feat: add TransactionStatus to Connection (#123)

Co-authored-by: Leonardo Zanivan <leo.zanivan@okta.com>

Author: panga

index.js

@@ -62,6 +62,12 @@ PQ.prototype.serverVersion = function () {
   return this.$serverVersion();
 };
 
+// returns the current in-transaction status of the server
+// 0=IDLE, 1=ACTIVE, 2=INTRANS, 3=INERROR, 4=UNKNOWN
+PQ.prototype.transactionStatus = function () {
+  return this.$transactionStatus();
+};
+
 //finishes the connection & closes it
 PQ.prototype.finish = function () {
   this.connected = false;

src/addon.cc

@@ -15,6 +15,7 @@ NAN_MODULE_INIT(InitAddon) {
   Nan::SetPrototypeMethod(tpl, "$resultErrorFields", Connection::ResultErrorFields);
   Nan::SetPrototypeMethod(tpl, "$socket", Connection::Socket);
   Nan::SetPrototypeMethod(tpl, "$serverVersion", Connection::ServerVersion);
+  Nan::SetPrototypeMethod(tpl, "$transactionStatus", Connection::TransactionStatus);
 
   //sync query functions
   Nan::SetPrototypeMethod(tpl, "$exec", Connection::Exec);

src/connection.cc

@@ -91,6 +91,13 @@ NAN_METHOD(Connection::ServerVersion) {
   info.GetReturnValue().Set(PQserverVersion(self->pq));
 }
 
+NAN_METHOD(Connection::TransactionStatus) {
+  TRACE("Connection::TransactionStatus");
+  Connection* self = NODE_THIS();
+  int status = PQtransactionStatus(self->pq);
+  info.GetReturnValue().Set(status);
+}
+
 
 NAN_METHOD(Connection::Exec) {
   Connection *self = NODE_THIS();

src/connection.h

@@ -56,6 +56,7 @@ class Connection : public Nan::ObjectWrap {
     static NAN_METHOD(PutCopyEnd);
     static NAN_METHOD(GetCopyData);
     static NAN_METHOD(Cancel);
+    static NAN_METHOD(TransactionStatus);
 #ifdef PIPELINE_MODE_SUPPORTED
     static NAN_METHOD(EnterPipelineMode);
     static NAN_METHOD(ExitPipelineMode);

test/transaction-status.js

@@ -0,0 +1,66 @@
+var Libpq = require('../');
+var assert = require('assert');
+
+describe('transactionStatus', function() {
+
+  it('returns PQTRANS_UNKNOWN when not connected', function() {
+    var pq = new Libpq();
+    assert.strictEqual(pq.transactionStatus(), 4);
+  });
+
+  it('returns PQTRANS_IDLE after connecting', function() {
+    var pq = new Libpq();
+    pq.connectSync();
+    assert.strictEqual(pq.transactionStatus(), 0);
+    pq.finish();
+  });
+
+  it('returns PQTRANS_IDLE after a simple query', function() {
+    var pq = new Libpq();
+    pq.connectSync();
+    pq.exec('SELECT 1');
+    assert.strictEqual(pq.transactionStatus(), 0);
+    pq.finish();
+  });
+
+  it('returns PQTRANS_INTRANS inside a transaction', function() {
+    var pq = new Libpq();
+    pq.connectSync();
+    pq.exec('BEGIN');
+    assert.strictEqual(pq.transactionStatus(), 2);
+    pq.exec('ROLLBACK');
+    pq.finish();
+  });
+
+  it('returns PQTRANS_IDLE after COMMIT', function() {
+    var pq = new Libpq();
+    pq.connectSync();
+    pq.exec('BEGIN');
+    assert.strictEqual(pq.transactionStatus(), 2);
+    pq.exec('COMMIT');
+    assert.strictEqual(pq.transactionStatus(), 0);
+    pq.finish();
+  });
+
+  it('returns PQTRANS_INERROR after a failed query in a transaction', function() {
+    var pq = new Libpq();
+    pq.connectSync();
+    pq.exec('BEGIN');
+    pq.exec('SELECT FROM nonexistent_table_xyz');
+    assert.strictEqual(pq.transactionStatus(), 3);
+    pq.exec('ROLLBACK');
+    pq.finish();
+  });
+
+  it('returns PQTRANS_IDLE after ROLLBACK from error state', function() {
+    var pq = new Libpq();
+    pq.connectSync();
+    pq.exec('BEGIN');
+    pq.exec('SELECT FROM nonexistent_table_xyz');
+    assert.strictEqual(pq.transactionStatus(), 3);
+    pq.exec('ROLLBACK');
+    assert.strictEqual(pq.transactionStatus(), 0);
+    pq.finish();
+  });
+
+});