diff --git a/scheduler/filter/attributes.go b/scheduler/filter/attribute.go
similarity index 100%
rename from scheduler/filter/attributes.go
rename to scheduler/filter/attribute.go
diff --git a/scheduler/filter/attribute_test.go b/scheduler/filter/attribute_test.go
new file mode 100644
index 0000000000..ce99cc958b
--- /dev/null
+++ b/scheduler/filter/attribute_test.go
@@ -0,0 +1,64 @@
+package filter
+
+import (
+	"testing"
+
+	"github.com/docker/swarm/cluster"
+	"github.com/samalba/dockerclient"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAttributeFilter(t *testing.T) {
+	var (
+		f     = AttributeFilter{}
+		nodes = []*cluster.Node{
+			cluster.NewNode("node-1", ""),
+			cluster.NewNode("node-2", ""),
+			cluster.NewNode("node-3", ""),
+		}
+		result []*cluster.Node
+		err    error
+	)
+
+	nodes[0].Labels = map[string]string{
+		"name":  "node0",
+		"group": "1",
+	}
+
+	nodes[1].Labels = map[string]string{
+		"name":  "node1",
+		"group": "1",
+	}
+
+	nodes[2].Labels = map[string]string{
+		"name":  "node2",
+		"group": "2",
+	}
+
+	// Without constraints we should get the unfiltered list of nodes back.
+	result, err = f.Filter(&dockerclient.ContainerConfig{}, nodes)
+	assert.NoError(t, err)
+	assert.Equal(t, result, nodes)
+
+	// Set a constraint that cannot be fullfilled and expect an error back.
+	result, err = f.Filter(&dockerclient.ContainerConfig{
+		Env: []string{"constraint:does_not_exist=true"},
+	}, nodes)
+	assert.Error(t, err)
+
+	// Set a contraint that can only be filled by a single node.
+	result, err = f.Filter(&dockerclient.ContainerConfig{
+		Env: []string{"constraint:name=node1"},
+	}, nodes)
+	assert.NoError(t, err)
+	assert.Len(t, result, 1)
+	assert.Equal(t, result[0], nodes[1])
+
+	// This constraint can only be fullfilled by a subset of nodes.
+	result, err = f.Filter(&dockerclient.ContainerConfig{
+		Env: []string{"constraint:group=1"},
+	}, nodes)
+	assert.NoError(t, err)
+	assert.Len(t, result, 2)
+	assert.NotContains(t, result, nodes[2])
+}