feat(validation): disallow SetNull referential action on required referenced fields

introspection-engine/introspection-engine-tests/tests/re_introspection/vitess.rs

@@ -390,7 +390,7 @@ async fn referential_actions_are_kept_intact(api: &TestApi) -> TestResult {
 
         CREATE TABLE `B` (
             id  INT AUTO_INCREMENT PRIMARY KEY,
-            aId INT NOT NULL
+            aId INT NULL
         );
     "#};
 
@@ -403,9 +403,9 @@ async fn referential_actions_are_kept_intact(api: &TestApi) -> TestResult {
         }
 
         model B {
-          id  Int @id @default(autoincrement())
-          aId Int
-          a   A   @relation(fields: [aId], references: [id], onDelete: SetNull)
+          id  Int  @id @default(autoincrement())
+          aId Int?
+          a   A?   @relation(fields: [aId], references: [id], onDelete: Restrict)
         }
     "#};
 
@@ -416,9 +416,9 @@ async fn referential_actions_are_kept_intact(api: &TestApi) -> TestResult {
         }
 
         model B {
-          id  Int @id @default(autoincrement())
-          aId Int
-          a   A   @relation(fields: [aId], references: [id], onDelete: SetNull)
+          id  Int  @id @default(autoincrement())
+          aId Int?
+          a   A?   @relation(fields: [aId], references: [id], onDelete: Restrict)
         }
     "#]];
 

psl/psl-core/src/validate/validation_pipeline/validations.rs

@@ -154,6 +154,7 @@ pub(super) fn validate(ctx: &mut Context<'_>) {
                 relations::field_arity(relation, ctx);
                 relations::referencing_scalar_field_types(relation, ctx);
                 relations::has_a_unique_constraint_name(&names, relation, ctx);
+                relations::required_relation_cannot_use_set_null(relation, ctx);
 
                 if relation.is_one_to_one() {
                     relations::one_to_one::both_sides_are_defined(relation, ctx);
@@ -170,6 +171,7 @@ pub(super) fn validate(ctx: &mut Context<'_>) {
                     relations::one_to_many::referential_actions(relation, ctx);
                 }
             }
+
             RefinedRelationWalker::ImplicitManyToMany(relation) => {
                 use relations::many_to_many::implicit;
 
@@ -178,6 +180,7 @@ pub(super) fn validate(ctx: &mut Context<'_>) {
                 implicit::validate_no_referential_actions(relation, ctx);
                 implicit::cannot_define_references_argument(relation, ctx);
             }
+
             RefinedRelationWalker::TwoWayEmbeddedManyToMany(relation) => {
                 use relations::many_to_many::embedded;
 

psl/psl-core/src/validate/validation_pipeline/validations/relations.rs

@@ -8,6 +8,7 @@ use super::constraint_namespace::ConstraintName;
 use crate::datamodel_connector::{walker_ext_traits::*, Connector, ConnectorCapability, RelationMode};
 use crate::{diagnostics::DatamodelError, validate::validation_pipeline::context::Context};
 use itertools::Itertools;
+use parser_database::ReferentialAction;
 use parser_database::{
     ast::WithSpan,
     walkers::{CompleteInlineRelationWalker, InlineRelationWalker, RelationFieldWalker},
@@ -525,3 +526,39 @@ fn is_empty_fields<T>(fields: Option<impl ExactSizeIterator<Item = T>>) -> bool
         Some(fields) => fields.len() == 0,
     }
 }
+
+/// There cannot be any required field in a relation where one of the referential actions is SetNull.
+pub(crate) fn required_relation_cannot_use_set_null(relation: InlineRelationWalker<'_>, ctx: &mut Context<'_>) {
+    // return early if there's no relation field on the referencing model
+    let forward = match relation.forward_relation_field() {
+        Some(forward) => forward,
+        None => return,
+    };
+
+    // return early if no referencing field is required
+    if forward
+        .referencing_fields()
+        .map(|mut fields| fields.all(|f| !f.ast_field().arity.is_required()))
+        .unwrap_or_default()
+    {
+        return;
+    }
+
+    if let Some(ReferentialAction::SetNull) = forward.explicit_on_delete() {
+        ctx.push_error(DatamodelError::new_attribute_validation_error(
+            r#"The `onDelete` referential action of a relation must not be set to `SetNull` when a referenced field is required.
+Either choose another referential action, or make the referenced fields optional."#,
+            RELATION_ATTRIBUTE_NAME,
+            forward.ast_field().span(),
+        ))
+    }
+
+    if let Some(ReferentialAction::SetNull) = forward.explicit_on_update() {
+        ctx.push_error(DatamodelError::new_attribute_validation_error(
+            r#"The `onUpdate` referential action of a relation must not be set to `SetNull` when a referenced field is required.
+Either choose another referential action, or make the referenced fields optional."#,
+            RELATION_ATTRIBUTE_NAME,
+            forward.ast_field().span(),
+        ))
+    }
+}

