Ensure queries are not pushed on connections with active cursors - fixes #411

Author: porsager

src/connection.js

@@ -166,6 +166,7 @@ function Connection(options, queues = {}, { onopen = noop, onend = noop, onclose
       build(q)
       return write(toBuffer(q))
         && !q.describeFirst
+        && !q.cursorFn
         && sent.length < max_pipeline
         && (!q.options.onexecute || q.options.onexecute(connection))
     } catch (error) {

tests/index.js

@@ -2472,3 +2472,24 @@ t('Insert array with undefined transform', async() => {
     await sql`drop table test`
   ]
 })
+
+t('concurrent cursors', async() => {
+  const xs = []
+
+  await Promise.all([...Array(7)].map((x, i) => [
+    sql`select ${ i }::int as a, generate_series(1, 2) as x`.cursor(([x]) => xs.push(x.a + x.x))
+  ]).flat())
+
+  return ['12233445566778', xs.join('')]
+})
+
+t('concurrent cursors multiple connections', async() => {
+  const sql = postgres({ ...options, max: 2 })
+  const xs = []
+
+  await Promise.all([...Array(7)].map((x, i) => [
+    sql`select ${ i }::int as a, generate_series(1, 2) as x`.cursor(([x]) => xs.push(x.a + x.x))
+  ]).flat())
+
+  return ['12233445566778', xs.sort().join('')]
+})