fix: downgrade issue

Signed-off-by: Akash Kumar <[email protected]>

pkg/mvs/mvs.go

@@ -7,7 +7,7 @@ import (
 	"github.com/hashicorp/go-version"
 	"golang.org/x/mod/module"
 	"kcl-lang.io/kpm/pkg/client"
-	"kcl-lang.io/kpm/pkg/errors"
+	errInt "kcl-lang.io/kpm/pkg/errors"
 	"kcl-lang.io/kpm/pkg/git"
 	"kcl-lang.io/kpm/pkg/oci"
 	pkg "kcl-lang.io/kpm/pkg/package"
@@ -98,11 +98,18 @@ func (r ReqsGraph) Previous(m module.Version) (module.Version, error) {
 		return m, nil
 	}
 
+	// copy the version to compare it later
+	v := m.Version
+
 	m.Version, err = semver.LeastOldCompatibleVersion(releases, m.Version)
-	if err != nil {
+	if err != nil && err != errInt.InvalidVersionFormat {
 		return module.Version{}, err
 	}
 
+	if v == m.Version {
+		return module.Version{Path: m.Path, Version: "none"}, nil
+	}
+
 	_, err = r.Vertex(m)
 	if err == graph.ErrVertexNotFound {
 		d := pkg.Dependency{
@@ -147,7 +154,7 @@ func getReleasesFromSource(properties graph.VertexProperties) ([]string, error)
 
 	// there must be only one property depending on the download source type
 	if len(properties.Attributes) != 1 {
-		return nil, errors.MultipleSources
+		return nil, errInt.MultipleSources
 	}
 
 	for k, v := range properties.Attributes {

pkg/mvs/mvs_test.go

@@ -222,12 +222,11 @@ func TestDowngrade(t *testing.T) {
 	assert.Equal(t, err, nil)
 
 	expectedReqs := []module.Version{
-		{Path: "test_with_external_deps", Version: "0.0.1"},
-		{Path: "argo-cd-order", Version: "0.2.0"},
-		{Path: "helloworld", Version: "0.1.1"},
-		{Path: "json_merge_patch", Version: "0.1.0"},
-		{Path: "k8s", Version: "1.27"},
-		{Path: "podinfo", Version: "0.1.1"},
+		{Path:"test_with_external_deps", Version:"0.0.1"},
+		{Path:"argo-cd-order", Version:"0.1.2"},
+		{Path:"helloworld", Version:"0.1.0"},
+		{Path:"json_merge_patch", Version:"0.1.0"},
+		{Path:"k8s", Version:"1.17"},
 	}
 	assert.Equal(t, downgrade, expectedReqs)
 }

pkg/semver/semver.go

@@ -27,33 +27,23 @@ func LatestVersion(versions []string) (string, error) {
 	return latest.Original(), nil
 }
 
-// LeastOldVersion returns the version that is most recent and less than the base version.
-func LeastOldVersion(versions []string, baseVersion string) (string, error) {
-	base, err := version.NewVersion(baseVersion)
-	if err != nil {
-		return "", fmt.Errorf("invalid base version: %v", err)
-	}
-
-	var leastOld *version.Version
+func OldestVersion(versions []string) (string, error) {
+	var oldest *version.Version
 	for _, v := range versions {
 		ver, err := version.NewVersion(v)
 		if err != nil {
 			return "", reporter.NewErrorEvent(reporter.FailedParseVersion, err, fmt.Sprintf("failed to parse version %s", v))
 		}
-
-		// Only consider versions less than the base version
-		if ver.LessThan(base) {
-			if leastOld == nil || ver.GreaterThan(leastOld) {
-				leastOld = ver
-			}
+		if oldest == nil || ver.LessThan(oldest) {
+			oldest = ver
 		}
 	}
 
-	if leastOld == nil {
+	if oldest == nil {
 		return "", errors.InvalidVersionFormat
 	}
 
-	return leastOld.Original(), nil
+	return oldest.Original(), nil
 }
 
 func filterCompatibleVersions(versions []string, baseVersion string) ([]string, error) {
@@ -87,5 +77,5 @@ func LeastOldCompatibleVersion(versions []string, baseVersion string) (string, e
 	if err != nil {
 		return "", err
 	}
-	return LeastOldVersion(compatibleVersions, baseVersion)
+	return OldestVersion(compatibleVersions)
 }

pkg/semver/semver_test.go

@@ -39,14 +39,14 @@ func TestTheLatestTagWithMissingVersion(t *testing.T) {
 	assert.Equal(t, latest, "5.5")
 }
 
-func TestLeastOldVersion(t *testing.T) {
-	leastOld, err := LeastOldVersion([]string{"1.2.3", "1.4.0", "2.0.0", "1.3.5", "1.0.0"}, "1.2.0")
+func TestOldestVersion(t *testing.T) {
+	oldest, err := OldestVersion([]string{"1.2.3", "1.4.0", "2.0.0", "1.3.5", "1.0.0"})
 	assert.Equal(t, err, nil)
-	assert.Equal(t, leastOld, "1.0.0")
+	assert.Equal(t, oldest, "1.0.0")
 
-	leastOld, err = LeastOldVersion([]string{"2.2.0", "2.4.0", "3.0.0", "2.3.5"}, "2.5.0")
+	oldest, err = OldestVersion([]string{"2.2.0", "2.4.0", "3.0.0", "2.3.5"})
 	assert.Equal(t, err, nil)
-	assert.Equal(t, leastOld, "2.4.0")
+	assert.Equal(t, oldest, "2.2.0")
 }
 
 func TestFilterCompatibleVersions(t *testing.T) {