cli: improve argument validation output

Improve the output for these validation errors:

- Removes the short command description from the output. This information
  does not provide much useful help, and distracts from the error message.
- Reduces punctuation, and
- Prefixes the error message with the binary / root-command name
  (usually `docker:`) to be consistent with other similar errors.
- Adds an empty line between the error-message and the "call to action"
  (`Run 'docker volume --help'...` in the example below). This helps
  separating the error message and "usage" from the call-to-action.

Before this patch:

    $ docker volume ls one two three
    "docker volume ls" accepts no arguments.
    See 'docker volume ls --help'.

    Usage:  docker volume ls [OPTIONS]

    List volumes

    $ docker volume create one two three
    "docker volume create" requires at most 1 argument.
    See 'docker volume create --help'.

    Usage:  docker volume create [OPTIONS] [VOLUME]

    Create a volume

With this patch:

    $ docker volume ls one two three
    docker: 'docker volume ls' accepts no arguments

    Usage:  docker volume ls [OPTIONS]

    Run 'docker volume ls --help' for more information

    $ docker voludocker volume create one two three
    docker: 'docker volume create' requires at most 1 argument

    Usage:  docker volume create [OPTIONS] [VOLUME]

    SRun 'docker volume create --help' for more information

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

cli/command/checkpoint/create_test.go

@@ -20,11 +20,11 @@ func TestCheckpointCreateErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{"too-few-arguments"},
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args:          []string{"too", "many", "arguments"},
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args: []string{"foo", "bar"},

cli/command/checkpoint/list_test.go

@@ -20,11 +20,11 @@ func TestCheckpointListErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args:          []string{"too", "many", "arguments"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args: []string{"foo"},

cli/command/checkpoint/remove_test.go

@@ -19,11 +19,11 @@ func TestCheckpointRemoveErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{"too-few-arguments"},
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args:          []string{"too", "many", "arguments"},
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args: []string{"foo", "bar"},

cli/command/config/create_test.go

@@ -28,11 +28,11 @@ func TestConfigCreateErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{"too_few"},
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args:          []string{"too", "many", "arguments"},
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args: []string{"name", filepath.Join("testdata", configDataFile)},

cli/command/config/remove_test.go

@@ -19,7 +19,7 @@ func TestConfigRemoveErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{},
-			expectedError: "requires at least 1 argument.",
+			expectedError: "requires at least 1 argument",
 		},
 		{
 			args: []string{"foo"},

cli/command/image/history_test.go

@@ -23,7 +23,7 @@ func TestNewHistoryCommandErrors(t *testing.T) {
 		{
 			name:          "wrong-args",
 			args:          []string{},
-			expectedError: "requires exactly 1 argument.",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "client-error",

cli/command/image/import_test.go

@@ -22,7 +22,7 @@ func TestNewImportCommandErrors(t *testing.T) {
 		{
 			name:          "wrong-args",
 			args:          []string{},
-			expectedError: "requires at least 1 argument.",
+			expectedError: "requires at least 1 argument",
 		},
 		{
 			name:          "import-failed",

cli/command/image/inspect_test.go

@@ -21,7 +21,7 @@ func TestNewInspectCommandErrors(t *testing.T) {
 		{
 			name:          "wrong-args",
 			args:          []string{},
-			expectedError: "requires at least 1 argument.",
+			expectedError: "requires at least 1 argument",
 		},
 	}
 	for _, tc := range testCases {

cli/command/image/list_test.go

@@ -24,7 +24,7 @@ func TestNewImagesCommandErrors(t *testing.T) {
 		{
 			name:          "wrong-args",
 			args:          []string{"arg1", "arg2"},
-			expectedError: "requires at most 1 argument.",
+			expectedError: "requires at most 1 argument",
 		},
 		{
 			name:          "failed-list",

cli/command/image/load_test.go

@@ -24,7 +24,7 @@ func TestNewLoadCommandErrors(t *testing.T) {
 		{
 			name:          "wrong-args",
 			args:          []string{"arg"},
-			expectedError: "accepts no arguments.",
+			expectedError: "accepts no arguments",
 		},
 		{
 			name:          "input-to-terminal",

cli/command/image/prune_test.go

@@ -27,7 +27,7 @@ func TestNewPruneCommandErrors(t *testing.T) {
 		{
 			name:          "wrong-args",
 			args:          []string{"something"},
-			expectedError: "accepts no arguments.",
+			expectedError: "accepts no arguments",
 		},
 		{
 			name:          "prune-error",

