fix: incorrect policy injection for post-update rules with deep member access

Fixes #1648

Author: ymc9

packages/schema/src/plugins/enhancer/policy/expression-writer.ts

@@ -378,17 +378,9 @@ export class ExpressionWriter {
             operator = this.negateOperator(operator);
         }
 
-        if (this.isFutureMemberAccess(fieldAccess)) {
-            // future().field should be treated as the "field" directly, so we
-            // strip 'future().' and synthesize a reference expr
-            fieldAccess = {
-                $type: ReferenceExpr,
-                $container: fieldAccess.$container,
-                target: fieldAccess.member,
-                $resolvedType: fieldAccess.$resolvedType,
-                $future: true,
-            } as unknown as ReferenceExpr;
-        }
+        // future()...field should be treated as the "field" directly, so we
+        // strip 'future().' and synthesize a reference/member-access expr
+        fieldAccess = this.stripFutureCall(fieldAccess);
 
         // guard member access of `auth()` with null check
         if (this.isAuthOrAuthMemberAccess(operand) && !fieldAccess.$resolvedType?.nullable) {
@@ -472,6 +464,39 @@ export class ExpressionWriter {
         );
     }
 
+    private stripFutureCall(fieldAccess: Expression) {
+        if (!this.isFutureMemberAccess(fieldAccess)) {
+            return fieldAccess;
+        }
+
+        const memberAccessStack: MemberAccessExpr[] = [];
+        let current: Expression = fieldAccess;
+        while (isMemberAccessExpr(current)) {
+            memberAccessStack.push(current);
+            current = current.operand;
+        }
+
+        const top = memberAccessStack.pop()!;
+
+        // turn the inner-most member access into a reference expr (strip 'future()')
+        let result: Expression = {
+            $type: ReferenceExpr,
+            $container: top.$container,
+            target: top.member,
+            $resolvedType: top.$resolvedType,
+            args: [],
+        } satisfies ReferenceExpr;
+
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        (result as any).$future = true;
+
+        // re-apply member accesses
+        for (const memberAccess of memberAccessStack.reverse()) {
+            result = { ...memberAccess, operand: result };
+        }
+        return result;
+    }
+
     private isFutureMemberAccess(expr: Expression): expr is MemberAccessExpr {
         if (!isMemberAccessExpr(expr)) {
             return false;

tests/integration/tests/enhancements/with-policy/post-update.test.ts

@@ -552,4 +552,47 @@ describe('With Policy: post update', () => {
             expect.arrayContaining([expect.objectContaining({ value: 3 }), expect.objectContaining({ value: 4 })])
         );
     });
+
+    it('deep member access', async () => {
+        const { enhance } = await loadSchema(
+            `
+        model M1 {
+            id Int @id @default(autoincrement())
+            m2 M2?
+            v1 Int
+            @@allow('all', true)
+            @@deny('update', future().m2.m3.v3 > 1)
+        }
+
+        model M2 {
+            id Int @id @default(autoincrement())
+            m1 M1 @relation(fields: [m1Id], references:[id])
+            m1Id Int @unique
+            m3 M3?
+            @@allow('all', true)
+        }
+
+        model M3 {
+            id Int @id @default(autoincrement())
+            v3 Int
+            m2 M2 @relation(fields: [m2Id], references:[id])
+            m2Id Int @unique
+            @@allow('all', true)
+        }
+        `
+        );
+
+        const db = enhance();
+
+        await db.m1.create({
+            data: { id: 1, v1: 1, m2: { create: { id: 1, m3: { create: { id: 1, v3: 1 } } } } },
+        });
+
+        await db.m1.create({
+            data: { id: 2, v1: 2, m2: { create: { id: 2, m3: { create: { id: 2, v3: 2 } } } } },
+        });
+
+        await expect(db.m1.update({ where: { id: 1 }, data: { v1: 2 } })).toResolveTruthy();
+        await expect(db.m1.update({ where: { id: 2 }, data: { v1: 3 } })).toBeRejectedByPolicy();
+    });
 });

tests/regression/tests/issue-1648.test.ts

@@ -0,0 +1,43 @@
+import { loadSchema } from '@zenstackhq/testtools';
+describe('issue 1648', () => {
+    it('regression', async () => {
+        const { prisma, enhance } = await loadSchema(
+            `
+            model User {
+                id      Int      @id @default(autoincrement())
+                profile Profile?
+                posts   Post[]
+            }
+
+            model Profile {
+                id     Int  @id @default(autoincrement())
+                someText String
+                user   User @relation(fields: [userId], references: [id])
+                userId Int  @unique
+            }
+
+            model Post {
+                id     Int    @id @default(autoincrement())
+                title  String
+
+                userId Int
+                user   User   @relation(fields: [userId], references: [id])
+
+                // this will always be true, even if the someText field is "canUpdate"
+                @@deny("update", future().user.profile.someText != "canUpdate")
+
+                @@allow("all", true)
+            }
+            `
+        );
+
+        await prisma.user.create({ data: { id: 1, profile: { create: { someText: 'canUpdate' } } } });
+        await prisma.user.create({ data: { id: 2, profile: { create: { someText: 'nothing' } } } });
+        await prisma.post.create({ data: { id: 1, title: 'Post1', userId: 1 } });
+        await prisma.post.create({ data: { id: 2, title: 'Post2', userId: 2 } });
+
+        const db = enhance();
+        await expect(db.post.update({ where: { id: 1 }, data: { title: 'Post1-1' } })).toResolveTruthy();
+        await expect(db.post.update({ where: { id: 2 }, data: { title: 'Post2-2' } })).toBeRejectedByPolicy();
+    });
+});