fix: resolve member access expr only in the context of operand type

packages/schema/src/language-server/zmodel-linker.ts

@@ -92,9 +92,10 @@ export class ZModelLinker extends DefaultLinker {
         container: AstNode,
         property: string,
         document: LangiumDocument,
-        extraScopes: ScopeProvider[]
+        extraScopes: ScopeProvider[],
+        onlyFromExtraScopes = false
     ) {
-        if (!this.resolveFromScopeProviders(container, property, document, extraScopes)) {
+        if (!this.resolveFromScopeProviders(container, property, document, extraScopes) && !onlyFromExtraScopes) {
             // eslint-disable-next-line @typescript-eslint/no-explicit-any
             const reference: Reference<AstNode> = (container as any)[property];
             this.doLink({ reference, container, property }, document);
@@ -327,12 +328,11 @@ export class ZModelLinker extends DefaultLinker {
         if (operandResolved && !operandResolved.array && isDataModel(operandResolved.decl)) {
             const modelDecl = operandResolved.decl as DataModel;
             const provider = (name: string) => modelDecl.$resolvedFields.find((f) => f.name === name);
-            extraScopes = [provider, ...extraScopes];
-        }
-
-        this.linkReference(node, 'member', document, extraScopes);
-        if (node.member.ref) {
-            this.resolveToDeclaredType(node, node.member.ref.type);
+            // member access is resolved only in the context of the operand type
+            this.linkReference(node, 'member', document, [provider], true);
+            if (node.member.ref) {
+                this.resolveToDeclaredType(node, node.member.ref.type);
+            }
         }
     }
 

packages/schema/tests/schema/validation/attribute-validation.test.ts

@@ -1017,7 +1017,7 @@ describe('Attribute tests', () => {
                 @@allow('all', auth().email != null)
             }
         `)
-        ).toContain(`Could not resolve reference to DataModelField named 'email'.`);
+        ).toContain(`expression cannot be resolved`);
     });
 
     it('collection predicate expression check', async () => {

tests/integration/tests/regression/issue-756.test.ts

@@ -0,0 +1,33 @@
+import { loadModel, loadModelWithError } from '@zenstackhq/testtools';
+
+describe('Regression: issue 756', () => {
+    it('regression', async () => {
+        expect(
+            await loadModelWithError(
+                `
+        generator client {
+            provider = "prisma-client-js"
+        }
+
+        datasource db {
+            provider = "postgresql"
+            url      = env("DATABASE_URL")
+        }
+
+        model User {
+            id Int @id @default(autoincrement())
+            email Int
+            posts Post[]
+          }
+
+          model Post {
+            id Int @id @default(autoincrement())
+            author User? @relation(fields: [authorId], references: [id])
+            authorId Int
+            @@allow('all', auth().posts.authorId == authorId)
+          }
+        `
+            )
+        ).toContain('expression cannot be resolved');
+    });
+});