Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

index/scorch/snapshot_index_test.go

@@ -0,0 +1,90 @@
+package scorch
+
+import (
+	"testing"
+
+	"github.com/blevesearch/vellum"
+)
+
+func TestIndexSnapshot_getLevAutomaton(t *testing.T) {
+	// Create a dummy IndexSnapshot (parent doesn't matter for this method)
+	is := &IndexSnapshot{}
+
+	tests := []struct {
+		name        string
+		term        string
+		fuzziness   uint8
+		expectError bool
+		errorMsg    string // Optional: check specific error message
+	}{
+		{
+			name:        "fuzziness 1",
+			term:        "test",
+			fuzziness:   1,
+			expectError: false,
+		},
+		{
+			name:        "fuzziness 2",
+			term:        "another",
+			fuzziness:   2,
+			expectError: false,
+		},
+		{
+			name:        "fuzziness 0",
+			term:        "zero",
+			fuzziness:   0,
+			expectError: true,
+			errorMsg:    "fuzziness exceeds the max limit",
+		},
+		{
+			name:        "fuzziness 3",
+			term:        "three",
+			fuzziness:   3,
+			expectError: true,
+			errorMsg:    "fuzziness exceeds the max limit",
+		},
+		{
+			name:        "empty term fuzziness 1",
+			term:        "",
+			fuzziness:   1,
+			expectError: false,
+		},
+		{
+			name:        "empty term fuzziness 2",
+			term:        "",
+			fuzziness:   2,
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotAutomaton, err := is.getLevAutomaton(tt.term, tt.fuzziness)
+
+			if tt.expectError {
+				if err == nil {
+					t.Errorf("getLevAutomaton() expected an error but got nil")
+				} else if tt.errorMsg != "" && err.Error() != tt.errorMsg {
+					t.Errorf("getLevAutomaton() expected error msg %q but got %q", tt.errorMsg, err.Error())
+				}
+				if gotAutomaton != nil {
+					t.Errorf("getLevAutomaton() expected nil automaton on error but got %v", gotAutomaton)
+				}
+			} else {
+				if err != nil {
+					t.Errorf("getLevAutomaton() got unexpected error: %v", err)
+				}
+				if gotAutomaton == nil {
+					t.Errorf("getLevAutomaton() expected a valid automaton but got nil")
+				}
+				// Optional: Check type if needed, though non-nil is usually sufficient
+				_, ok := gotAutomaton.(vellum.Automaton)
+				if !ok {
+					t.Errorf("getLevAutomaton() returned type is not vellum.Automaton")
+				}
+			}
+		})
+	}
+}
+
+// Add other tests for snapshot_index.go below if needed...