Separate engine loading from inspection state

internal/engine/independence_test.go

@@ -38,7 +38,7 @@ func TestParallelLoadsShareRulesButNotMutableValues(t *testing.T) {
 	}
 
 	const count = 32
-	results := make([]*Result[independentConfig], count)
+	results := make([]*testResult[independentConfig], count)
 	errorsByIndex := make([]error, count)
 	var group sync.WaitGroup
 	for index := range count {
@@ -73,6 +73,29 @@ func TestParallelLoadsShareRulesButNotMutableValues(t *testing.T) {
 	}
 }
 
+func TestLoadedConfigurationIsSeparateFromInspection(t *testing.T) {
+	type configuration struct {
+		Value string `yaml:"value"`
+	}
+
+	loaded, err := Load[configuration](Bytes("config.yml", []byte("value: original\n")), testSecretBinding())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if loaded.Inspection == nil {
+		t.Fatal("inspection is nil")
+	}
+
+	loaded.Config.Value = "mutated"
+	var effective bytes.Buffer
+	if err := loaded.Inspection.WriteEffective(&effective); err != nil {
+		t.Fatal(err)
+	}
+	if effective.String() != "value: original\n" {
+		t.Fatalf("inspection changed with configuration: %q", effective.String())
+	}
+}
+
 func TestConcurrentLoadsOfCopiedReaderSourceHaveOneClaim(t *testing.T) {
 	source := Reader("shared", strings.NewReader("value: one\n"))
 	copied := source