Solidify editor mechanics

I've looked into what github does, so they use a mix of this approach, and
the survey approach.

To keep it simple, we're only gonna go with the manual approach they do until
we feel the full blown prompt approach is necessary.

Closes #189

internal/cli/rules.go

@@ -67,10 +67,10 @@ func rulesCmd(cli *cli) *cobra.Command {
 
 func listRulesCmd(cli *cli) *cobra.Command {
 	cmd := &cobra.Command{
-		Use:   "list",
+		Use:     "list",
 		Aliases: []string{"ls"},
-		Short: "List your rules",
-		Long:  `List the rules in your current tenant.`,
+		Short:   "List your rules",
+		Long:    `List the rules in your current tenant.`,
 		Example: `auth0 rules list
 auth0 rules ls`,
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -106,9 +106,9 @@ func createRuleCmd(cli *cli) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "create",
 		Short: "Create a new rule",
-		Long: `Create a new rule:`,
-		Example: `auth0 rules create 
-auth0 rules create --name "My Rule" 
+		Long:  `Create a new rule:`,
+		Example: `auth0 rules create
+auth0 rules create --name "My Rule"
 auth0 rules create -n "My Rule" --template "Empty rule"
 auth0 rules create -n "My Rule" -t "Empty rule" --enabled=false`,
 		PreRun: func(cmd *cobra.Command, args []string) {
@@ -129,6 +129,9 @@ auth0 rules create -n "My Rule" -t "Empty rule" --enabled=false`,
 			script, err := prompt.CaptureInputViaEditor(
 				ruleTemplateOptions.getValue(inputs.Template),
 				inputs.Name+".*.js",
+				func() {
+					cli.renderer.Infof("%s once you close the editor, the rule will be saved. To cancel, CTRL+C.", ansi.Faint("Hint:"))
+				},
 			)
 			if err != nil {
 				return fmt.Errorf("Failed to capture input from the editor: %w", err)
@@ -169,7 +172,7 @@ func showRuleCmd(cli *cli) *cobra.Command {
 		Use:   "show",
 		Args:  cobra.MaximumNArgs(1),
 		Short: "Show a rule",
-		Long: `Show a rule:`,
+		Long:  `Show a rule:`,
 		Example: `auth0 rules show 
 auth0 rules show <id>`,
 		PreRun: func(cmd *cobra.Command, args []string) {
@@ -213,7 +216,7 @@ func deleteRuleCmd(cli *cli) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "delete",
 		Short: "Delete a rule",
-		Long: `Delete a rule`,
+		Long:  `Delete a rule`,
 		Example: `auth0 rules delete 
 auth0 rules delete <rule-id>`,
 		PreRun: func(cmd *cobra.Command, args []string) {
@@ -254,7 +257,7 @@ func updateRuleCmd(cli *cli) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "update",
 		Short: "Update a rule",
-		Long: `Update a rule`,
+		Long:  `Update a rule`,
 		Example: `auth0 rules update <rule-id> 
 auth0 rules update <rule-id> --name "My Updated Rule"
 auth0 rules update <rule-id> -n "My Updated Rule" --enabled=false`,
@@ -291,6 +294,9 @@ auth0 rules update <rule-id> -n "My Updated Rule" --enabled=false`,
 			script, err := prompt.CaptureInputViaEditor(
 				rule.GetScript(),
 				rule.GetName()+".*.js",
+				func() {
+					cli.renderer.Infof("%s once you close the editor, the rule will be saved. To cancel, CTRL+C.", ansi.Faint("Hint:"))
+				},
 			)
 			if err != nil {
 				return fmt.Errorf("Failed to capture input from the editor: %w", err)

internal/prompt/editor.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"runtime"
 
 	"github.com/kballard/go-shellquote"
 )
@@ -14,48 +15,58 @@ const (
 )
 
 var (
-	bom = []byte{0xef, 0xbb, 0xbf}
+	bom        = []byte{0xef, 0xbb, 0xbf}
+	cliEditors = []string{"vi", "vim", "nano"}
 )
 
