feat: improve missing argument error messages

CONTRIBUTING.md

@@ -139,8 +139,30 @@ Additional Commands:
   ssh                         Spawn an SSH connection for the server
 ```
 
+### Command validation
+
+Please use the `util.Validate` method to make sure the command is validated against its usage string during runtime.
+This can be done by setting the `Args` field of the `cobra.Command` struct to `util.Validate`:
+
+```go
+cmd := &cobra.Command{
+   Use:   "my-command [options]",
+   Args:  util.Validate,
+   Run: func(cmd *cobra.Command, args []string) {
+      // ...
+   },
+}
+```
+
+If you are using base commands like `base.Cmd` or `base.ListCmd` etc., this is already done for you.
+
+**Note:** Your command usage needs to follow the [docopt](http://docopt.org/) syntax for this to work.
+If your command uses optional positional arguments or other complicated usage that necessitates to disable
+argument count checking, you use `util.ValidateLenient` instead. It will not throw an error if there are
+more arguments than expected.
+
 ### Generated files
 
-Generated files (that are created by running `go generate`) should be prefixed with `zz_`. This is to group them 
+Generated files (that are created by running `go generate`) should be prefixed with `zz_`. This is to group them
 together in the file list and to easily identify them as generated files. Also, it allows the CI to check if the
 generated files are up-to-date.

internal/cmd/all/all.go

@@ -3,14 +3,15 @@ package all
 import (
 	"github.com/spf13/cobra"
 
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 )
 
 func NewCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "all",
 		Short:                 "Commands that apply to all resources",
-		Args:                  cobra.NoArgs,
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 	}

internal/cmd/base/cmd.go

@@ -19,7 +19,7 @@ func (gc *Cmd) CobraCommand(s state.State) *cobra.Command {
 	cmd := gc.BaseCobraCommand(s.Client())
 
 	if cmd.Args == nil {
-		cmd.Args = cobra.NoArgs
+		cmd.Args = util.Validate
 	}
 
 	cmd.TraverseChildren = true

internal/cmd/base/create.go

@@ -27,7 +27,7 @@ func (cc *CreateCmd) CobraCommand(s state.State) *cobra.Command {
 	output.AddFlag(cmd, output.OptionJSON(), output.OptionYAML())
 
 	if cmd.Args == nil {
-		cmd.Args = cobra.NoArgs
+		cmd.Args = util.Validate
 	}
 
 	cmd.TraverseChildren = true

internal/cmd/base/delete.go

@@ -3,7 +3,6 @@ package base
 import (
 	"fmt"
 	"reflect"
-	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -32,9 +31,9 @@ func (dc *DeleteCmd) CobraCommand(s state.State) *cobra.Command {
 	}
 
 	cmd := &cobra.Command{
-		Use:                   fmt.Sprintf("delete %s<%s>", opts, strings.ToLower(dc.ResourceNameSingular)),
+		Use:                   fmt.Sprintf("delete %s<%s>", opts, util.ToKebabCase(dc.ResourceNameSingular)),
 		Short:                 dc.ShortDescription,
-		Args:                  cobra.ExactArgs(1),
+		Args:                  util.Validate,
 		ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(dc.NameSuggestions(s.Client()))),
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,

internal/cmd/base/describe.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"os"
 	"reflect"
-	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -33,9 +32,9 @@ type DescribeCmd struct {
 // CobraCommand creates a command that can be registered with cobra.
 func (dc *DescribeCmd) CobraCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
-		Use:                   fmt.Sprintf("describe [options] <%s>", strings.ToLower(dc.ResourceNameSingular)),
+		Use:                   fmt.Sprintf("describe [options] <%s>", util.ToKebabCase(dc.ResourceNameSingular)),
 		Short:                 dc.ShortDescription,
-		Args:                  cobra.ExactArgs(1),
+		Args:                  util.Validate,
 		ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(dc.NameSuggestions(s.Client()))),
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,

internal/cmd/base/labels.go

@@ -27,9 +27,9 @@ type LabelCmds struct {
 // AddCobraCommand creates a command that can be registered with cobra.
 func (lc *LabelCmds) AddCobraCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
-		Use:                   fmt.Sprintf("add-label [--overwrite] <%s> <label>...", strings.ToLower(lc.ResourceNameSingular)),
+		Use:                   fmt.Sprintf("add-label [--overwrite] <%s> <label>...", util.ToKebabCase(lc.ResourceNameSingular)),
 		Short:                 lc.ShortDescriptionAdd,
-		Args:                  cobra.MinimumNArgs(2),
+		Args:                  util.Validate,
 		ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(lc.NameSuggestions(s.Client()))),
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
@@ -89,9 +89,9 @@ func validateAddLabel(_ *cobra.Command, args []string) error {
 // RemoveCobraCommand creates a command that can be registered with cobra.
