Uniform volume prune output msg with other prune commands

- Return error when user refuses at confirmation prompt
- Avoid sending space freed msg if user cancelled
- Fixed unit tests

Signed-off-by: Christopher Petito <chrisjpetito@gmail.com>

cli/command/volume/prune.go

@@ -32,6 +32,10 @@ func NewPruneCommand(dockerCli command.Cli) *cobra.Command {
 		RunE: func(cmd *cobra.Command, args []string) error {
 			spaceReclaimed, output, err := runPrune(cmd.Context(), dockerCli, options)
 			if err != nil {
+				if errdefs.IsCancelled(err) {
+					fmt.Fprintln(dockerCli.Out(), output)
+					return nil
+				}
 				return err
 			}
 			if output != "" {
@@ -77,7 +81,7 @@ func runPrune(ctx context.Context, dockerCli command.Cli, options pruneOptions)
 		warning = allVolumesWarning
 	}
 	if !options.force && !command.PromptForConfirmation(dockerCli.In(), dockerCli.Out(), warning) {
-		return 0, "", nil
+		return 0, "", errdefs.Cancelled(errors.New("user cancelled operation"))
 	}
 
 	report, err := dockerCli.Client().VolumesPrune(ctx, pruneFilters)

cli/command/volume/prune_test.go

@@ -73,13 +73,15 @@ func TestVolumePruneSuccess(t *testing.T) {
 	testCases := []struct {
 		name            string
 		args            []string
+		input           string
 		volumePruneFunc func(args filters.Args) (types.VolumesPruneReport, error)
 	}{
 		{
-			name: "all",
-			args: []string{"--all"},
+			name:  "all",
+			args:  []string{"--all"},
+			input: "y",
 			volumePruneFunc: func(pruneFilter filters.Args) (types.VolumesPruneReport, error) {
-				assert.Check(t, is.Equal([]string{"true"}, pruneFilter.Get("all")))
+				assert.Check(t, is.DeepEqual([]string{"true"}, pruneFilter.Get("all")))
 				return types.VolumesPruneReport{}, nil
 			},
 		},
@@ -91,10 +93,11 @@ func TestVolumePruneSuccess(t *testing.T) {
 			},
 		},
 		{
-			name: "label-filter",
-			args: []string{"--filter", "label=foobar"},
+			name:  "label-filter",
+			args:  []string{"--filter", "label=foobar"},
+			input: "y",
 			volumePruneFunc: func(pruneFilter filters.Args) (types.VolumesPruneReport, error) {
-				assert.Check(t, is.Equal([]string{"foobar"}, pruneFilter.Get("label")))
+				assert.Check(t, is.DeepEqual([]string{"foobar"}, pruneFilter.Get("label")))
 				return types.VolumesPruneReport{}, nil
 			},
 		},
@@ -104,6 +107,9 @@ func TestVolumePruneSuccess(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			cli := test.NewFakeCli(&fakeClient{volumePruneFunc: tc.volumePruneFunc})
 			cmd := NewPruneCommand(cli)
+			if tc.input != "" {
+				cli.SetIn(streams.NewIn(io.NopCloser(strings.NewReader(tc.input))))
+			}
 			cmd.SetOut(io.Discard)
 			cmd.SetArgs(tc.args)
 			err := cmd.Execute()

cli/command/volume/testdata/volume-prune-no.golden

@@ -1,2 +1,2 @@
 WARNING! This will remove anonymous local volumes not used by at least one container.
-Are you sure you want to continue? [y/N] Total reclaimed space: 0B
+Are you sure you want to continue? [y/N]