add barrier ast

pipeline/tick/ast.go

@@ -88,6 +88,8 @@ func (a *AST) Create(n pipeline.Node, parents []ast.Node) (ast.Node, error) {
 		return NewJoin(parents).Build(node)
 	case *pipeline.AlertNode:
 		return NewAlert(parents).Build(node)
+	case *pipeline.BarrierNode:
+		return NewBarrierNode(parents).Build(node)
 	case *pipeline.CombineNode:
 		return NewCombine(parents).Build(node)
 	case *pipeline.DefaultNode:

pipeline/tick/barrier.go

@@ -0,0 +1,28 @@
+package tick
+
+import (
+	"github.com/influxdata/kapacitor/pipeline"
+	"github.com/influxdata/kapacitor/tick/ast"
+)
+
+// BarrierNode converts the window pipeline node into the TICKScript AST
+type BarrierNode struct {
+	Function
+}
+
+// NewBarrierNode creates a Barrier function builder
+func NewBarrierNode(parents []ast.Node) *BarrierNode {
+	return &BarrierNode{
+		Function{
+			Parents: parents,
+		},
+	}
+}
+
+// Build creates a window ast.Node
+func (n *BarrierNode) Build(b *pipeline.BarrierNode) (ast.Node, error) {
+	n.Pipe("barrier").
+		Dot("idle", b.Idle).
+		Dot("period", b.Period)
+	return n.prev, n.err
+}

pipeline/tick/barrier_test.go

@@ -0,0 +1,61 @@
+package tick_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/influxdata/kapacitor/pipeline"
+)
+
+func TestBarrierNode(t *testing.T) {
+	type args struct {
+		idle   time.Duration
+		period time.Duration
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "barrier with idle",
+			args: args{
+				idle: time.Second,
+			},
+			want: `stream
+    |from()
+    |barrier()
+        .idle(1s)
+`,
+		},
+		{
+			name: "barrier with period",
+			args: args{
+				period: time.Second,
+			},
+			want: `stream
+    |from()
+    |barrier()
+        .period(1s)
+`,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			stream := &pipeline.StreamNode{}
+			pipe := pipeline.CreatePipelineSources(stream)
+
+			b := stream.From().Barrier()
+			b.Idle = tt.args.idle
+			b.Period = tt.args.period
+
+			got, err := PipelineTick(pipe)
+			if err != nil {
+				t.Fatalf("Unexpected error building pipeline %v", err)
+			}
+			if got != tt.want {
+				t.Errorf("%q. TestBarrier() =\n%v\n want\n%v\n", tt.name, got, tt.want)
+			}
+		})
+	}
+}