psl/psl/tests/attributes/relations/referential_actions.rs

@@ -19,9 +19,9 @@ fn on_delete_actions() {
             }}
 
             model B {{
-                id Int @id
-                aId Int
-                a A @relation(fields: [aId], references: [id], onDelete: {})
+                id  Int  @id
+                aId Int?
+                a   A?   @relation(fields: [aId], references: [id], onDelete: {})
             }}
         "#,
             action
@@ -47,9 +47,9 @@ fn on_update_actions() {
             }}
 
             model B {{
-                id Int @id
-                aId Int
-                a A @relation(fields: [aId], references: [id], onUpdate: {})
+                id  Int  @id
+                aId Int?
+                a   A?   @relation(fields: [aId], references: [id], onUpdate: {})
             }}
         "#,
             action
@@ -80,9 +80,9 @@ fn actions_on_mongo() {
             }}
 
             model B {{
-                id Int @id @map("_id")
-                aId Int
-                a A @relation(fields: [aId], references: [id], onDelete: {action})
+                id   Int @id @map("_id")
+                aId  Int?
+                a A? @relation(fields: [aId], references: [id], onDelete: {action})
             }}
         "#,
             action = action
@@ -119,9 +119,9 @@ fn actions_on_mysql_with_prisma_relation_mode() {
             }}
 
             model B {{
-                id Int @id
-                aId Int
-                a A @relation(fields: [aId], references: [id], onDelete: {action})
+                id  Int  @id
+                aId Int?
+                a   A?   @relation(fields: [aId], references: [id], onDelete: {action})
             }}
         "#,
             action = action
@@ -158,9 +158,9 @@ fn actions_on_sqlserver_with_prisma_relation_mode() {
             }}
 
             model B {{
-                id Int @id
-                aId Int
-                a A @relation(fields: [aId], references: [id], onDelete: {action})
+                id  Int  @id
+                aId Int?
+                a   A?   @relation(fields: [aId], references: [id], onDelete: {action})
             }}
         "#,
             action = action
@@ -197,9 +197,9 @@ fn actions_on_cockroachdb_with_prisma_relation_mode() {
             }}
 
             model B {{
-                id Int @id
-                aId Int
-                a A @relation(fields: [aId], references: [id], onDelete: {action})
+                id  Int  @id
+                aId Int?
+                a   A?   @relation(fields: [aId], references: [id], onDelete: {action})
             }}
         "#,
             action = action
@@ -236,9 +236,9 @@ fn actions_on_postgres_with_prisma_relation_mode() {
             }}
 
             model B {{
-                id Int @id
-                aId Int
-                a A @relation(fields: [aId], references: [id], onDelete: {action})
+                id  Int  @id
+                aId Int?
+                a   A?   @relation(fields: [aId], references: [id], onDelete: {action})
             }}
         "#,
             action = action
@@ -275,9 +275,9 @@ fn actions_on_sqlite_with_prisma_relation_mode() {
             }}
 
