Add test

Signed-off-by: Victor Vieux <vieux@docker.com>

scheduler/scheduler_test.go

@@ -0,0 +1,56 @@
+package scheduler
+
+import (
+	"testing"
+
+	"github.com/docker/swarm/cluster"
+	"github.com/docker/swarm/scheduler/filter"
+	"github.com/docker/swarm/scheduler/node"
+	"github.com/docker/swarm/scheduler/strategy"
+	"github.com/samalba/dockerclient"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSelectNodesForContainer(t *testing.T) {
+	var (
+		s = Scheduler{
+			strategy: &strategy.SpreadPlacementStrategy{},
+			filters:  []filter.Filter{&filter.ConstraintFilter{}},
+		}
+
+		nodes = []*node.Node{
+			{
+				ID:          "node-0-id",
+				Name:        "node-0-name",
+				Addr:        "node-0",
+				TotalMemory: 1 * 1024 * 1024 * 1024,
+				TotalCpus:   1,
+				Labels: map[string]string{
+					"group": "1",
+				},
+			},
+
+			{
+				ID:          "node-1-id",
+				Name:        "node-1-name",
+				Addr:        "node-1",
+				TotalMemory: 1 * 1024 * 1024 * 1024,
+				TotalCpus:   2,
+				Labels: map[string]string{
+					"group": "2",
+				},
+			},
+		}
+
+		config = cluster.BuildContainerConfig(dockerclient.ContainerConfig{
+			Memory:    1024 * 1024 * 1024,
+			CpuShares: 2,
+			Env:       []string{"constraint:group==~1"},
+		})
+	)
+	candidates, err := s.SelectNodesForContainer(nodes, config)
+	assert.NoError(t, err)
+	assert.Equal(t, 1, len(candidates))
+	assert.Equal(t, "node-1-id", candidates[0].ID)
+
+}