add another test

pkg/labels/labels_test.go

@@ -0,0 +1,43 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package labels
+
+import (
+	"testing"
+)
+
+func matches(t *testing.T, ls LabelSet, want string) {
+	if ls.String() != want {
+		t.Errorf("Expected '%s', but got '%s'", want, ls.String())
+	}
+}
+
+func TestLabelSetString(t *testing.T) {
+	matches(t, LabelSet{"x": "y"}, "x=y")
+	matches(t, LabelSet{"foo": "bar"}, "foo=bar")
+	matches(t, LabelSet{"foo": "bar", "baz": "qup"}, "foo=bar,baz=qup")
+
+	// TODO: Make our label representation robust enough to handel labels
+	// with ",=!" characters in their names.
+}
+
+func TestLabelGet(t *testing.T) {
+	ls := LabelSet{"x": "y"}
+	if ls.Get("x") != "y" {
+		t.Errorf("LabelSet.Get is broken")
+	}
+}

pkg/labels/query.go

@@ -30,6 +30,11 @@ type Query interface {
 	String() string
 }
 
+// Everything returns a query that matches all labels.
+func Everything() Query {
+	return &queryTerm{}
+}
+
 // A single term of a label query.
 type queryTerm struct {
 	// Not inverts the meaning of the items in this term.
@@ -84,6 +89,17 @@ func try(queryPiece, op string) (lhs, rhs string, ok bool) {
 	return "", "", false
 }
 
+// Given a LabelSet, return a Query which will match exactly that LabelSet.
+func QueryFromSet(ls LabelSet) Query {
+	var query queryTerm
+	for l, v := range ls {
+		// Make a copy, because we're taking the address below
+		label, value := l, v
+		query.and = append(query.and, queryTerm{label: &label, value: &value})
+	}
+	return &query
+}
+
 // Takes a string repsenting a label query and returns an object suitable for matching, or an error.
 func ParseQuery(query string) (Query, error) {
 	parts := strings.Split(query, ",")