add prompt feature: select the patch/minor/major from prompt

README.adoc

@@ -4,12 +4,13 @@
 
 == USAGE
 
-    Usage: gobump (major|minor|patch|set <version>) [-w] [-v] [<path>]
+    Usage: gobump (major|minor|patch|up|set <version>|show) [-w] [-v] [<path>]
 
     Commands:
       major             bump major version up
       minor             bump minor version up
       patch             bump patch version up
+      up                bump up with prompt
       set <version>     set exact version (no increments)
       show              only show the versions (implies -v)
 

cli.go

@@ -18,12 +18,13 @@ func Run(argv []string, outStream, errStream io.Writer) error {
 	fs.Usage = func() {
 		out := errStream
 		fs.SetOutput(out)
-		fmt.Fprintln(out, `Usage: gobump (major|minor|patch|set <version>) [-w] [-v] [<path>]
+		fmt.Fprintln(out, `Usage: gobump (major|minor|patch|up|set <version>|show) [-w] [-v] [<path>]
 
 Commands:
   major             bump major version up
   minor             bump minor version up
   patch             bump patch version up
+  up                bump up with prompt
   set <version>     set exact version (no increments)
   show              only show the versions (implies -v)
 Flags:`)
@@ -42,6 +43,8 @@ Flags:`)
 		gb.Config.MinorDelta = 1
 	case "patch":
 		gb.Config.PatchDelta = 1
+	case "up":
+		gb.Config.Prompt = true
 	case "set":
 		if len(argv) < 2 {
 			return fmt.Errorf("please specify a version to set")

gobump.go

@@ -3,6 +3,7 @@ package gobump
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -113,6 +114,8 @@ type Config struct {
 	Exact string
 	// The pattern of "version" variable/constants. Defaults to /^(?i)version$/.
 	NamePattern *regexp.Regexp
+	// Prompt the bump up target (major, minor or patch)
+	Prompt bool
 	// Default version in the case none was set. Defaults to "0.0.0".
 	Default string
 }
@@ -216,6 +219,28 @@ func (conf Config) ProcessNode(fset *token.FileSet, node ast.Node) (versions map
 					currentVersion = v
 				}
 
+				if conf.Prompt {
+					result, err := promptTarget(currentVersion, fset.File(n.Pos()).Name())
+					if err != nil {
+						nodeErr = err
+						return false
+					}
+					conf.PatchDelta = 0
+					conf.MinorDelta = 0
+					conf.MajorDelta = 0
+					switch result {
+					case promptResultPatch:
+						conf.PatchDelta = 1
+					case promptResultMinor:
+						conf.MinorDelta = 1
+					case promptResultMajor:
+						conf.MajorDelta = 1
+					default:
+						nodeErr = errors.New("unexpected target")
+						return false
+					}
+				}
+
 				ver, err := conf.bumpedVersion(currentVersion)
 				if err != nil {
 					nodeErr = NodeErr{

prompt.go

@@ -0,0 +1,63 @@
+package gobump
+
+import (
+	"fmt"
+
+	"github.com/manifoldco/promptui"
+	"github.com/mattn/go-tty"
+)
+
+type promptResult int
+
+const (
+	promptResultNone promptResult = iota
+	promptResultPatch
+	promptResultMinor
+	promptResultMajor
+)
+
+func promptTarget(currentVersion, target string) (promptResult, error) {
+	tty, err := tty.Open()
+	if err != nil {
+		return promptResultNone, err
+	}
+	defer tty.Close()
+
+	candidates := []struct {
+		name   string
+		config Config
+		result promptResult
+	}{
+		{"patch", Config{PatchDelta: 1}, promptResultPatch},
+		{"minor", Config{MinorDelta: 1}, promptResultMinor},
+		{"major", Config{MajorDelta: 1}, promptResultMajor},
+	}
+
+	items := make([]string, len(candidates))
+	promptResults := make(map[int]promptResult)
+
+	for i, c := range candidates {
+		newVersion, err := c.config.bumpedVersion(currentVersion)
+		if err != nil {
+			return promptResultNone, err
+		}
+		items[i] = fmt.Sprintf("%s (%s -> %s)", c.name, currentVersion, newVersion)
+		promptResults[i] = c.result
+	}
+
+	prompt := promptui.Select{
+		Label:    "Bump up " + target,
+		HideHelp: true,
+		Items:    items,
+		Stdin:    tty.Input(),
+		Stdout:   tty.Output(),
+	}
+
+	index, _, err := prompt.Run()
+
+	if err != nil {
+		return promptResultNone, err
+	}
+
+	return promptResults[index], nil
+}