Linting + handlind json null values

Signed-off-by: Simon Ferquel <simon.ferquel@docker.com>

Author: simonferquel

cli/command/cli_test.go

@@ -9,7 +9,6 @@ import (
 
 	cliconfig "github.com/docker/cli/cli/config"
 	"github.com/docker/cli/cli/config/configfile"
-	"github.com/docker/cli/cli/context/store"
 	"github.com/docker/cli/cli/flags"
 	"github.com/docker/docker/api"
 	"github.com/docker/docker/api/types"
@@ -248,38 +247,3 @@ func TestGetClientWithPassword(t *testing.T) {
 		})
 	}
 }
-
-type emptyContextStore struct {
-}
-
-func (emptyContextStore) ListContexts() (map[string]store.ContextMetadata, error) {
-	return nil, nil
-}
-
-func (emptyContextStore) CreateOrUpdateContext(name string, meta store.ContextMetadata) error {
-	return nil
-}
-
-func (emptyContextStore) RemoveContext(name string) error {
-	return nil
-}
-
-func (emptyContextStore) GetContextMetadata(name string) (store.ContextMetadata, error) {
-	return store.ContextMetadata{}, nil
-}
-
-func (emptyContextStore) ResetContextTLSMaterial(name string, data *store.ContextTLSData) error {
-	return nil
-}
-
-func (emptyContextStore) ResetContextEndpointTLSMaterial(contextName string, endpointName string, data *store.EndpointTLSData) error {
-	return nil
-}
-
-func (emptyContextStore) ListContextTLSFiles(name string) (map[string]store.EndpointFiles, error) {
-	return nil, nil
-}
-
-func (emptyContextStore) GetContextTLSData(contextName, endpointName, fileName string) ([]byte, error) {
-	return nil, nil
-}

cli/context/store/metadatastore.go

@@ -36,7 +36,7 @@ func (s *metadataStore) createOrUpdate(name string, meta ContextMetadata) error
 }
 
 func parseTypedOrMap(payload []byte, getter TypeGetter) (interface{}, error) {
-	if len(payload) == 0 {
+	if len(payload) == 0 || string(payload) == "null" {
 		return nil, nil
 	}
 	if getter == nil {
@@ -63,7 +63,9 @@ func (s *metadataStore) get(name string) (ContextMetadata, error) {
 	r := ContextMetadata{
 		Endpoints: make(map[string]interface{}),
 	}
-	err = json.Unmarshal(bytes, &untyped)
+	if err := json.Unmarshal(bytes, &untyped); err != nil {
+		return ContextMetadata{}, err
+	}
 	if r.Metadata, err = parseTypedOrMap(untyped.Metadata, s.config.contextType); err != nil {
 		return ContextMetadata{}, err
 	}