 func (lc *LabelCmds) RemoveCobraCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
-		Use:   fmt.Sprintf("remove-label <%s> (--all | <label>...)", strings.ToLower(lc.ResourceNameSingular)),
+		Use:   fmt.Sprintf("remove-label <%s> (--all | <label>...)", util.ToKebabCase(lc.ResourceNameSingular)),
 		Short: lc.ShortDescriptionRemove,
-		Args:  cobra.MinimumNArgs(1),
+		Args:  util.ValidateLenient,
 		ValidArgsFunction: cmpl.SuggestArgs(
 			cmpl.SuggestCandidatesF(lc.NameSuggestions(s.Client())),
 			cmpl.SuggestCandidatesCtx(func(_ *cobra.Command, args []string) []string {

internal/cmd/base/list.go

@@ -35,6 +35,7 @@ func (lc *ListCmd) CobraCommand(s state.State) *cobra.Command {
 			fmt.Sprintf("Displays a list of %s.", lc.ResourceNamePlural),
 			outputColumns,
 		),
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 		PreRunE:               s.EnsureToken,

internal/cmd/base/set_rdns.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"net"
 	"reflect"
-	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -28,9 +27,9 @@ type SetRdnsCmd struct {
 // CobraCommand creates a command that can be registered with cobra.
 func (rc *SetRdnsCmd) CobraCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
-		Use:                   fmt.Sprintf("set-rdns [options] --hostname <hostname> <%s>", strings.ToLower(rc.ResourceNameSingular)),
+		Use:                   fmt.Sprintf("set-rdns [options] --hostname <hostname> <%s>", util.ToKebabCase(rc.ResourceNameSingular)),
 		Short:                 rc.ShortDescription,
-		Args:                  cobra.ExactArgs(1),
+		Args:                  util.Validate,
 		ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(rc.NameSuggestions(s.Client()))),
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,

internal/cmd/base/update.go

@@ -3,7 +3,6 @@ package base
 import (
 	"fmt"
 	"reflect"
-	"strings"
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
@@ -28,9 +27,9 @@ type UpdateCmd struct {
 // CobraCommand creates a command that can be registered with cobra.
 func (uc *UpdateCmd) CobraCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
-		Use:                   fmt.Sprintf("update [options] <%s>", strings.ToLower(uc.ResourceNameSingular)),
+		Use:                   fmt.Sprintf("update [options] <%s>", util.ToKebabCase(uc.ResourceNameSingular)),
 		Short:                 uc.ShortDescription,
-		Args:                  cobra.ExactArgs(1),
+		Args:                  util.Validate,
 		ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(uc.NameSuggestions(s.Client()))),
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,

internal/cmd/certificate/certificate.go

@@ -3,14 +3,15 @@ package certificate
 import (
 	"github.com/spf13/cobra"
 
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 )
 
 func NewCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "certificate",
 		Short:                 "Manage certificates",
-		Args:                  cobra.NoArgs,
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 	}

internal/cmd/certificate/create.go

@@ -19,7 +19,6 @@ var CreateCmd = base.CreateCmd{
 		cmd := &cobra.Command{
 			Use:   "create [options] --name <name> (--type managed --domain <domain> | --type uploaded --cert-file <file> --key-file <file>)",
 			Short: "Create or upload a Certificate",
-			Args:  cobra.ExactArgs(0),
 		}
 
 		cmd.Flags().String("name", "", "Certificate name (required)")

internal/cmd/completion/completion.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 )
 
@@ -94,7 +95,7 @@ and source this file from your PowerShell profile.
 
   PS> hcloud completion powershell > hcloud.ps1
 `,
-		Args:                  cobra.ExactArgs(1),
+		Args:                  util.Validate,
 		ValidArgs:             []string{"bash", "fish", "zsh", "powershell"},
 		DisableFlagsInUseLine: true,
 		RunE: func(cmd *cobra.Command, args []string) error {

internal/cmd/context/active.go

@@ -6,14 +6,15 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 )
 
 func newActiveCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "active",
 		Short:                 "Show active context",
-		Args:                  cobra.NoArgs,
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 		RunE:                  state.Wrap(s, runActive),

internal/cmd/context/context.go

@@ -3,14 +3,15 @@ package context
 import (
 	"github.com/spf13/cobra"
 
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 )
 
 func NewCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "context",
 		Short:                 "Manage contexts",
-		Args:                  cobra.NoArgs,
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 	}

internal/cmd/context/create.go

@@ -11,6 +11,7 @@ import (
 	"github.com/spf13/cobra"
 	"golang.org/x/term"
 
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 	"github.com/hetznercloud/cli/internal/state/config"
 )
@@ -19,7 +20,7 @@ func newCreateCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "create <name>",
 		Short:                 "Create a new context",
-		Args:                  cobra.ExactArgs(1),
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 		RunE:                  state.Wrap(s, runCreate),

internal/cmd/context/delete.go

@@ -7,6 +7,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/hetznercloud/cli/internal/cmd/cmpl"
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 	"github.com/hetznercloud/cli/internal/state/config"
