Fix strict select subset typing under TS6

packages/orm/src/client/crud-types.ts

@@ -1315,8 +1315,20 @@ export type Subset<T, U> = {
     [key in keyof T]: key extends keyof U ? T[key] : never;
 };
 
+type NoExtraKeys<T, Shape> = T extends object ? T & { [K in Exclude<keyof T, keyof Shape>]: never } : T;
+
+type PreserveNullish<T, Strict> = Strict | Extract<T, null | undefined>;
+
+type StrictArgProperty<T, U, Key extends PropertyKey> = Key extends keyof U
+    ? PreserveNullish<T, NoExtraKeys<NonNullable<T>, NonNullable<U[Key]>>>
+    : T;
+
 export type SelectSubset<T, U> = {
-    [key in keyof T]: key extends keyof U ? T[key] : never;
+    [key in keyof T]: key extends keyof U
+        ? key extends 'select' | 'include' | 'omit'
+            ? StrictArgProperty<T[key], U, key>
+            : T[key]
+        : never;
 } & (T extends { select: any; include: any }
     ? 'Please either choose `select` or `include`.'
     : T extends { select: any; omit: any }

tests/e2e/orm/client-api/slicing.test.ts

@@ -216,13 +216,15 @@ describe('Query slicing tests', () => {
             // Profile is excluded, so selecting it should cause type error
             await expect(
                 db.user.findMany({
+                    // @ts-expect-error Profile is excluded by slicing
                     select: { id: true, profile: true },
                 }),
             ).toBeRejectedByValidation(['"profile"', '"select"']);
 
             // Comment is excluded, so selecting it should cause type error
             await expect(
                 db.post.findMany({
+                    // @ts-expect-error Comment is excluded by slicing
                     select: { id: true, comments: true },
                 }),
             ).toBeRejectedByValidation(['"comments"', '"select"']);
@@ -295,13 +297,15 @@ describe('Query slicing tests', () => {
             // Profile is not included, so selecting it should cause type error
             await expect(
                 db.user.findMany({
+                    // @ts-expect-error Profile is not included by slicing
                     select: { id: true, profile: true },
                 }),
             ).toBeRejectedByValidation(['"profile"', '"select"']);
 
             // Comment is not included, so selecting it should cause type error
             await expect(
                 db.post.findMany({
+                    // @ts-expect-error Comment is not included by slicing
                     select: { id: true, comments: true },
                 }),
             ).toBeRejectedByValidation(['"comments"', '"select"']);

tests/e2e/orm/client-api/unsupported.test.ts

@@ -205,6 +205,7 @@ describe('Unsupported field exclusion - Zod runtime validation', () => {
         it('rejects Unsupported fields in select', async () => {
             // valid call
             await db.item.findMany({ select: { id: true, name: true } });
+            // @ts-expect-error data (Unsupported) should not be in select
             await expect(db.item.findMany({ select: { data: true } })).toBeRejectedByValidation();
         });
 

tests/e2e/orm/schemas/typing/typecheck.ts

@@ -74,6 +74,16 @@ async function find() {
     });
     console.log(user2.email);
     console.log(user2.profile?.age);
+    // @ts-expect-error name was not selected
+    console.log(user2.name);
+
+    await client.user.findMany({
+        select: {
+            email: true,
+            // @ts-expect-error invalid select field
+            missingField: true,
+        },
+    });
 
     await client.user.findUnique({
         // @ts-expect-error expect unique filter