cli/command: add WithAPIClient

This allows the cli to be initialized with a (custom) API client.
Currently to be used for unit tests, but could be used for other
scenarios.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/cli_options.go

@@ -6,6 +6,7 @@ import (
 	"strconv"
 
 	"github.com/docker/cli/cli/streams"
+	"github.com/docker/docker/client"
 	"github.com/moby/term"
 )
 
@@ -86,3 +87,11 @@ func WithDefaultContextStoreConfig() DockerCliOption {
 		return nil
 	}
 }
+
+// WithAPIClient configures the cli to use the given API client.
+func WithAPIClient(c client.APIClient) DockerCliOption {
+	return func(cli *DockerCli) error {
+		cli.client = c
+		return nil
+	}
+}