From cef66fd2f6e0e061ade3778d3d3868032e4f0a32 Mon Sep 17 00:00:00 2001
From: Alexey Trofimov <dmzkrsk@gmail.com>
Date: Wed, 18 Jan 2023 11:50:50 +0300
Subject: [PATCH 1/2] add strict subcommand parsing

---
 go.sum        |  2 --
 parse.go      | 11 ++++++-
 parse_test.go | 82 +++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 89 insertions(+), 6 deletions(-)

diff --git a/go.sum b/go.sum
index 5b536f9..385ca8f 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,3 @@
-github.com/alexflint/go-scalar v1.1.0 h1:aaAouLLzI9TChcPXotr6gUhq+Scr8rl0P9P4PnltbhM=
-github.com/alexflint/go-scalar v1.1.0/go.mod h1:LoFvNMqS1CPrMVltza4LvnGKhaSpc3oyLEBUZVhhS2o=
 github.com/alexflint/go-scalar v1.2.0 h1:WR7JPKkeNpnYIOfHRa7ivM21aWAdHD0gEWHCx+WQBRw=
 github.com/alexflint/go-scalar v1.2.0/go.mod h1:LoFvNMqS1CPrMVltza4LvnGKhaSpc3oyLEBUZVhhS2o=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
diff --git a/parse.go b/parse.go
index 6ac5e99..3efe858 100644
--- a/parse.go
+++ b/parse.go
@@ -115,6 +115,10 @@ type Config struct {
 	// IgnoreDefault instructs the library not to reset the variables to the
 	// default values, including pointers to sub commands
 	IgnoreDefault bool
+
+	// IgnoreDefault intructs the library not to allow global commands after
+	// subcommand
+	StrictSubcommands bool
 }
 
 // Parser represents a set of command line options with destination values
@@ -588,7 +592,12 @@ func (p *Parser) process(args []string) error {
 			}
 
 			// add the new options to the set of allowed options
-			specs = append(specs, subcmd.specs...)
+			if p.config.StrictSubcommands {
+				specs = make([]*spec, len(subcmd.specs))
+				copy(specs, subcmd.specs)
+			} else {
+				specs = append(specs, subcmd.specs...)
+			}
 
 			// capture environment vars for these new options
 			if !p.config.IgnoreEnv {
diff --git a/parse_test.go b/parse_test.go
index 5d38306..64119a8 100644
--- a/parse_test.go
+++ b/parse_test.go
@@ -98,9 +98,9 @@ func TestInt(t *testing.T) {
 
 func TestHexOctBin(t *testing.T) {
 	var args struct {
-		Hex int
-		Oct int
-		Bin int
+		Hex         int
+		Oct         int
+		Bin         int
 		Underscored int
 	}
 	err := parse("--hex 0xA --oct 0o10 --bin 0b101 --underscored 123_456", &args)
@@ -1614,3 +1614,79 @@ func TestTextMarshalerUnmarshalerEmptyPointer(t *testing.T) {
 	require.NoError(t, err)
 	assert.Nil(t, args.Config)
 }
+
+func TestSubcommandGlobalFlag_Before(t *testing.T) {
+	var args struct {
+		Global bool `arg:"-g"`
+		Sub    *struct {
+		} `arg:"subcommand"`
+	}
+
+	p, err := NewParser(Config{StrictSubcommands: false}, &args)
+	require.NoError(t, err)
+
+	err = p.Parse([]string{"-g", "sub"})
+	assert.NoError(t, err)
+	assert.True(t, args.Global)
+}
+
+func TestSubcommandGlobalFlag_InCommand(t *testing.T) {
+	var args struct {
+		Global bool `arg:"-g"`
+		Sub    *struct {
+		} `arg:"subcommand"`
+	}
+
+	p, err := NewParser(Config{StrictSubcommands: false}, &args)
+	require.NoError(t, err)
+
+	err = p.Parse([]string{"sub", "-g"})
+	assert.NoError(t, err)
+	assert.True(t, args.Global)
+}
+
+func TestSubcommandGlobalFlag_Before_Strict(t *testing.T) {
+	var args struct {
+		Global bool `arg:"-g"`
+		Sub    *struct {
+		} `arg:"subcommand"`
+	}
+
+	p, err := NewParser(Config{StrictSubcommands: true}, &args)
+	require.NoError(t, err)
+
+	err = p.Parse([]string{"-g", "sub"})
+	assert.NoError(t, err)
+	assert.True(t, args.Global)
+}
+
+func TestSubcommandGlobalFlag_InCommand_Strict(t *testing.T) {
+	var args struct {
+		Global bool `arg:"-g"`
+		Sub    *struct {
+		} `arg:"subcommand"`
+	}
+
+	p, err := NewParser(Config{StrictSubcommands: true}, &args)
+	require.NoError(t, err)
+
+	err = p.Parse([]string{"sub", "-g"})
+	assert.Error(t, err)
+}
+
+func TestSubcommandGlobalFlag_InCommand_Strict_Inner(t *testing.T) {
+	var args struct {
+		Global bool `arg:"-g"`
+		Sub    *struct {
+			Guard bool `arg:"-g"`
+		} `arg:"subcommand"`
+	}
+
+	p, err := NewParser(Config{StrictSubcommands: true}, &args)
+	require.NoError(t, err)
+
+	err = p.Parse([]string{"sub", "-g"})
+	assert.NoError(t, err)
+	assert.False(t, args.Global)
+	assert.True(t, args.Sub.Guard)
+}

From 5036dce2d6a64b2dd1b6e270947bde1e8110708c Mon Sep 17 00:00:00 2001
From: Alexey Trofimov <dmzkrsk@gmail.com>
Date: Wed, 18 Jan 2023 11:52:13 +0300
Subject: [PATCH 2/2] fix typo

---
 parse.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/parse.go b/parse.go
index 3efe858..b935fad 100644
--- a/parse.go
+++ b/parse.go
@@ -116,7 +116,7 @@ type Config struct {
 	// default values, including pointers to sub commands
 	IgnoreDefault bool
 
-	// IgnoreDefault intructs the library not to allow global commands after
+	// StrictSubcommands intructs the library not to allow global commands after
 	// subcommand
 	StrictSubcommands bool
 }