cli/command/image/pull_test.go

@@ -23,7 +23,7 @@ func TestNewPullCommandErrors(t *testing.T) {
 	}{
 		{
 			name:          "wrong-args",
-			expectedError: "requires exactly 1 argument.",
+			expectedError: "requires 1 argument",
 			args:          []string{},
 		},
 		{

cli/command/image/push_test.go

@@ -21,7 +21,7 @@ func TestNewPushCommandErrors(t *testing.T) {
 		{
 			name:          "wrong-args",
 			args:          []string{},
-			expectedError: "requires exactly 1 argument.",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "invalid-name",

cli/command/image/remove_test.go

@@ -39,7 +39,7 @@ func TestNewRemoveCommandErrors(t *testing.T) {
 	}{
 		{
 			name:          "wrong args",
-			expectedError: "requires at least 1 argument.",
+			expectedError: "requires at least 1 argument",
 		},
 		{
 			name:          "ImageRemove fail with force option",

cli/command/image/save_test.go

@@ -23,7 +23,7 @@ func TestNewSaveCommandErrors(t *testing.T) {
 		{
 			name:          "wrong args",
 			args:          []string{},
-			expectedError: "requires at least 1 argument.",
+			expectedError: "requires at least 1 argument",
 		},
 		{
 			name:          "output to terminal",

cli/command/image/tag_test.go

@@ -15,7 +15,7 @@ func TestCliNewTagCommandErrors(t *testing.T) {
 		{"image1"},
 		{"image1", "image2", "image3"},
 	}
-	expectedError := "\"tag\" requires exactly 2 arguments."
+	expectedError := "'tag' requires 2 arguments"
 	for _, args := range testCases {
 		cmd := NewTagCommand(test.NewFakeCli(&fakeClient{}))
 		cmd.SetArgs(args)

cli/command/manifest/annotate_test.go

@@ -18,7 +18,7 @@ func TestManifestAnnotateError(t *testing.T) {
 	}{
 		{
 			args:          []string{"too-few-arguments"},
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args:          []string{"th!si'sa/fa!ke/li$t/name", "example.com/alpine:3.0"},

cli/command/manifest/push_test.go

@@ -31,7 +31,7 @@ func TestManifestPushErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{"one-arg", "extra-arg"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args:          []string{"th!si'sa/fa!ke/li$t/-name"},

cli/command/network/connect_test.go

@@ -19,7 +19,7 @@ func TestNetworkConnectErrors(t *testing.T) {
 		expectedError      string
 	}{
 		{
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args: []string{"toto", "titi"},

cli/command/network/create_test.go

@@ -21,7 +21,7 @@ func TestNetworkCreateErrors(t *testing.T) {
 		expectedError     string
 	}{
 		{
-			expectedError: "exactly 1 argument",
+			expectedError: "1 argument",
 		},
 		{
 			args: []string{"toto"},

cli/command/network/disconnect_test.go

@@ -17,7 +17,7 @@ func TestNetworkDisconnectErrors(t *testing.T) {
 		expectedError         string
 	}{
 		{
-			expectedError: "requires exactly 2 arguments",
+			expectedError: "requires 2 arguments",
 		},
 		{
 			args: []string{"toto", "titi"},

cli/command/node/update_test.go

@@ -20,11 +20,11 @@ func TestNodeUpdateErrors(t *testing.T) {
 		expectedError   string
 	}{
 		{
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args:          []string{"node1", "node2"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args: []string{"nodeID"},

cli/command/plugin/disable_test.go

@@ -19,11 +19,11 @@ func TestPluginDisableErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args:          []string{"too", "many", "arguments"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args:          []string{"plugin-foo"},

cli/command/plugin/enable_test.go

@@ -20,11 +20,11 @@ func TestPluginEnableErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args:          []string{"too-many", "arguments"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args: []string{"plugin-foo"},

cli/command/secret/remove_test.go

@@ -20,7 +20,7 @@ func TestSecretRemoveErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{},
-			expectedError: "requires at least 1 argument.",
+			expectedError: "requires at least 1 argument",
 		},
 		{
 			args: []string{"foo"},

cli/command/service/rollback_test.go

@@ -65,12 +65,12 @@ func TestRollbackWithErrors(t *testing.T) {
 	}{
 		{
 			name:          "not-enough-args",
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "too-many-args",
 			args:          []string{"service-id-1", "service-id-2"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name: "service-does-not-exists",

cli/command/stack/ps_test.go

@@ -24,11 +24,11 @@ func TestStackPsErrors(t *testing.T) {
 	}{
 		{
 			args:          []string{},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args:          []string{"foo", "bar"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			args: []string{"foo"},

