[Delegations prereq] Move set utils to an internal helper package (#191)

Splitting up https://github.com/theupdateframework/go-tuf/pull/175/files

Author: ethan-lowman-dd

client/client_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	tuf "github.com/theupdateframework/go-tuf"
 	"github.com/theupdateframework/go-tuf/data"
+	"github.com/theupdateframework/go-tuf/internal/sets"
 	"github.com/theupdateframework/go-tuf/pkg/keys"
 	"github.com/theupdateframework/go-tuf/sign"
 	"github.com/theupdateframework/go-tuf/util"
@@ -362,7 +363,7 @@ func (s *ClientSuite) TestNewRoot(c *C) {
 		}
 		role := client.db.GetRole(name)
 		c.Assert(role, NotNil)
-		c.Assert(role.KeyIDs, DeepEquals, util.StringSliceToSet(ids))
+		c.Assert(role.KeyIDs, DeepEquals, sets.StringSliceToSet(ids))
 	}
 }
 
@@ -602,7 +603,7 @@ func (s *ClientSuite) TestNewTimestampKey(c *C) {
 	}
 	role := client.db.GetRole("timestamp")
 	c.Assert(role, NotNil)
-	c.Assert(role.KeyIDs, DeepEquals, util.StringSliceToSet(newIDs))
+	c.Assert(role.KeyIDs, DeepEquals, sets.StringSliceToSet(newIDs))
 }
 
 func (s *ClientSuite) TestNewSnapshotKey(c *C) {
@@ -642,7 +643,7 @@ func (s *ClientSuite) TestNewSnapshotKey(c *C) {
 	}
 	role := client.db.GetRole("snapshot")
 	c.Assert(role, NotNil)
-	c.Assert(role.KeyIDs, DeepEquals, util.StringSliceToSet(newIDs))
+	c.Assert(role.KeyIDs, DeepEquals, sets.StringSliceToSet(newIDs))
 }
 
 func (s *ClientSuite) TestNewTargetsKey(c *C) {
@@ -685,7 +686,7 @@ func (s *ClientSuite) TestNewTargetsKey(c *C) {
 	}
 	role := client.db.GetRole("targets")
 	c.Assert(role, NotNil)
-	c.Assert(role.KeyIDs, DeepEquals, util.StringSliceToSet(newIDs))
+	c.Assert(role.KeyIDs, DeepEquals, sets.StringSliceToSet(newIDs))
 }
 
 func (s *ClientSuite) TestLocalExpired(c *C) {

internal/sets/strings.go

@@ -0,0 +1,24 @@
+package sets
+
+func StringSliceToSet(items []string) map[string]struct{} {
+	s := map[string]struct{}{}
+	for _, item := range items {
+		s[item] = struct{}{}
+	}
+	return s
+}
+
+func StringSetToSlice(items map[string]struct{}) []string {
+	ret := []string{}
+
+	for k := range items {
+		ret = append(ret, k)
+	}
+
+	return ret
+}
+
+func DeduplicateStrings(items []string) []string {
+	s := StringSliceToSet(items)
+	return StringSetToSlice(s)
+}

internal/sets/strings_test.go

@@ -0,0 +1,35 @@
+package sets
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStringSliceToSet(t *testing.T) {
+	assert.Equal(t,
+		map[string]struct{}{
+			"a": {},
+			"b": {},
+			"c": {},
+		},
+		StringSliceToSet([]string{"a", "c", "b", "c", "b"}))
+}
+
+func TestStringSetToSlice(t *testing.T) {
+	assert.ElementsMatch(t,
+		[]string{"a", "b", "c"},
+		StringSetToSlice(map[string]struct{}{
+			"a": {},
+			"b": {},
+			"c": {},
+		}),
+	)
+}
+
+func TestDeduplicateStrings(t *testing.T) {
+	assert.ElementsMatch(t,
+		[]string{"a", "b", "c"},
+		DeduplicateStrings([]string{"a", "c", "b", "c", "b"}),
+	)
+}

repo_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/secure-systems-lab/go-securesystemslib/cjson"
 	"github.com/theupdateframework/go-tuf/data"
 	"github.com/theupdateframework/go-tuf/encrypted"
+	"github.com/theupdateframework/go-tuf/internal/sets"
 	"github.com/theupdateframework/go-tuf/pkg/keys"
 	"github.com/theupdateframework/go-tuf/util"
 	"github.com/theupdateframework/go-tuf/verify"
@@ -218,7 +219,7 @@ func (rs *RepoSuite) TestGenKey(c *C) {
 		c.Assert(err, IsNil)
 		c.Assert(rootKey.MarshalPublicKey().IDs(), DeepEquals, ids)
 		role := db.GetRole("root")
-		c.Assert(role.KeyIDs, DeepEquals, util.StringSliceToSet(ids))
+		c.Assert(role.KeyIDs, DeepEquals, sets.StringSliceToSet(ids))
 
 		// check the key was saved correctly
 		localKeys, err := local.GetSigners("root")
@@ -381,7 +382,7 @@ func (rs *RepoSuite) TestAddPrivateKey(c *C) {
 		c.Assert(err, IsNil)
 		c.Assert(rootKey.MarshalPublicKey().IDs(), DeepEquals, ids)
 		role := db.GetRole("root")
-		c.Assert(role.KeyIDs, DeepEquals, util.StringSliceToSet(ids))
+		c.Assert(role.KeyIDs, DeepEquals, sets.StringSliceToSet(ids))
 
 		// check the key was saved correctly
 		localKeys, err := local.GetSigners("root")

util/util.go

@@ -266,14 +266,6 @@ func HashedPaths(p string, hashes data.Hashes) []string {
 	return paths
 }
 
-func StringSliceToSet(items []string) map[string]struct{} {
-	s := make(map[string]struct{})
-	for _, item := range items {
-		s[item] = struct{}{}
-	}
-	return s
-}
-
 func AtomicallyWriteFile(filename string, data []byte, perm os.FileMode) error {
 	dir, name := filepath.Split(filename)
 	f, err := ioutil.TempFile(dir, name)