Fix command name collision on generator

When creating new commands via `cobra add`, it is not possible to add
commands with the same name to different parents. They will just
overwrite each other.

With this patch, the command's object identifier is templated
`parentCommandCmd`, the `Use` field `command` and the file name
`parent_command.go`.

Fixes #1059
Fixes #1131

Signed-off-by: Carlos Marx <me@carlosmarx.com>

cobra/cmd/add.go

@@ -46,10 +46,14 @@ Example: cobra add server -> resulting in a new cmd/server.go`,
 			wd, err := os.Getwd()
 			cobra.CheckErr(err)
 
-			commandName := validateCmdName(args[0])
+			commandUse := validateCmdName(args[0])
+			commandName, commandFileName := generateCmdFileName(commandUse, parentName)
+
 			command := &Command{
-				CmdName:   commandName,
+				CmdName:     commandName,
-				CmdParent: parentName,
+				CmdUse:      commandUse,
+				CmdFileName: commandFileName,
+				CmdParent:   parentName,
 				Project: &Project{
 					AbsolutePath: wd,
 					Legal:        getLicense(),
@@ -122,3 +126,39 @@ func validateCmdName(source string) string {
 	}
 	return output
 }
+
+// generateCmdFileName returns a lowerCamelCase command name and a snake_case
+// file name, combining the given command name and the parent command name.
+func generateCmdFileName(cmd, parent string) (string, string) {
+	var cmdName string
+	var cmdFileName string
+
+	if parent == "rootCmd" {
+		return cmd, cmd
+	}
+
+	l := len(parent)
+	if parent[l-3:] == "Cmd" {
+		parent = parent[:l-3]
+	}
+
+	upperCmd := string(unicode.ToUpper(rune(cmd[0]))) + cmd[1:]
+	lowerParent := string(unicode.ToLower(rune(parent[0]))) + parent[1:]
+	cmdName = lowerParent + upperCmd
+
+	l = len(cmdName)
+	cmdFileName = string(cmdName[0])
+	for i := 1; i < l; i++ {
+		if unicode.IsUpper(rune(cmdName[i])) {
+			cmdFileName += "_"
+		}
+		cmdFileName += string(unicode.ToLower(rune(cmdName[i])))
+	}
+
+	l = len(cmdFileName)
+	if cmdFileName[l-5:] == "_test" {
+		cmdFileName += "cmd"
+	}
+
+	return cmdName, cmdFileName
+}

cobra/cmd/add_test.go

@@ -8,9 +8,11 @@ import (
 
 func TestGoldenAddCmd(t *testing.T) {
 	command := &Command{
-		CmdName:   "test",
+		CmdName:     "test",
-		CmdParent: parentName,
+		CmdUse:      "test",
-		Project:   getProject(),
+		CmdFileName: "test",
+		CmdParent:   parentName,
+		Project:     getProject(),
 	}
 	defer os.RemoveAll(command.AbsolutePath)
 
@@ -48,3 +50,30 @@ func TestValidateCmdName(t *testing.T) {
 		}
 	}
 }
+
+func TestGenerateCmdFileName(t *testing.T) {
+	testCases := []struct {
+		inputCmd     string
+		inputParent  string
+		expectedCmd  string
+		expectedFile string
+	}{
+		{"cmdname", "parent", "parentCmdname", "parent_cmdname"},
+		{"cmdname", "parentCmd", "parentCmdname", "parent_cmdname"},
+		{"CmdName", "ParentCmd", "parentCmdName", "parent_cmd_name"},
+		{"cmdname", "granpaParentCmd", "granpaParentCmdname", "granpa_parent_cmdname"},
+		{"test", "granpaParentCmd", "granpaParentTest", "granpa_parent_testcmd"},
+		{"cmdname", "rootCmd", "cmdname", "cmdname"},
+	}
+
+	for _, testCase := range testCases {
+		got1, got2 := generateCmdFileName(testCase.inputCmd, testCase.inputParent)
+		if testCase.expectedCmd != got1 || testCase.expectedFile != got2 {
+			t.Errorf(
+				"Expected %q and %q, got %q and %q",
+				testCase.expectedCmd, testCase.expectedFile,
+				got1, got2,
+			)
+		}
+	}
+}

cobra/cmd/project.go

@@ -21,8 +21,10 @@ type Project struct {
 }
 
 type Command struct {
-	CmdName   string
+	CmdName     string
-	CmdParent string
+	CmdUse      string
+	CmdFileName string
+	CmdParent   string
 	*Project
 }
 
@@ -83,7 +85,7 @@ func (p *Project) createLicenseFile() error {
 }
 
 func (c *Command) Create() error {
-	cmdFile, err := os.Create(fmt.Sprintf("%s/cmd/%s.go", c.AbsolutePath, c.CmdName))
+	cmdFile, err := os.Create(fmt.Sprintf("%s/cmd/%s.go", c.AbsolutePath, c.CmdFileName))
 	if err != nil {
 		return err
 	}

cobra/tpl/main.go

@@ -113,9 +113,9 @@ import (
 	"github.com/spf13/cobra"
 )
 
-// {{ .CmdName }}Cmd represents the {{ .CmdName }} command
+// {{ .CmdName }}Cmd represents the {{ .CmdUse }} command
 var {{ .CmdName }}Cmd = &cobra.Command{
-	Use:   "{{ .CmdName }}",
+	Use:   "{{ .CmdUse }}",
 	Short: "A brief description of your command",
 	Long: ` + "`" + `A longer description that spans multiple lines and likely contains examples
 and usage of using your command. For example:
@@ -124,7 +124,7 @@ Cobra is a CLI library for Go that empowers applications.
 This application is a tool to generate the needed files
 to quickly create a Cobra application.` + "`" + `,
 	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Println("{{ .CmdName }} called")
+		fmt.Println("{{ .CmdUse }} called")
 	},
 }