cli/command/swarm/join_test.go

@@ -23,12 +23,12 @@ func TestSwarmJoinErrors(t *testing.T) {
 	}{
 		{
 			name:          "not-enough-args",
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "too-many-args",
 			args:          []string{"remote1", "remote2"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name: "join-failed",

cli/command/swarm/join_token_test.go

@@ -27,12 +27,12 @@ func TestSwarmJoinTokenErrors(t *testing.T) {
 	}{
 		{
 			name:          "not-enough-args",
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "too-many-args",
 			args:          []string{"worker", "manager"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "invalid-args",

cli/command/trust/key_generate_test.go

@@ -26,12 +26,12 @@ func TestTrustKeyGenerateErrors(t *testing.T) {
 	}{
 		{
 			name:          "not-enough-args",
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "too-many-args",
 			args:          []string{"key-1", "key-2"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 	}
 

cli/command/trust/key_load_test.go

@@ -34,13 +34,14 @@ func TestTrustKeyLoadErrors(t *testing.T) {
 	}{
 		{
 			name:           "not-enough-args",
-			expectedError:  "exactly 1 argument",
+			expectedError:  "1 argument",
+			args:           []string{},
 			expectedOutput: "",
 		},
 		{
 			name:           "too-many-args",
 			args:           []string{"iamnotakey", "alsonotakey"},
-			expectedError:  "exactly 1 argument",
+			expectedError:  "1 argument",
 			expectedOutput: "",
 		},
 		{

cli/command/trust/revoke_test.go

@@ -24,12 +24,12 @@ func TestTrustRevokeCommandErrors(t *testing.T) {
 	}{
 		{
 			name:          "not-enough-args",
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "too-many-args",
 			args:          []string{"remote1", "remote2"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "sha-reference",

cli/command/trust/sign_test.go

@@ -32,12 +32,12 @@ func TestTrustSignCommandErrors(t *testing.T) {
 	}{
 		{
 			name:          "not-enough-args",
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "too-many-args",
 			args:          []string{"image", "tag"},
-			expectedError: "requires exactly 1 argument",
+			expectedError: "requires 1 argument",
 		},
 		{
 			name:          "sha-reference",

cli/required.go

@@ -22,11 +22,10 @@ func NoArgs(cmd *cobra.Command, args []string) error {
 	}
 
 	return errors.Errorf(
-		"%q accepts no arguments.\nSee '%s --help'.\n\nUsage:  %s\n\n%s",
-		cmd.CommandPath(),
+		"%[1]s: '%[2]s' accepts no arguments\n\nUsage:  %[3]s\n\nRun '%[2]s --help' for more information",
+		binName(cmd),
 		cmd.CommandPath(),
 		cmd.UseLine(),
-		cmd.Short,
 	)
 }
 
@@ -37,13 +36,12 @@ func RequiresMinArgs(min int) cobra.PositionalArgs {
 			return nil
 		}
 		return errors.Errorf(
-			"%q requires at least %d %s.\nSee '%s --help'.\n\nUsage:  %s\n\n%s",
+			"%[1]s: '%[2]s' requires at least %[3]d %[4]s\n\nUsage:  %[5]s\n\nSee '%[2]s --help' for more information",
+			binName(cmd),
 			cmd.CommandPath(),
 			min,
 			pluralize("argument", min),
-			cmd.CommandPath(),
 			cmd.UseLine(),
-			cmd.Short,
 		)
 	}
 }
@@ -55,13 +53,12 @@ func RequiresMaxArgs(max int) cobra.PositionalArgs {
 			return nil
 		}
 		return errors.Errorf(
-			"%q requires at most %d %s.\nSee '%s --help'.\n\nUsage:  %s\n\n%s",
+			"%[1]s: '%[2]s' requires at most %[3]d %[4]s\n\nUsage:  %[5]s\n\nSRun '%[2]s --help' for more information",
+			binName(cmd),
 			cmd.CommandPath(),
 			max,
 			pluralize("argument", max),
-			cmd.CommandPath(),
 			cmd.UseLine(),
-			cmd.Short,
 		)
 	}
 }
@@ -73,14 +70,13 @@ func RequiresRangeArgs(min int, max int) cobra.PositionalArgs {
 			return nil
 		}
 		return errors.Errorf(
-			"%q requires at least %d and at most %d %s.\nSee '%s --help'.\n\nUsage:  %s\n\n%s",
+			"%[1]s: '%[2]s' requires at least %[3]d and at most %[4]d %[5]s\n\nUsage:  %[6]s\n\nRun '%[2]s --help' for more information",
+			binName(cmd),
 			cmd.CommandPath(),
 			min,
 			max,
 			pluralize("argument", max),
-			cmd.CommandPath(),
 			cmd.UseLine(),
-			cmd.Short,
 		)
 	}
 }
@@ -92,13 +88,12 @@ func ExactArgs(number int) cobra.PositionalArgs {
 			return nil
 		}
 		return errors.Errorf(
-			"%q requires exactly %d %s.\nSee '%s --help'.\n\nUsage:  %s\n\n%s",
+			"%[1]s: '%[2]s' requires %[3]d %[4]s\n\nUsage:  %[5]s\n\nRun '%[2]s --help' for more information",
+			binName(cmd),
 			cmd.CommandPath(),
 			number,
 			pluralize("argument", number),
-			cmd.CommandPath(),
 			cmd.UseLine(),
-			cmd.Short,
 		)
 	}
 }

