Fix failing test

Signed-off-by: Evans Mungai <mbuevans@gmail.com>

pkg/chart/common/util/jsonschema.go

@@ -83,7 +83,7 @@ func ValidateAgainstSchema(ch chart.Charter, values map[string]interface{}) erro
 		slog.Debug("chart name", "chart-name", chrt.Name())
 		err := ValidateAgainstSingleSchema(values, chrt.Schema())
 		if err != nil {
-			sb.WriteString(fmt.Sprintf("%s:\n", chrt.Name()))
+			fmt.Fprintf(&sb, "%s:\n", chrt.Name())
 			sb.WriteString(err.Error())
 		}
 	}
@@ -103,10 +103,8 @@ func ValidateAgainstSchema(ch chart.Charter, values map[string]interface{}) erro
 
 		subchartValues, ok := raw.(map[string]any)
 		if !ok {
-			sb.WriteString(fmt.Sprintf(
-				"%s:\ninvalid type for values: expected object (map), got %T\n",
-				sub.Name(), raw,
-			))
+			fmt.Fprintf(&sb, "%s:\ninvalid type for values: expected object (map), got %T\n",
+				sub.Name(), raw)
 			continue
 		}
 

pkg/cmd/pull_test.go

@@ -22,6 +22,7 @@ import (
 	"net/http/httptest"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"helm.sh/helm/v4/pkg/repo/v1/repotest"
@@ -520,7 +521,7 @@ func TestPullOCIWithTagAndDigest(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	result := ociSrv.Run(t)
+	result := ociSrv.RunWithReturn(t)
 
 	contentCache := t.TempDir()
 	outdir := t.TempDir()
@@ -543,12 +544,15 @@ func TestPullOCIWithTagAndDigest(t *testing.T) {
 	}
 
 	// Verify the file was downloaded
-	// When digest is present, the filename uses the digest format
+	// When digest is present, the filename uses the digest format (e.g. chart@sha256-hex.tgz)
 	expectedFile := filepath.Join(outdir, "oci-dependent-chart-0.1.0.tgz")
 	if _, err := os.Stat(expectedFile); err != nil {
-		// Try the digest-based filename
-		digestPart := result.PushedChart.Manifest.Digest[7:] // strip "sha256:"
-		expectedFile = filepath.Join(outdir, fmt.Sprintf("oci-dependent-chart@sha256-%s.tgz", digestPart))
+		// Try the digest-based filename; parse algorithm:hex to avoid fixed-offset assumptions
+		algorithm, digestPart, ok := strings.Cut(result.PushedChart.Manifest.Digest, ":")
+		if !ok {
+			t.Fatalf("digest must be in algorithm:hex format, got %q", result.PushedChart.Manifest.Digest)
+		}
+		expectedFile = filepath.Join(outdir, fmt.Sprintf("oci-dependent-chart@%s-%s.tgz", algorithm, digestPart))
 		if _, err := os.Stat(expectedFile); err != nil {
 			t.Errorf("expected chart file not found: %v", err)
 		}

pkg/downloader/chart_downloader.go

@@ -130,6 +130,10 @@ func (c *ChartDownloader) DownloadTo(ref, version, dest string) (string, *proven
 		if err != nil {
 			return "", nil, err
 		}
+		if len(digest) != 32 {
+			return "", nil, fmt.Errorf("invalid digest length: %d", len(digest))
+		}
+
 		copy(digest32[:], digest)
 		if pth, err := c.Cache.Get(digest32, CacheChart); err == nil {
 			fdata, err := os.ReadFile(pth)
@@ -237,6 +241,9 @@ func (c *ChartDownloader) DownloadToCache(ref, version string) (string, *provena
 	if err != nil {
 		return "", nil, fmt.Errorf("unable to decode digest: %w", err)
 	}
+	if digestString != "" && len(digest) != 32 {
+		return "", nil, fmt.Errorf("invalid digest length: %d", len(digest))
+	}
 	var digest32 [32]byte
 	copy(digest32[:], digest)
 

pkg/repo/v1/repotest/server.go

@@ -213,7 +213,12 @@ func NewOCIServer(t *testing.T, dir string) (*OCIServer, error) {
 	}, nil
 }
 
-func (srv *OCIServer) Run(t *testing.T, opts ...OCIServerOpt) *OCIServerRunResult {
+func (srv *OCIServer) Run(t *testing.T, opts ...OCIServerOpt) {
+	t.Helper()
+	_ = srv.RunWithReturn(t, opts...)
+}
+
+func (srv *OCIServer) RunWithReturn(t *testing.T, opts ...OCIServerOpt) *OCIServerRunResult {
 	t.Helper()
 	cfg := &OCIServerRunConfig{}
 	for _, fn := range opts {