Begin introducing alternate runtime "argh mode"

Connected to #1583

cli.go

@@ -30,7 +30,8 @@ import (
 )
 
 var (
- isTracingOn = os.Getenv("URFAVE_CLI_TRACING") == "on"
+ isTracingOn = os.Getenv("URFAVE_CLI_TRACING") == "on"
+ isArghModeOn = os.Getenv("URFAVE_CLI_ARGH_MODE") == "on"
 )
 
 func tracef(format string, a ...any) {

command.go

@@ -2,6 +2,7 @@ package cli
 
 import (
  "context"
+ "encoding/json"
  "flag"
  "fmt"
  "io"
@@ -10,6 +11,8 @@ import (
  "reflect"
  "sort"
  "strings"
+
+ "github.com/urfave/argh"
 )
 
 const (
@@ -139,6 +142,12 @@ type Command struct {
  isInError bool
  // track state of defaults
  didSetupDefaults bool
+
+ // fields used by argh-based parsing {{
+ parserCfg *argh.ParserConfig
+ cfg *argh.CommandConfig
+ stringValues map[string]string
+ // }}
 }
 
 // FullName returns the full name of the command.
@@ -175,6 +184,16 @@ func (cmd *Command) setupDefaults(osArgs []string) {
  isRoot := cmd.parent == nil
  tracef("isRoot? %[1]v (cmd=%[2]q)", isRoot, cmd.Name)
 
+ if isArghModeOn {
+ if isRoot {
+ cmd.parserCfg = argh.NewParserConfig()
+ cmd.cfg = cmd.parserCfg.Prog
+ cmd.cfg.NValue = argh.ZeroOrMoreValue
+ }
+
+ cmd.stringValues = map[string]string{}
+ }
+
  if cmd.ShellComplete == nil {
  tracef("setting default ShellComplete (cmd=%[1]q)", cmd.Name)
  cmd.ShellComplete = DefaultCompleteWithFlags(cmd)
@@ -287,6 +306,49 @@ func (cmd *Command) setupDefaults(osArgs []string) {
  disableSliceFlagSeparator = cmd.DisableSliceFlagSeparator
 }
 
+func (cmd *Command) setupParser() {
+ tracef("setting up parser (cmd=%[1]q)", cmd.Name)
+
+ // TODO: add support for named positional args {{
+ cmd.cfg.NValue = 1
+ cmd.cfg.ValueNames = []string{}
+ // }}
+
+ for _, loopFlag := range cmd.Flags {
+ fl := loopFlag
+
+ // TODO: add support for flags with value counts other than 0 and 1
+ flagNValue := argh.NValue(0)
+ canonicalName := fl.Names()[0]
+
+ if v, ok := fl.(DocGenerationFlag); ok && v.TakesValue() {
+ flagNValue = argh.NValue(1)
+ canonicalName = v.CanonicalName()
+ }
+
+ flCfg := &argh.FlagConfig{
+ NValue: flagNValue,
+ On: func(cf argh.CommandFlag) {
+ tracef("flag %[1]q set (cmd=%[2]q)", fl.Names(), cmd.Name)
+
+ for k, v := range cf.Values {
+ cmd.stringValues[fmt.Sprintf("%[1]v.%[2]v", canonicalName, cf.Name, k)] = v
+ }
+ },
+ }
+
+ for _, name := range fl.Names() {
+ tracef("setting flag config in parser config name=%[1]q cfg=%+#[2]v flCfg=%+#[3]v (cmd=%[4]q)", name, cmd.cfg, flCfg, cmd.Name)
+
+ cmd.cfg.SetFlagConfig(name, flCfg)
+ }
+ }
+
+ for _, subCmd := range cmd.Commands {
+ subCmd.setupParser()
+ }
+}
+
 func (cmd *Command) setupCommandGraph() {
  tracef("setting up command graph (cmd=%[1]q)", cmd.Name)
 
@@ -300,6 +362,21 @@ func (cmd *Command) setupCommandGraph() {
 func (cmd *Command) setupSubcommand() {
  tracef("setting up self as sub-command (cmd=%[1]q)", cmd.Name)
 
+ if isArghModeOn {
+ cfg, ok := cmd.parent.cfg.GetCommandConfig(cmd.Name)
+ if !ok {
+ cfg = argh.CommandConfig{}
+ }
+
+ cfg.On = func(cf argh.CommandFlag) {
+ tracef("received command flag=%+#[1]v (cmd=%[2]q)", cmd.Name)
+ }
+
+ tracef("setting parser config on parent cfg=%+#[1]v (cmd=%[2]q)", &cfg, cmd.Name)
+ cmd.parent.cfg.SetCommandConfig(cmd.Name, &cfg)
+ cmd.cfg = &cfg
+ }
+
  cmd.ensureHelp()
 
  tracef("setting command categories (cmd=%[1]q)", cmd.Name)
@@ -338,6 +415,15 @@ func (cmd *Command) ensureHelp() {
 // arguments are parsed according to the Flag and Command
 // definitions and the matching Action functions are run.
 func (cmd *Command) Run(ctx context.Context, osArgs []string) (deferErr error) {
+ if isArghModeOn {
+ if err := cmd.runWithArgh(ctx, osArgs); err != nil {
+ tracef("setting deferErr from argh error: %[1]v", err)
+ deferErr = err
+ }
+
+ return
+ }
+
  tracef("running with arguments %[1]q (cmd=%[2]q)", osArgs, cmd.Name)
  cmd.setupDefaults(osArgs)
 
