sqlite: handle thrown errors in result callback

src/node_sqlite.cc

@@ -373,7 +373,10 @@ class CustomAggregate {
       result = Local<Value>::New(isolate, agg->value);
     }
 
-    JSValueToSQLiteResult(isolate, ctx, result);
+    if (!result.IsEmpty()) {
+      JSValueToSQLiteResult(isolate, ctx, result);
+    }
+
     if (is_final) {
       DestroyAggregateData(ctx);
     }

test/parallel/test-sqlite-aggregate-function.mjs

@@ -309,6 +309,27 @@ describe('step', () => {
 });
 
 describe('result', () => {
+  test('throws if result throws an error', (t) => {
+    const db = new DatabaseSync(':memory:');
+    t.after(() => db.close());
+    db.exec('CREATE TABLE data (value INTEGER)');
+    db.exec('INSERT INTO data VALUES (1), (2), (3)');
+    db.aggregate('sum_int', {
+      start: 0,
+      step: (acc, value) => {
+        return acc + value;
+      },
+      result: () => {
+        throw new Error('result error');
+      },
+    });
+    t.assert.throws(() => {
+      db.prepare('SELECT sum_int(value) as result FROM data').get();
+    }, {
+      message: 'result error'
+    });
+  });
+
   test('executes once when options.inverse is not present', (t) => {
     const db = new DatabaseSync(':memory:');
     t.after(() => db.close());