Test for error during delete

packages/postgraphile-core/__tests__/fixtures/mutations/mutation-delete-error.graphql

@@ -0,0 +1,13 @@
+mutation {
+  deleteTypeById(input: { id: 12 }) {
+    clientMutationId
+    deletedTypeId
+    type {
+      nodeId
+      id
+    }
+    query {
+      nodeId
+    }
+  }
+}

packages/postgraphile-core/__tests__/integration/__snapshots__/mutations.test.js.snap

@@ -505,6 +505,17 @@ Object {
 }
 `;
 
+exports[`mutation-delete-error.graphql 1`] = `
+Object {
+  "data": Object {
+    "deleteTypeById": null,
+  },
+  "errors": Array [
+    [GraphQLError: Nope.],
+  ],
+}
+`;
+
 exports[`mutation-update.graphql 1`] = `
 Object {
   "data": Object {

packages/postgraphile-core/__tests__/kitchen-sink-schema.sql

@@ -146,6 +146,15 @@ create table b.types (
   "nested_compound_type" b.nested_compound_type not null
 );
 
+create function b.throw_error() returns trigger as $$
+begin
+  raise exception 'Nope.';
+  return new;
+end;
+$$ language plpgsql;
+
+create trigger dont_delete before delete on b.types for each row execute procedure b.throw_error();
+
 create function a.add_1_mutation(int, int) returns int as $$ select $1 + $2 $$ language sql volatile strict;
 create function a.add_2_mutation(a int, b int default 2) returns int as $$ select $1 + $2 $$ language sql strict;
 create function a.add_3_mutation(a int, int) returns int as $$ select $1 + $2 $$ language sql volatile;