             model B {{
-                id Int @id
-                aId Int
-                a A @relation(fields: [aId], references: [id], onDelete: {action})
+                id  Int  @id
+                aId Int?
+                a   A?   @relation(fields: [aId], references: [id], onDelete: {action})
             }}
         "#,
             action = action
@@ -314,9 +314,9 @@ fn on_delete_actions_should_work_on_prisma_relation_mode() {
             }}
 
             model B {{
-                id Int @id
-                aId Int
-                a A @relation(fields: [aId], references: [id], onDelete: {action})
+                id  Int  @id
+                aId Int?
+                a   A?   @relation(fields: [aId], references: [id], onDelete: {action})
             }}
         "#,
             action = action

psl/psl/tests/validation/relations/set_null_is_not_valid_on_mixed_fields.prisma

@@ -0,0 +1,32 @@
+model SomeUser {
+  id      Int      @id
+  ref     Int
+  profile Profile?
+
+  @@unique([id, ref])
+}
+
+model Profile {
+  id       Int       @id
+  user     SomeUser? @relation(fields: [user_id, user_ref], references: [id, ref], onUpdate: SetNull, onDelete: SetNull)
+  user_id  Int?
+  user_ref Int
+
+  @@unique([user_id, user_ref])
+}
+// error: Error parsing attribute "@relation": The `onDelete` referential action of a relation must not be set to `SetNull` when a referenced field is required.
+// Either choose another referential action, or make the referenced fields optional.
+//   -->  schema.prisma:11
+//    | 
+// 10 |   id       Int       @id
+// 11 |   user     SomeUser? @relation(fields: [user_id, user_ref], references: [id, ref], onUpdate: SetNull, onDelete: SetNull)
+// 12 |   user_id  Int?
+//    | 
+// error: Error parsing attribute "@relation": The `onUpdate` referential action of a relation must not be set to `SetNull` when a referenced field is required.
+// Either choose another referential action, or make the referenced fields optional.
+//   -->  schema.prisma:11
+//    | 
+// 10 |   id       Int       @id
+// 11 |   user     SomeUser? @relation(fields: [user_id, user_ref], references: [id, ref], onUpdate: SetNull, onDelete: SetNull)
+// 12 |   user_id  Int?
+//    | 

psl/psl/tests/validation/relations/set_null_is_not_valid_on_required_fields.prisma

@@ -0,0 +1,26 @@
+model SomeUser {
+  id      Int      @id
+  profile Profile?
+}
+
+model Profile {
+  id      Int       @id
+  user    SomeUser? @relation(fields: [user_id], references: [id], onUpdate: SetNull, onDelete: SetNull)
+  user_id Int       @unique
+}
+// error: Error parsing attribute "@relation": The `onDelete` referential action of a relation must not be set to `SetNull` when a referenced field is required.
+// Either choose another referential action, or make the referenced fields optional.
+//   -->  schema.prisma:8
+//    | 
+//  7 |   id      Int       @id
+//  8 |   user    SomeUser? @relation(fields: [user_id], references: [id], onUpdate: SetNull, onDelete: SetNull)
+//  9 |   user_id Int       @unique
+//    | 
+// error: Error parsing attribute "@relation": The `onUpdate` referential action of a relation must not be set to `SetNull` when a referenced field is required.
+// Either choose another referential action, or make the referenced fields optional.
+//   -->  schema.prisma:8
+//    | 
+//  7 |   id      Int       @id
+//  8 |   user    SomeUser? @relation(fields: [user_id], references: [id], onUpdate: SetNull, onDelete: SetNull)
+//  9 |   user_id Int       @unique
+//    | 

psl/psl/tests/validation/relations/set_null_still_valid_on_optional_fields.prisma

@@ -0,0 +1,10 @@
+model SomeUser {
+  id      Int      @id
+  profile Profile?
+}
+
+model Profile {
+  id      Int       @id
+  user    SomeUser? @relation(fields: [user_id], references: [id], onUpdate: SetNull, onDelete: SetNull)
+  user_id Int?      @unique
+}