Cobra generator now works within Go modules

Pretty major change in behavior, but with modules a change is needed.
Now cobra can initialize and add from within any Go module.
The experience is simplified and streamlined, but requires `go mod init` to happen first.

cobra/cmd/init.go

@@ -1,4 +1,4 @@
-// Copyright © 2015 Steve Francia <spf@spf13.com>.
+// Copyright © 2021 Steve Francia <spf@spf13.com>.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -14,42 +14,41 @@
 package cmd
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
+	"os/exec"
 	"path"
+	"path/filepath"
+	"strings"
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 )
 
 var (
-	pkgName string
-
 	initCmd = &cobra.Command{
-		Use:     "init [name]",
+		Use:     "init [path]",
 		Aliases: []string{"initialize", "initialise", "create"},
 		Short:   "Initialize a Cobra Application",
 		Long: `Initialize (cobra init) will create a new application, with a license
 and the appropriate structure for a Cobra-based CLI application.
 
-  * If a name is provided, a directory with that name will be created in the current directory;
-  * If no name is provided, the current directory will be assumed;
+Cobra init must be run inside of a go module (please run "go mod init <MODNAME>" first)
 `,
 
 		Run: func(_ *cobra.Command, args []string) {
-
 			projectPath, err := initializeProject(args)
 			cobra.CheckErr(err)
+			cobra.CheckErr(goGet("github.com/spf13/cobra"))
+			if viper.GetBool("useViper") {
+				cobra.CheckErr(goGet("github.com/spf13/viper"))
+			}
 			fmt.Printf("Your Cobra application is ready at\n%s\n", projectPath)
 		},
 	}
 )
 
-func init() {
-	initCmd.Flags().StringVar(&pkgName, "pkg-name", "", "fully qualified pkg name")
-	cobra.CheckErr(initCmd.MarkFlagRequired("pkg-name"))
-}
-
 func initializeProject(args []string) (string, error) {
 	wd, err := os.Getwd()
 	if err != nil {
@@ -62,13 +61,15 @@ func initializeProject(args []string) (string, error) {
 		}
 	}
 
+	modName := getModImportPath()
+
 	project := &Project{
 		AbsolutePath: wd,
-		PkgName:      pkgName,
+		PkgName:      modName,
 		Legal:        getLicense(),
 		Copyright:    copyrightLine(),
 		Viper:        viper.GetBool("useViper"),
-		AppName:      path.Base(pkgName),
+		AppName:      path.Base(modName),
 	}
 
 	if err := project.Create(); err != nil {
@@ -77,3 +78,52 @@ func initializeProject(args []string) (string, error) {
 
 	return project.AbsolutePath, nil
 }
+
+func getModImportPath() string {
+	mod, cd := parseModInfo()
+	return path.Join(mod.Path, fileToURL(strings.TrimPrefix(cd.Dir, mod.Dir)))
+}
+
+func fileToURL(in string) string {
+	i := strings.Split(in, string(filepath.Separator))
+	return path.Join(i...)
+}
+
+func parseModInfo() (Mod, CurDir) {
+	var mod Mod
+	var dir CurDir
+
+	m := modInfoJSON("-m")
+	cobra.CheckErr(json.Unmarshal(m, &mod))
+
+	// Unsure why, but if no module is present Path is set to this string.
+	if mod.Path == "command-line-arguments" {
+		cobra.CheckErr("Please run `go mod init <MODNAME>` before `cobra init`")
+	}
+
+	e := modInfoJSON("-e")
+	cobra.CheckErr(json.Unmarshal(e, &dir))
+
+	return mod, dir
+}
+
+type Mod struct {
+	Path, Dir, GoMod string
+}
+
+type CurDir struct {
+	Dir string
+}
+
+func goGet(mod string) error {
+	cmd := exec.Command("go", "get", mod)
+	return cmd.Run()
+}
+
+func modInfoJSON(args ...string) []byte {
+	cmdArgs := append([]string{"list", "-json"}, args...)
+	out, err := exec.Command("go", cmdArgs...).Output()
+	cobra.CheckErr(err)
+
+	return out
+}

cobra/cmd/init_test.go

@@ -16,8 +16,8 @@ func getProject() *Project {
 		AbsolutePath: fmt.Sprintf("%s/testproject", wd),
 		Legal:        getLicense(),
 		Copyright:    copyrightLine(),
-		AppName:      "testproject",
-		PkgName:      "github.com/spf13/testproject",
+		AppName:      "cmd",
+		PkgName:      "github.com/spf13/cobra/cobra/cmd/cmd",
 		Viper:        true,
 	}
 }
@@ -37,29 +37,16 @@ func TestGoldenInitCmd(t *testing.T) {
 		expectErr bool
 	}{
 		{
-			name:      "successfully creates a project with name",
+			name:      "successfully creates a project based on module",
 			args:      []string{"testproject"},
 			pkgName:   "github.com/spf13/testproject",
 			expectErr: false,
 		},
-		{
-			name:      "returns error when passing an absolute path for project",
-			args:      []string{dir},
-			pkgName:   "github.com/spf13/testproject",
-			expectErr: true,
-		},
-		{
-			name:      "returns error when passing a relative path for project",
-			args:      []string{"github.com/spf13/testproject"},
-			pkgName:   "github.com/spf13/testproject",
-			expectErr: true,
-		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 
-			assertNoErr(t, initCmd.Flags().Set("pkg-name", tt.pkgName))
 			viper.Set("useViper", true)
 			viper.Set("license", "apache")
 			projectPath, err := initializeProject(tt.args)

cobra/cmd/testdata/main.go.golden

@@ -15,7 +15,7 @@ limitations under the License.
 */
 package main
 
-import "github.com/spf13/testproject/cmd"
+import "github.com/spf13/cobra/cobra/cmd/cmd"
 
 func main() {
 	cmd.Execute()

cobra/cmd/testdata/root.go.golden

@@ -18,16 +18,16 @@ package cmd
 import (
 	"fmt"
 	"os"
-	"github.com/spf13/cobra"
 
+	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 )
 
 var cfgFile string
 
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
-	Use:   "testproject",
+	Use:   "cmd",
 	Short: "A brief description of your application",
 	Long: `A longer description that spans multiple lines and likely contains
 examples and usage of using your application. For example:
@@ -53,7 +53,7 @@ func init() {
 	// Cobra supports persistent flags, which, if defined here,
 	// will be global for your application.
 
-	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.testproject.yaml)")
+	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.cmd.yaml)")
 
 	// Cobra also supports local flags, which will only run
 	// when this action is called directly.
@@ -70,10 +70,10 @@ func initConfig() {
 		home, err := os.UserHomeDir()
 		cobra.CheckErr(err)
 
-		// Search config in home directory with name ".testproject" (without extension).
+		// Search config in home directory with name ".cmd" (without extension).
 		viper.AddConfigPath(home)
 		viper.SetConfigType("yaml")
-		viper.SetConfigName(".testproject")
+		viper.SetConfigName(".cmd")
 	}
 
 	viper.AutomaticEnv() // read in environment variables that match