refactor: use source directory name for default root command name

examples/posargs/clap.gen.go

@@ -117,10 +117,10 @@ func numError(err error) error {
 }
 
 func (*mycli) UsageHelp() string {
-	return `mycli - Print a few positional args
+	return `posargs - Print a few positional args
 
 usage:
-   mycli [options] <f32> <text> <u16>
+   posargs [options] <f32> <text> <u16>
 
 options:
    -h   Show this help message
@@ -142,6 +142,6 @@ func (c *mycli) Parse(args []string) {
 	}
 	_, err := p.parse(args)
 	if err != nil {
-		clapFatalf("mycli", err.Error())
+		clapFatalf("posargs", err.Error())
 	}
 }

examples/simple/clap.gen.go

@@ -94,10 +94,10 @@ func (v *clapString) Set(s string) error {
 }
 
 func (*mycli) UsageHelp() string {
-	return `mycli - Print a string with the option to make it uppercase
+	return `simple - Print a string with the option to make it uppercase
 
 usage:
-   mycli [options] <input>
+   simple [options] <input>
 
 options:
    -upper   Make the input string all uppercase
@@ -119,6 +119,6 @@ func (c *mycli) Parse(args []string) {
 	}
 	_, err := p.parse(args)
 	if err != nil {
-		clapFatalf("mycli", err.Error())
+		clapFatalf("simple", err.Error())
 	}
 }

examples/simple_env/clap.gen.go

@@ -124,10 +124,10 @@ func numError(err error) error {
 }
 
 func (*mycli) UsageHelp() string {
-	return `mycli - Print a string with a prefix
+	return `simple_env - Print a string with a prefix
 
 usage:
-   mycli [options] [input]
+   simple_env [options] [input]
 
 options:
    -prefix  <arg>   The value to prepend to the input string [$MY_PREFIX]
@@ -151,6 +151,6 @@ func (c *mycli) Parse(args []string) {
 	}
 	_, err := p.parse(args)
 	if err != nil {
-		clapFatalf("mycli", err.Error())
+		clapFatalf("simple_env", err.Error())
 	}
 }

parse.go

@@ -6,6 +6,7 @@ import (
 	"go/ast"
 	"go/parser"
 	"go/token"
+	"path/filepath"
 	"regexp"
 	"strings"
 )
@@ -33,6 +34,12 @@ func parse(srcDir, rootCmdTypeName string) (command, string, error) {
 		srcDir = "."
 	}
 
+	absSrcDir, err := filepath.Abs(srcDir)
+	if err != nil {
+		return command{}, "", fmt.Errorf("getting absolute source directory path: %w", err)
+	}
+	rootCmdName := filepath.Base(absSrcDir)
+
 	fset := token.NewFileSet() // positions are relative to fset
 	parsedPkgs, err := parser.ParseDir(fset, srcDir, nil, parser.ParseComments)
 	if err != nil {
@@ -59,7 +66,7 @@ func parse(srcDir, rootCmdTypeName string) (command, string, error) {
 	root := command{
 		IsRoot:    true,
 		TypeName:  rootCmdTypeName,
-		FieldName: rootCmdTypeName,
+		FieldName: rootCmdName,
 		Data:      data,
 	}