cli/required_test.go

@@ -18,7 +18,7 @@ func TestRequiresNoArgs(t *testing.T) {
 		{
 			args:          []string{"foo"},
 			validateFunc:  NoArgs,
-			expectedError: "accepts no arguments.",
+			expectedError: "accepts no arguments",
 		},
 	}
 	for _, tc := range testCases {
@@ -36,12 +36,12 @@ func TestRequiresMinArgs(t *testing.T) {
 		},
 		{
 			validateFunc:  RequiresMinArgs(1),
-			expectedError: "at least 1 argument.",
+			expectedError: "at least 1 argument",
 		},
 		{
 			args:          []string{"foo"},
 			validateFunc:  RequiresMinArgs(2),
-			expectedError: "at least 2 arguments.",
+			expectedError: "at least 2 arguments",
 		},
 	}
 	for _, tc := range testCases {
@@ -60,12 +60,12 @@ func TestRequiresMaxArgs(t *testing.T) {
 		{
 			args:          []string{"foo", "bar"},
 			validateFunc:  RequiresMaxArgs(1),
-			expectedError: "at most 1 argument.",
+			expectedError: "at most 1 argument",
 		},
 		{
 			args:          []string{"foo", "bar", "baz"},
 			validateFunc:  RequiresMaxArgs(2),
-			expectedError: "at most 2 arguments.",
+			expectedError: "at most 2 arguments",
 		},
 	}
 	for _, tc := range testCases {
@@ -88,12 +88,12 @@ func TestRequiresRangeArgs(t *testing.T) {
 		{
 			args:          []string{"foo", "bar"},
 			validateFunc:  RequiresRangeArgs(0, 1),
-			expectedError: "at most 1 argument.",
+			expectedError: "at most 1 argument",
 		},
 		{
 			args:          []string{"foo", "bar", "baz"},
 			validateFunc:  RequiresRangeArgs(0, 2),
-			expectedError: "at most 2 arguments.",
+			expectedError: "at most 2 arguments",
 		},
 		{
 			validateFunc:  RequiresRangeArgs(1, 2),
@@ -115,11 +115,11 @@ func TestExactArgs(t *testing.T) {
 		},
 		{
 			validateFunc:  ExactArgs(1),
-			expectedError: "exactly 1 argument.",
+			expectedError: "1 argument",
 		},
 		{
 			validateFunc:  ExactArgs(2),
-			expectedError: "exactly 2 arguments.",
+			expectedError: "2 arguments",
 		},
 	}
 	for _, tc := range testCases {

cmd/docker/docker_test.go

@@ -66,7 +66,7 @@ func TestExitStatusForInvalidSubcommandWithHelpFlag(t *testing.T) {
 
 func TestExitStatusForInvalidSubcommand(t *testing.T) {
 	err := runCliCommand(t, nil, nil, "invalid")
-	assert.Check(t, is.ErrorContains(err, "docker: 'docker invalid' is not a docker command."))
+	assert.Check(t, is.ErrorContains(err, "docker: unknown command: docker invalid"))
 }
 
 func TestVersion(t *testing.T) {

e2e/cli-plugins/flags_test.go

@@ -180,14 +180,14 @@ func TestCliPluginsVersion(t *testing.T) {
 			args:    []string{"version", "foo"},
 			expCode: 1,
 			expOut:  icmd.None,
-			expErr:  `"docker version" accepts no arguments.`,
+			expErr:  `docker: 'docker version' accepts no arguments`,
 		},
 		{
 			name:    "global-with-plugin-arg",
 			args:    []string{"version", "helloworld"},
 			expCode: 1,
 			expOut:  icmd.None,
-			expErr:  `"docker version" accepts no arguments.`,
+			expErr:  `docker: 'docker version' accepts no arguments`,
 		},
 		{
 			name:    "global-version-flag-with-unknown-arg",