fix: prevent nil pointer panic in profiling, unchecked JSON decode, and index out of bounds in lint

- Fix stopProfiling to only register defer f.Close() when os.Create
  succeeds, preventing nil pointer dereference when file creation fails
- Check error from json.NewDecoder().Decode() in SearchWithContext
  instead of silently discarding it
- Add bounds check for empty directory after tarball extraction in
  lintChart to prevent index out of range panic

Signed-off-by: Akanksha Trehun <akankshatrehun@gmail.com>

internal/monocular/search.go

@@ -142,7 +142,9 @@ func (c *Client) SearchWithContext(ctx context.Context, term string) ([]SearchRe
 
 	result := &searchResponse{}
 
-	json.NewDecoder(res.Body).Decode(result)
+	if err := json.NewDecoder(res.Body).Decode(result); err != nil {
+		return nil, fmt.Errorf("failed to decode search results from %s: %w", p.String(), err)
+	}
 
 	return result.Data, nil
 }

pkg/action/lint.go

@@ -112,6 +112,9 @@ func lintChart(path string, vals map[string]any, namespace string, kubeVersion *
 		if err != nil {
 			return linter, fmt.Errorf("unable to read temporary output directory %s: %w", tempDir, err)
 		}
+		if len(files) == 0 {
+			return linter, fmt.Errorf("temporary output directory %s is empty after extraction", tempDir)
+		}
 		if !files[0].IsDir() {
 			return linter, fmt.Errorf("unexpected file %s in temporary output directory %s", files[0].Name(), tempDir)
 		}

pkg/cmd/profiling.go

@@ -74,12 +74,13 @@ func stopProfiling() error {
 		f, err := os.Create(memProfilePath)
 		if err != nil {
 			errs = append(errs, err)
-		}
-		defer f.Close()
+		} else {
+			defer f.Close()
 
-		runtime.GC() // get up-to-date statistics
-		if err := pprof.WriteHeapProfile(f); err != nil {
-			errs = append(errs, err)
+			runtime.GC() // get up-to-date statistics
+			if err := pprof.WriteHeapProfile(f); err != nil {
+				errs = append(errs, err)
+			}
 		}
 	}