Add new alert for no heap allocations

A new alert for "No heap allocations" has been incorporated into the row/row_test.go file. This alert uses a Prometheus query and triggers if the average is below 0.01. The test assertions are updated accordingly to check for two alerts rather than one.

row/row_test.go

@@ -69,12 +69,20 @@ func TestRowsCanHaveGraphsAndAlert(t *testing.T) {
  ),
  alert.If(alert.Avg, "A", alert.IsAbove(3)),
  ),
+ graph.Alert(
+ "No heap allocations",
+ alert.WithPrometheusQuery(
+ "A",
+ "sum(go_memstats_heap_alloc_bytes{app!=\"\"}) by (app)",
+ ),
+ alert.If(alert.Avg, "A", alert.IsBelow(0.01)),
+ ),
  ),
  )
 
  req.NoError(err)
  req.Len(panel.builder.Panels, 1)
- req.Len(panel.Alerts(), 1)
+ req.Len(panel.Alerts(), 2)
 
  req.Equal("Prometheus", panel.Alerts()[0].Datasource)
 }
@@ -107,12 +115,20 @@ func TestRowsCanHaveTimeSeriesAndAlert(t *testing.T) {
  ),
  alert.If(alert.Avg, "A", alert.IsAbove(3)),
  ),
+ timeseries.Alert(
+ "No heap allocations",
+ alert.WithPrometheusQuery(
+ "A",
+ "sum(go_memstats_heap_alloc_bytes{app!=\"\"}) by (app)",
+ ),
+ alert.If(alert.Avg, "A", alert.IsBelow(0.01)),
+ ),
  ),
  )
 
  req.NoError(err)
  req.Len(panel.builder.Panels, 1)
- req.Len(panel.Alerts(), 1)
+ req.Len(panel.Alerts(), 2)
 
  req.Equal("Prometheus", panel.Alerts()[0].Datasource)
 }