Full implementation for OSX ready

Signed-off-by: avaid96 <avaid1996@gmail.com>

credentials/credentials.go

@@ -17,6 +17,11 @@ type Credentials struct {
 	Secret    string
 }
 
+type KeyData struct{
+	Path	  string
+	Username  string
+}
+
 // Serve initializes the credentials helper and parses the action argument.
 // This function is designed to be called from a command line interface.
 // It uses os.Args[1] as the key for the action.
@@ -127,3 +132,26 @@ func Erase(helper Helper, reader io.Reader) error {
 
 	return helper.Delete(serverURL)
 }
+
+ //List returns all the serverURLs of keys in
+ //the OS store as a list of strings
+func List(helper Helper, writer io.Writer) error {
+	x, y, err := helper.List()
+	if err != nil {
+		return err
+	}
+	keyDataList := []KeyData{}
+	for index, _ := range(x) {
+		keyDataObj := KeyData{
+			Path:x[index],
+			Username:y[index],
+		}
+		keyDataList = append([]KeyData{keyDataObj}, keyDataList...)
+	}
+	buffer := new(bytes.Buffer)
+	if err := json.NewEncoder(buffer).Encode(keyDataList); err != nil {
+		return err
+	}
+	fmt.Fprint(writer, buffer.String())
+	return nil
+}

credentials/credentials_test.go

@@ -36,6 +36,11 @@ func (m *memoryStore) Get(serverURL string) (string, string, error) {
 	return c.Username, c.Secret, nil
 }
 
+func (m *memoryStore) List() ([]string, []string, error) {
+	//Simply a placeholder to let memoryStore be a valid implementation of Helper interface
+	return nil, nil, nil
+}
+
 func TestStore(t *testing.T) {
 	serverURL := "https://index.docker.io/v1/"
 	creds := &Credentials{
@@ -138,3 +143,16 @@ func TestErase(t *testing.T) {
 		t.Fatal("expected error getting missing creds, got empty")
 	}
 }
+
+func TestList(t *testing.T) {
+	//This tests that there is proper input an output into the byte stream
+	//Individual stores are very OS specific and have been tested in osxkeychain and secretservice respectively
+	out := new(bytes.Buffer)
+	h := newMemoryStore()
+	if err := List(h, out); err != nil {
+		t.Fatal(err)
+	}
+	if out.Len() == 0 {
+		t.Fatalf("expected output in the writer, got %d", 0)
+	}
+}

credentials/helper.go

@@ -9,4 +9,7 @@ type Helper interface {
 	// Get retrieves credentials from the store.
 	// It returns username and secret as strings.
 	Get(serverURL string) (string, string, error)
+	// List returns all the serverURLs of keys in
+	// the OS store as a list of strings
+	List() ([]string, []string, error)
 }