node-postgres/test/integration/client/cancel-query-tests.js

var helper = require(__dirname+"/test-helper");

//before running this test make sure you run the script create-test-tables
test("cancellation of a query", function() {

  var client = helper.client();

  var qry = "select name from person order by name";

  client.on('drain', client.end.bind(client));

  var rows1 = 0, rows2 = 0, rows3 = 0, rows4 = 0;

  var query1 = client.query(qry);
  query1.on('row', function(row) {
    rows1++;
  });
  var query2 = client.query(qry);
  query2.on('row', function(row) {
    rows2++;
  });
  var query3 = client.query(qry);
  query3.on('row', function(row) {
    rows3++;
  });
  var query4 = client.query(qry);
  query4.on('row', function(row) {
    rows4++;
  });

  helper.pg.cancel(helper.config, client, query1);
  helper.pg.cancel(helper.config, client, query2);
  helper.pg.cancel(helper.config, client, query4);

  setTimeout(function() {
    assert.equal(rows1, 0);
    assert.equal(rows2, 0);
    assert.equal(rows4, 0);
  }, 2000);

  assert.emits(query3, 'end', function() {
    test("returned right number of rows", function() {
      assert.equal(rows3, 26);
    });
  });
});