when no changes are found, auto will return an error

* this applies to batch auto and next auto

README.md

@@ -24,6 +24,7 @@
 ## Getting Started
 * User documentation is available on the [website](https://changie.dev/).
 * Specifically, the [guide](https://changie.dev/guide/) is a good place to start.
+* There is also a [Changie GitHub Action](https://github.com/miniscruff/changie-action) you can use
 * View Changie's [Changelog](CHANGELOG.md) for an example.
 
 ## Need help?

core/utils.go

@@ -13,8 +13,9 @@ import (
 )
 
 var (
-	ErrBadVersionOrPart = errors.New("part string is not a supported version or version increment")
-	ErrMissingAutoLevel = errors.New("kind config missing auto level value for auto bumping")
+	ErrBadVersionOrPart      = errors.New("part string is not a supported version or version increment")
+	ErrMissingAutoLevel      = errors.New("kind config missing auto level value for auto bumping")
+	ErrNoChangesFoundForAuto = errors.New("no unreleased changes found for automatic bumping")
 )
 
 func AppendFile(opener shared.OpenFiler, rootFile io.Writer, path string) error {
@@ -93,6 +94,10 @@ func ValidBumpLevel(level string) bool {
 }
 
 func HighestAutoLevel(config Config, allChanges []Change) (string, error) {
+	if len(allChanges) == 0 {
+		return "", ErrNoChangesFoundForAuto
+	}
+
 	highestLevel := PatchLevel
 
 	for _, change := range allChanges {

core/utils_test.go

@@ -575,6 +575,19 @@ func TestErrorHighestAutoLevelMissingKindConfig(t *testing.T) {
 	then.Err(t, ErrMissingAutoLevel, err)
 }
 
+func TestErrorHighestAutoLevelWithNoChanges(t *testing.T) {
+	cfg := Config{
+		Kinds: []KindConfig{
+			{
+				Label: "missing",
+			},
+		},
+	}
+	changes := []Change{}
+	_, err := HighestAutoLevel(cfg, changes)
+	then.Err(t, ErrNoChangesFoundForAuto, err)
+}
+
 func TestGetAllChanges(t *testing.T) {
 	cfg := utilsTestConfig()
 	_, afs := then.WithAferoFSConfig(t, cfg)