-var defaultEditorPrompt = &editorPrompt{defaultEditor: defaultEditor}
+var defaultEditorPrompt = &editorPrompt{editorCmd: getDefaultEditor()}
 
 // CaptureInputViaEditor is the high level function to use in this package in
 // order to capture input from an editor.
 //
 // The arguments have been tailored for our use of strings mostly in the rest
 // of the CLI even though internally we're using []byte.
-func CaptureInputViaEditor(contents, pattern string) (result string, err error) {
-	v, err := defaultEditorPrompt.captureInput([]byte(contents), pattern)
+func CaptureInputViaEditor(contents, pattern string, infoFn func()) (result string, err error) {
+	v, err := defaultEditorPrompt.captureInput([]byte(contents), pattern, infoFn)
 	return string(v), err
 }
 
 type editorPrompt struct {
-	defaultEditor string
+	editorCmd string
 }
 
-// GetPreferredEditorFromEnvironment returns the user's editor as defined by the
-// `$EDITOR` environment variable, or the `defaultEditor` if it is not set.
-func (p *editorPrompt) getPreferredEditor() string {
-	editor := os.Getenv("EDITOR")
-
-	if editor == "" {
-		return p.defaultEditor
+// getDefaultEditor is taken from https://github.com/cli/cli/blob/trunk/pkg/surveyext/editor_manual.go
+// and tries to infer the editor from different heuristics.
+func getDefaultEditor() string {
+	if runtime.GOOS == "windows" {
+		return "notepad"
+	} else if g := os.Getenv("GIT_EDITOR"); g != "" {
+		return g
+	} else if v := os.Getenv("VISUAL"); v != "" {
+		return v
+	} else if e := os.Getenv("EDITOR"); e != "" {
+		return e
 	}
 
-	return editor
+	return defaultEditor
 }
 
 // openFile opens filename in the preferred text editor, resolving the
 // arguments with editor specific logic.
-func (p *editorPrompt) openFile(filename string) error {
-	editorCommand := p.getPreferredEditor()
-
-	args, err := shellquote.Split(editorCommand)
+func (p *editorPrompt) openFile(filename string, infoFn func()) error {
+	args, err := shellquote.Split(p.editorCmd)
 	if err != nil {
 		return err
 	}
 	args = append(args, filename)
 
+	isCLIEditor := false
+	for _, e := range cliEditors {
+		if e == args[0] {
+			isCLIEditor = true
+		}
+	}
+
 	editorExe, err := exec.LookPath(args[0])
 	if err != nil {
 		return err
@@ -66,6 +77,10 @@ func (p *editorPrompt) openFile(filename string) error {
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 
+	if !isCLIEditor && infoFn != nil {
+		infoFn()
+	}
+
 	return cmd.Run()
 }
 
@@ -75,7 +90,7 @@ func (p *editorPrompt) openFile(filename string) error {
 //
 // If given default contents, it will write that to the file before popping
 // open the editor.
-func (p *editorPrompt) captureInput(contents []byte, pattern string) ([]byte, error) {
+func (p *editorPrompt) captureInput(contents []byte, pattern string, infoFn func()) ([]byte, error) {
 	file, err := os.CreateTemp(os.TempDir(), pattern)
 	if err != nil {
 		return []byte{}, err
@@ -102,16 +117,11 @@ func (p *editorPrompt) captureInput(contents []byte, pattern string) ([]byte, er
 		}
 	}
 
-	// close the fd to allow the editor to save file
-	if err := file.Close(); err != nil {
-		return nil, err
-	}
-
 	if err = file.Close(); err != nil {
 		return nil, err
 	}
 
-	if err = p.openFile(filename); err != nil {
+	if err = p.openFile(filename, infoFn); err != nil {
 		return nil, err
 	}