command: add tests for container diff and rename

This commit adds tests for the commands
docker diff and docker rename. Also,
it creates the mock methods of the
docker client ContainerDiff and
ContainerRename so they can
be used in the tests.

For docker diff, it covers the
cases that:
 - the command runs successfully
 - the client returns an error
 - the container id is empty

For docker rename, it covers
the cases that:
 - the command runs successfully
 - the container old name is empty
 - the container new name is empty
 - the client returns an error

Co-authored-by: Laura Brehm <laurabrehm@hey.com>
Signed-off-by: Stavros Panakakis <stavrospanakakis@gmail.com>

Author: Stavrospanakakis

cli/command/container/client_test.go

@@ -38,6 +38,8 @@ type fakeClient struct {
 	containerKillFunc       func(ctx context.Context, containerID, signal string) error
 	containerPruneFunc      func(ctx context.Context, pruneFilters filters.Args) (container.PruneReport, error)
 	containerAttachFunc     func(ctx context.Context, containerID string, options container.AttachOptions) (types.HijackedResponse, error)
+	containerDiffFunc       func(ctx context.Context, containerID string) ([]container.FilesystemChange, error)
+	containerRenameFunc     func(ctx context.Context, oldName, newName string) error
 	Version                 string
 }
 
@@ -181,3 +183,19 @@ func (f *fakeClient) ContainerAttach(ctx context.Context, containerID string, op
 	}
 	return types.HijackedResponse{}, nil
 }
+
+func (f *fakeClient) ContainerDiff(ctx context.Context, containerID string) ([]container.FilesystemChange, error) {
+	if f.containerDiffFunc != nil {
+		return f.containerDiffFunc(ctx, containerID)
+	}
+
+	return []container.FilesystemChange{}, nil
+}
+
+func (f *fakeClient) ContainerRename(ctx context.Context, oldName, newName string) error {
+	if f.containerRenameFunc != nil {
+		return f.containerRenameFunc(ctx, oldName, newName)
+	}
+
+	return nil
+}

cli/command/container/diff_test.go

@@ -0,0 +1,93 @@
+package container
+
+import (
+	"context"
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/docker/cli/internal/test"
+	"github.com/docker/docker/api/types/container"
+	"github.com/pkg/errors"
+	"gotest.tools/v3/assert"
+	is "gotest.tools/v3/assert/cmp"
+)
+
+func TestRunDiff(t *testing.T) {
+	cli := test.NewFakeCli(&fakeClient{
+		containerDiffFunc: func(
+			ctx context.Context,
+			containerID string,
+		) ([]container.FilesystemChange, error) {
+			return []container.FilesystemChange{
+				{
+					Kind: container.ChangeModify,
+					Path: "/path/to/file0",
+				},
+				{
+					Kind: container.ChangeAdd,
+					Path: "/path/to/file1",
+				},
+				{
+					Kind: container.ChangeDelete,
+					Path: "/path/to/file2",
+				},
+			}, nil
+		},
+	})
+
+	cmd := NewDiffCommand(cli)
+	cmd.SetOut(io.Discard)
+
+	cmd.SetArgs([]string{"container-id"})
+
+	err := cmd.Execute()
+	assert.NilError(t, err)
+
+	diff := strings.SplitN(cli.OutBuffer().String(), "\n", 3)
+	assert.Assert(t, is.Len(diff, 3))
+
+	file0 := strings.TrimSpace(diff[0])
+	file1 := strings.TrimSpace(diff[1])
+	file2 := strings.TrimSpace(diff[2])
+
+	assert.Check(t, is.Equal(file0, "C /path/to/file0"))
+	assert.Check(t, is.Equal(file1, "A /path/to/file1"))
+	assert.Check(t, is.Equal(file2, "D /path/to/file2"))
+}
+
+func TestRunDiffClientError(t *testing.T) {
+	clientError := errors.New("client error")
+
+	cli := test.NewFakeCli(&fakeClient{
+		containerDiffFunc: func(
+			ctx context.Context,
+			containerID string,
+		) ([]container.FilesystemChange, error) {
+			return nil, clientError
+		},
+	})
+
+	cmd := NewDiffCommand(cli)
+	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
+
+	cmd.SetArgs([]string{"container-id"})
+
+	err := cmd.Execute()
+	assert.ErrorIs(t, err, clientError)
+}
+
+func TestRunDiffEmptyContainerError(t *testing.T) {
+	cli := test.NewFakeCli(&fakeClient{})
+
+	cmd := NewDiffCommand(cli)
+	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
+
+	containerID := ""
+	cmd.SetArgs([]string{containerID})
+
+	err := cmd.Execute()
+	assert.Error(t, err, "Container name cannot be empty")
+}

cli/command/container/rename_test.go

@@ -0,0 +1,77 @@
+package container
+
+import (
+	"context"
+	"io"
+	"testing"
+
+	"github.com/docker/cli/internal/test"
+	"github.com/pkg/errors"
+	"gotest.tools/v3/assert"
+	is "gotest.tools/v3/assert/cmp"
+)
+
+func TestRunRename(t *testing.T) {
+	testcases := []struct {
+		doc, oldName, newName, expectedErr string
+	}{
+		{
+			doc:         "success",
+			oldName:     "oldName",
+			newName:     "newName",
+			expectedErr: "",
+		},
+		{
+			doc:         "empty old name",
+			oldName:     "",
+			newName:     "newName",
+			expectedErr: "Error: Neither old nor new names may be empty",
+		},
+		{
+			doc:         "empty new name",
+			oldName:     "oldName",
+			newName:     "",
+			expectedErr: "Error: Neither old nor new names may be empty",
+		},
+	}
+
+	for _, tc := range testcases {
+		t.Run(tc.doc, func(t *testing.T) {
+			cli := test.NewFakeCli(&fakeClient{
+				containerRenameFunc: func(ctx context.Context, oldName, newName string) error {
+					return nil
+				},
+			})
+
+			cmd := NewRenameCommand(cli)
+			cmd.SetOut(io.Discard)
+			cmd.SetErr(io.Discard)
+			cmd.SetArgs([]string{tc.oldName, tc.newName})
+
+			err := cmd.Execute()
+
+			if tc.expectedErr != "" {
+				assert.ErrorContains(t, err, tc.expectedErr)
+			} else {
+				assert.NilError(t, err)
+			}
+		})
+	}
+}
+
+func TestRunRenameClientError(t *testing.T) {
+	cli := test.NewFakeCli(&fakeClient{
+		containerRenameFunc: func(ctx context.Context, oldName, newName string) error {
+			return errors.New("client error")
+		},
+	})
+
+	cmd := NewRenameCommand(cli)
+	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
+	cmd.SetArgs([]string{"oldName", "newName"})
+
+	err := cmd.Execute()
+
+	assert.Check(t, is.Error(err, "Error: failed to rename container named oldName"))
+}