 )
@@ -15,7 +16,7 @@ func newDeleteCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "delete <context>",
 		Short:                 "Delete a context",
-		Args:                  cobra.ExactArgs(1),
+		Args:                  util.Validate,
 		ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidates(config.ContextNames(s.Config())...)),
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,

internal/cmd/context/list.go

@@ -30,7 +30,7 @@ func newListCommand(s state.State) *cobra.Command {
 			"Displays a list of contexts.",
 			listTableOutput.Columns(),
 		),
-		Args:                  cobra.NoArgs,
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 		RunE:                  state.Wrap(s, runList),

internal/cmd/context/use.go

@@ -7,6 +7,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/hetznercloud/cli/internal/cmd/cmpl"
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 	"github.com/hetznercloud/cli/internal/state/config"
 )
@@ -15,7 +16,7 @@ func newUseCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "use <context>",
 		Short:                 "Use a context",
-		Args:                  cobra.ExactArgs(1),
+		Args:                  util.Validate,
 		ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidates(config.ContextNames(s.Config())...)),
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,

internal/cmd/datacenter/datacenter.go

@@ -3,14 +3,15 @@ package datacenter
 import (
 	"github.com/spf13/cobra"
 
+	"github.com/hetznercloud/cli/internal/cmd/util"
 	"github.com/hetznercloud/cli/internal/state"
 )
 
 func NewCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "datacenter",
 		Short:                 "Manage datacenters",
-		Args:                  cobra.NoArgs,
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 	}

internal/cmd/firewall/add_rule.go

@@ -18,7 +18,6 @@ var AddRuleCmd = base.Cmd{
 		cmd := &cobra.Command{
 			Use:                   "add-rule [options] (--direction in --source-ips <ips> | --direction out --destination-ips <ips>) --protocol <icmp|udp|tcp|esp|gre> <firewall>",
 			Short:                 "Add a single rule to a firewall",
-			Args:                  cobra.ExactArgs(1),
 			ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(client.Firewall().Names)),
 			TraverseChildren:      true,
 			DisableFlagsInUseLine: true,

internal/cmd/firewall/apply_to_resource.go

@@ -17,7 +17,6 @@ var ApplyToResourceCmd = base.Cmd{
 		cmd := &cobra.Command{
 			Use:                   "apply-to-resource (--type server --server <server> | --type label_selector --label-selector <label-selector>) <firewall>",
 			Short:                 "Applies a Firewall to a single resource",
-			Args:                  cobra.ExactArgs(1),
 			ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(client.Firewall().Names)),
 			TraverseChildren:      true,
 			DisableFlagsInUseLine: true,

internal/cmd/firewall/create.go

@@ -22,7 +22,6 @@ var CreateCmd = base.CreateCmd{
 		cmd := &cobra.Command{
 			Use:   "create [options] --name <name>",
 			Short: "Create a Firewall",
-			Args:  cobra.NoArgs,
 		}
 		cmd.Flags().String("name", "", "Name")
 		cmd.MarkFlagRequired("name")

internal/cmd/firewall/delete_rule.go

@@ -19,7 +19,6 @@ var DeleteRuleCmd = base.Cmd{
 		cmd := &cobra.Command{
 			Use:                   "delete-rule [options] (--direction in --source-ips <ips> | --direction out --destination-ips <ips>) --protocol <icmp|esp|gre|udp|tcp> <firewall>",
 			Short:                 "Delete a single rule to a firewall",
-			Args:                  cobra.ExactArgs(1),
 			ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(client.Firewall().Names)),
 			TraverseChildren:      true,
 			DisableFlagsInUseLine: true,

internal/cmd/firewall/firewall.go

@@ -11,7 +11,7 @@ func NewCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "firewall",
 		Short:                 "Manage Firewalls",
-		Args:                  cobra.NoArgs,
+		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
 	}

internal/cmd/firewall/remove_from_resource.go

@@ -17,7 +17,6 @@ var RemoveFromResourceCmd = base.Cmd{
 		cmd := &cobra.Command{
 			Use:                   "remove-from-resource (--type server --server <server> | --type label_selector --label-selector <label-selector>) <firewall>",
 			Short:                 "Removes a Firewall from a single resource",
-			Args:                  cobra.ExactArgs(1),
 			ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(client.Firewall().Names)),
 			TraverseChildren:      true,
 			DisableFlagsInUseLine: true,

internal/cmd/firewall/replace_rules.go

@@ -22,7 +22,6 @@ var ReplaceRulesCmd = base.Cmd{
 		cmd := &cobra.Command{
 			Use:                   "replace-rules --rules-file <file> <firewall>",
 			Short:                 "Replaces all rules from a Firewall from a file",
-			Args:                  cobra.ExactArgs(1),
 			ValidArgsFunction:     cmpl.SuggestArgs(cmpl.SuggestCandidatesF(client.Firewall().Names)),
 			TraverseChildren:      true,
 			DisableFlagsInUseLine: true,

internal/cmd/floatingip/assign.go

@@ -16,7 +16,6 @@ var AssignCmd = base.Cmd{
 		return &cobra.Command{
 			Use:   "assign <floating-ip> <server>",
 			Short: "Assign a Floating IP to a server",
-			Args:  cobra.ExactArgs(2),
 			ValidArgsFunction: cmpl.SuggestArgs(
 				cmpl.SuggestCandidatesF(client.FloatingIP().Names),
 				cmpl.SuggestCandidatesF(client.Server().Names),