product.kind === 'Global') {
 			newItemProductId = product.id;
 			newItemFamilyProductId = null;
+			newItemAllowedUnitCategories = product.allowedUnitCategories;
 		} else {
 			newItemProductId = null;
 			newItemFamilyProductId = product.id;
+			newItemAllowedUnitCategories = product.allowedUnitCategories;
 		}
 	}
 
@@ -278,7 +283,10 @@
 						class="w-36 rounded-lg border border-gray-300 px-2 py-2.5 text-sm focus:border-primary focus:outline-none"
 					/>
 				{:else}
-					<QuantityInput bind:value={newItemQuantity} />
+					<QuantityInput
+						bind:value={newItemQuantity}
+						allowedUnitCategories={newItemAllowedUnitCategories}
+					/>
 				{/if}
 				<div class="min-w-0 flex-1">
 					<ProductTypeahead

src/frontend/src/routes/recipes/new/+page.svelte

@@ -11,6 +11,7 @@
 		quantityNote: string;
 		productId: number | null;
 		familyProductId: number | null;
+		allowedUnitCategories: number;
 	}
 
 	let title = $state('');
@@ -28,6 +29,7 @@
 			quantityNote: '',
 			productId: null,
 			familyProductId: null,
+			allowedUnitCategories: 0,
 		};
 	}
 
@@ -54,12 +56,15 @@
 		if (product === null) {
 			next.productId = null;
 			next.familyProductId = null;
+			next.allowedUnitCategories = 0;
 		} else if (product.kind === 'Global') {
 			next.productId = product.id;
 			next.familyProductId = null;
+			next.allowedUnitCategories = product.allowedUnitCategories;
 		} else {
 			next.productId = null;
 			next.familyProductId = product.id;
+			next.allowedUnitCategories = product.allowedUnitCategories;
 		}
 	}
 
@@ -143,7 +148,10 @@
 								class="w-44 rounded-lg border border-gray-300 px-2 py-2 text-sm focus:border-primary focus:outline-none"
 							/>
 						{:else}
-							<QuantityInput bind:value={ingredient.quantity} />
+							<QuantityInput
+								bind:value={ingredient.quantity}
+								allowedUnitCategories={ingredient.allowedUnitCategories}
+							/>
 						{/if}
 						<div class="flex-1">
 							<ProductTypeahead