fix: support any flags order

This change contains the minimum change required to support some of the requirements described in gnolang#731

What it brings:
- Fork of `ffcli` in `tm2/pkg/commands/ffcli`. Note that the legacy `ff` is still used (so env var and config file override is still supported).
- Accepts flags declared after the command arguments.
This is one of the main complaints about `ffcli`. Now use can run `
-

tm2/pkg/commands/command.go

@@ -55,7 +55,7 @@ func NewCommand(
 			LongHelp:   meta.LongHelp,
 			ShortUsage: meta.ShortUsage,
 			Options:    meta.Options,
-			FlagSet:    flag.NewFlagSet(meta.Name, flag.ExitOnError),
+			FlagSet:    flag.NewFlagSet(meta.Name, flag.ContinueOnError),
 			Exec:       exec,
 		},
 		cfg: config,

tm2/pkg/commands/commands_test.go

@@ -1,11 +1,14 @@
 package commands
 
 import (
+	"context"
 	"flag"
 	"testing"
 
-	"github.com/gnolang/gno/tm2/pkg/commands/ffcli"
+	"github.com/jaekwon/testify/require"
 	"github.com/stretchr/testify/assert"
+
+	"github.com/gnolang/gno/tm2/pkg/commands/ffcli"
 )
 
 type configDelegate func(*flag.FlagSet)
@@ -20,6 +23,164 @@ func (c *mockConfig) RegisterFlags(fs *flag.FlagSet) {
 	}
 }
 
+func TestCommandFlagsOrder(t *testing.T) {
+	type flags struct {
+		b bool
+		s string
+		x bool
+	}
+	tests := []struct {
+		name          string
+		osArgs        []string
+		expectedArgs  []string
+		expectedFlags flags
+		expectedError string
+	}{
+		{
+			name:          "no args no flags",
+			osArgs:        []string{},
+			expectedArgs:  []string{},
+			expectedFlags: flags{},
+		},
+		{
+			name:          "only args",
+			osArgs:        []string{"bar", "baz"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{},
+		},
+		{
+			name:          "only flags",
+			osArgs:        []string{"-b", "-s", "str"},
+			expectedArgs:  []string{},
+			expectedFlags: flags{b: true, s: "str"},
+		},
+		{
+			name:          "unknow flag",
+			osArgs:        []string{"-y", "-s", "str"},
+			expectedArgs:  []string{},
+			expectedError: "error parsing commandline arguments: flag provided but not defined: -y",
+		},
+		{
+			name:          "flags before args",
+			osArgs:        []string{"-b", "-s", "str", "bar", "baz"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{b: true, s: "str"},
+		},
+		{
+			name:          "flags after args",
+			osArgs:        []string{"bar", "baz", "-b", "-s", "str"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{b: true, s: "str"},
+		},
+		{
+			name:          "flags around args",
+			osArgs:        []string{"-b", "bar", "baz", "-s", "str"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{b: true, s: "str"},
+		},
+		{
+			name:          "flags between args",
+			osArgs:        []string{"bar", "-b", "-s", "str", "baz"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{b: true, s: "str"},
+		},
+		{
+			name:          "subcommand no flags no args",
+			osArgs:        []string{"sub"},
+			expectedArgs:  []string{},
+			expectedFlags: flags{},
+		},
+		{
+			name:          "subcommand only args",
+			osArgs:        []string{"sub", "bar", "baz"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{},
+		},
+		{
+			name:          "subcommand flag before subcommand",
+			osArgs:        []string{"-x", "sub"},
+			expectedError: "error parsing commandline arguments: flag provided but not defined: -x",
+		},
+		{
+			name:          "subcommand only flags",
+			osArgs:        []string{"-b", "sub", "-x", "-s", "str"},
+			expectedArgs:  []string{},
+			expectedFlags: flags{b: true, s: "str", x: true},
+		},
+		{
+			name:          "subcommand flags before args",
+			osArgs:        []string{"-b", "sub", "-x", "-s", "str", "bar", "baz"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{b: true, s: "str", x: true},
+		},
+		{
+			name:          "subcommand flags after args",
+			osArgs:        []string{"-b", "sub", "bar", "baz", "-x", "-s", "str"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{b: true, s: "str", x: true},
+		},
+		{
+			name:          "subcommand flags around args",
+			osArgs:        []string{"-b", "sub", "-x", "bar", "baz", "-s", "str"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{b: true, s: "str", x: true},
+		},
+		{
+			name:          "subcommand flags between args",
+			osArgs:        []string{"-b", "sub", "bar", "-x", "baz", "-s", "str"},
+			expectedArgs:  []string{"bar", "baz"},
+			expectedFlags: flags{b: true, s: "str", x: true},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var (
+				args  []string
+				flags flags
+			)
+			// Create a cmd main that takes 2 flags -b and -s
+			cmd := NewCommand(
+				Metadata{Name: "main"},
+				&mockConfig{
+					configFn: func(fs *flag.FlagSet) {
+						fs.BoolVar(&flags.b, "b", false, "a boolan")
+						fs.StringVar(&flags.s, "s", "", "a string")
+					},
+				},
+				func(_ context.Context, a []string) error {
+					args = a
+					return nil
+				},
+			)
+			// Add a sub command to cmd with a single flag -x
+			cmd.AddSubCommands(
+				NewCommand(
+					Metadata{Name: "sub"},
+					&mockConfig{
+						configFn: func(fs *flag.FlagSet) {
+							fs.BoolVar(&flags.x, "x", false, "a boolan")
+						},
+					},
+					func(_ context.Context, a []string) error {
+						args = a
+						return nil
+					},
+				),
+			)
+
+			err := cmd.ParseAndRun(context.Background(), tt.osArgs)
+
+			if tt.expectedError != "" {
+				require.EqualError(t, err, tt.expectedError)
+				return
+			}
+			require.NoError(t, err)
+			require.Equal(t, args, tt.expectedArgs, "wrong args")
+			require.Equal(t, flags, tt.expectedFlags, "wrong flags")
+		})
+	}
+}
+
 func TestCommand_AddSubCommands(t *testing.T) {
 	t.Parallel()
 

tm2/pkg/commands/ffcli/command.go

@@ -116,6 +116,19 @@ func (c *Command) Parse(args []string) error {
 				return subcommand.Parse(c.args[1:])
 			}
 		}
+		// args[0] is not a sub command, so it's an command argument.
+		c.args = c.args[:1]
+		// continue flag parsing after args[0]
+		for c.FlagSet.NArg() > 1 {
+			err := ff.Parse(c.FlagSet, c.FlagSet.Args()[1:], c.Options...)
+			if err != nil {
+				return err
+			}
+			if c.FlagSet.NArg() > 0 {
+				// Arg(0) is an arg, not a flag
+				c.args = append(c.args, c.FlagSet.Arg(0))
+			}
+		}
 	}
 
 	c.selected = c