Reused existing relation name to produce opposite relation while expanding polymorphic relations (#1572)

Co-authored-by: Yiming <[email protected]>
Co-authored-by: ymc9 <[email protected]>

Author: irvinzz

packages/schema/src/plugins/prisma/schema-generator.ts

@@ -412,6 +412,7 @@ export class PrismaSchemaGenerator {
                 const relAttr = getAttribute(field, '@relation');
                 if (relAttr) {
                     const fieldsArg = getAttributeArg(relAttr, 'fields');
+                    const nameArg = getAttributeArg(relAttr, 'name') as LiteralExpr;
                     if (fieldsArg) {
                         // for reach foreign key field pointing to the delegate model, we need to create an aux foreign key
                         // to point to the concrete model
@@ -441,7 +442,7 @@ export class PrismaSchemaGenerator {
 
                         const addedRel = new PrismaFieldAttribute('@relation', [
                             // use field name as relation name for disambiguation
-                            new PrismaAttributeArg(undefined, new AttributeArgValue('String', auxRelationField.name)),
+                            new PrismaAttributeArg(undefined, new AttributeArgValue('String', nameArg?.value || auxRelationField.name)),
                             new PrismaAttributeArg('fields', fieldsArg),
                             new PrismaAttributeArg('references', referencesArg),
                         ]);

tests/regression/tests/issue-1575.test.ts

@@ -0,0 +1,29 @@
+import { loadSchema } from '@zenstackhq/testtools';
+describe('issue 1575', () => {
+    it('regression', async () => {
+        await loadSchema(
+            `
+            model UserAssets {
+                id       String @id @default(cuid())
+                videoId         String
+                videoStream     Asset @relation("userVideo", fields: [videoId], references: [id])
+                subtitleId      String
+                subtitlesAsset  Asset @relation("userSubtitles", fields: [subtitleId], references: [id])
+            }
+
+            model Asset {
+                id              String @id @default(cuid())
+                type            String
+                userVideo       UserAssets[] @relation("userVideo")
+                userSubtitles   UserAssets[] @relation("userSubtitles")
+
+                @@delegate(type)
+            }
+
+            model Movie extends Asset {
+                duration    Int
+            }
+            `
+        );
+    });
+});