@@ -524,6 +610,44 @@ func (cmd *Command) Run(ctx context.Context, osArgs []string) (deferErr error) {
  return deferErr
 }
 
+func (cmd *Command) runWithArgh(ctx context.Context, osArgs []string) error {
+ cmd.setupParser()
+
+ parseTree, parseErr := argh.ParseArgs(osArgs, cmd.Root().parserCfg)
+ if parseErr != nil {
+ tracef("argh parse error: %[1]v", parseErr)
+
+ return parseErr
+ }
+
+ if isTracingOn {
+ if b, err := json.Marshal(argh.ToAST(parseTree.Nodes)); err == nil {
+ tracef("argh ast: %[1]s", string(b))
+ }
+
+ if v, ok := os.LookupEnv("URFAVE_CLI_ARGH_DUMP_JSON"); ok {
+ if fd, err := os.Create(v); err == nil {
+ if err := json.NewEncoder(fd).Encode(
+ map[string]any{
+ "cfg": cmd.cfg,
+ "string_values": cmd.stringValues,
+ "ast": argh.ToAST(parseTree.Nodes),
+ "err": parseErr,
+ },
+ ); err != nil {
+ tracef("URFAVE_CLI_ARGH_DUMP_JSON err: %[1]v", err)
+ }
+
+ if err := fd.Close(); err != nil {
+ tracef("URFAVE_CLI_ARGH_DUMP_JSON err: %[1]v", err)
+ }
+ }
+ }
+ }
+
+ return nil
+}
+
 func (cmd *Command) checkHelp() bool {
  tracef("checking if help is wanted (cmd=%[1]q)", cmd.Name)
 

flag.go

@@ -123,6 +123,8 @@ type DocGenerationFlag interface {
  // TakesValue returns true if the flag takes a value, otherwise false
  TakesValue() bool
 
+ CanonicalName() string
+
  // GetUsage returns the usage string for the flag
  GetUsage() string
 

flag_impl.go

@@ -210,6 +210,10 @@ func (f *FlagBase[T, C, V]) IsSet() bool {
  return f.hasBeenSet
 }
 
+func (f *FlagBase[T, C, V]) CanonicalName() string {
+ return f.Name
+}
+
 // Names returns the names of the flag
 func (f *FlagBase[T, C, V]) Names() []string {
  return FlagNames(f.Name, f.Aliases)

go.mod

@@ -4,6 +4,7 @@ go 1.18
 
 require (
  github.com/stretchr/testify v1.8.4
+ github.com/urfave/argh v0.2.1-0.20230702123329-da1ca8be8db5
  github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673
 )
 

go.sum

@@ -4,6 +4,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/urfave/argh v0.2.1-0.20230702123329-da1ca8be8db5 h1:Wlo6nZHECi5IysPUZKOq8KN8AoT/6KsmdGBRidH6n1M=
+github.com/urfave/argh v0.2.1-0.20230702123329-da1ca8be8db5/go.mod h1:NUm2NMpNFfFIzbpD9qe98ZL7G3TYWiH1bynhvbJw2pY=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=

godoc-current.txt

@@ -516,6 +516,8 @@ type DocGenerationFlag interface {
  // TakesValue returns true if the flag takes a value, otherwise false
  TakesValue() bool
 
+ CanonicalName() string
+
  // GetUsage returns the usage string for the flag
  GetUsage() string
 
@@ -645,6 +647,8 @@ type FlagBase[T any, C any, VC ValueCreator[T, C]] struct {
 func (f *FlagBase[T, C, V]) Apply(set *flag.FlagSet) error
  Apply populates the flag given the flag set and environment
 
+func (f *FlagBase[T, C, V]) CanonicalName() string
+
 func (f *FlagBase[T, C, V]) Get(cmd *Command) T
  Get returns the flag’s value in the given Command.
 

testdata/godoc-v3.x.txt

@@ -516,6 +516,8 @@ type DocGenerationFlag interface {
  // TakesValue returns true if the flag takes a value, otherwise false
  TakesValue() bool
 
+ CanonicalName() string
+
  // GetUsage returns the usage string for the flag
  GetUsage() string
 
@@ -645,6 +647,8 @@ type FlagBase[T any, C any, VC ValueCreator[T, C]] struct {
 func (f *FlagBase[T, C, V]) Apply(set *flag.FlagSet) error
  Apply populates the flag given the flag set and environment
 
+func (f *FlagBase[T, C, V]) CanonicalName() string
+
 func (f *FlagBase[T, C, V]) Get(cmd *Command) T
  Get returns the flag’s value in the given Command.