primary keys are non-nullable

Author: eluce2

packages/fmodata/src/orm/field-builders.ts

@@ -36,11 +36,17 @@ export class FieldBuilder<
 
   /**
    * Mark this field as the primary key for the table.
-   * Primary keys are automatically read-only.
+   * Primary keys are automatically read-only and non-nullable.
    */
-  primaryKey(): FieldBuilder<TOutput, TInput, TDbType, true> {
+  primaryKey(): FieldBuilder<
+    NonNullable<TOutput>,
+    NonNullable<TInput>,
+    NonNullable<TDbType>,
+    true
+  > {
     const builder = this._clone() as any;
     builder._primaryKey = true;
+    builder._notNull = true; // Primary keys are automatically non-nullable
     builder._readOnly = true; // Primary keys are automatically read-only
     return builder;
   }

packages/fmodata/tests/typescript.test.ts

@@ -18,7 +18,7 @@
  * helping ensure the API remains ergonomic and type-safe as the library evolves.
  */
 
-import { describe, expect, it, expectTypeOf, beforeEach } from "vitest";
+import { describe, expect, it, expectTypeOf } from "vitest";
 import { z } from "zod/v4";
 import {
   fmTableOccurrence,
@@ -28,6 +28,7 @@ import {
   FMTable,
   getTableColumns,
   eq,
+  type InferTableSchema,
 } from "@proofkit/fmodata";
 import { createMockFetch } from "./utils/mock-fetch";
 import { createMockClient, contacts, users } from "./utils/test-setup";
@@ -554,4 +555,20 @@ describe("fmodata", () => {
       void _typeChecks;
     });
   });
+
+  describe("InferSchemaType", () => {
+    it("Primary key fields should not be nullable in the inferred schema", () => {
+      const specialUsers = fmTableOccurrence("specialUsers", {
+        id: textField().primaryKey(),
+        name: textField(),
+      });
+      type SpecialUserSchema = InferTableSchema<typeof specialUsers>;
+      type IdField = SpecialUserSchema["id"];
+
+      const controlTest: string | null = null;
+
+      // @ts-expect-error - id should not be nullable
+      const idData: IdField = null;
+    });
+  });
 });