Implemented confi snapshots

internal/confmgr/store_test.go

@@ -41,6 +41,76 @@ func TestCreateAndGetSet(t *testing.T) {
 	}
 }
 
+func TestRuleBlocksInvalidInstance(t *testing.T) {
+	s, _ := New(t.TempDir())
+	set, _ := s.CreateSet(sampleSet(), "")
+	if _, err := s.CreateRule(ConfigRule{
+		Name:   "voltage cap",
+		SetID:  set.ID,
+		Source: "voltage: <=24",
+	}, ""); err != nil {
+		t.Fatal(err)
+	}
+
+	// In-range value passes.
+	if _, err := s.CreateInstance(ConfigInstance{
+		Name: "ok", SetID: set.ID, Values: map[string]any{"voltage": 20.0},
+	}, ""); err != nil {
+		t.Fatalf("expected in-range instance to save, got %v", err)
+	}
+
+	// Out-of-range value is rejected by the rule.
+	_, err := s.CreateInstance(ConfigInstance{
+		Name: "bad", SetID: set.ID, Values: map[string]any{"voltage": 40.0},
+	}, "")
+	if err == nil {
+		t.Fatalf("expected rule violation to block save")
+	}
+	var re *RuleError
+	if !asRuleError(err, &re) {
+		t.Fatalf("expected *RuleError, got %T: %v", err, err)
+	}
+}
+
+func TestRuleTransformPersists(t *testing.T) {
+	s, _ := New(t.TempDir())
+	set := sampleSet()
+	max := 48.0
+	set.Parameters = append(set.Parameters, Parameter{Key: "vmax", DS: "epics", Signal: "PSU:VMAX", Type: TypeFloat, Min: &max})
+	created, _ := s.CreateSet(set, "")
+	// Rule derives vmax = voltage * 2 (within range for voltage=20 -> 40).
+	if _, err := s.CreateRule(ConfigRule{
+		Name: "vmax derive", SetID: created.ID, Source: "voltage: number\nvmax: voltage * 2",
+	}, ""); err != nil {
+		t.Fatal(err)
+	}
+	inst, err := s.CreateInstance(ConfigInstance{
+		Name: "x", SetID: created.ID, Values: map[string]any{"voltage": 20.0},
+	}, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if f, _ := toFloat(inst.Values["vmax"]); f != 40 {
+		t.Fatalf("expected derived vmax=40 to persist, got %v", inst.Values["vmax"])
+	}
+}
+
+func asRuleError(err error, target **RuleError) bool {
+	for err != nil {
+		if re, ok := err.(*RuleError); ok {
+			*target = re
+			return true
+		}
+		type unwrapper interface{ Unwrap() error }
+		u, ok := err.(unwrapper)
+		if !ok {
+			return false
+		}
+		err = u.Unwrap()
+	}
+	return false
+}
+
 func TestSetVersioning(t *testing.T) {
 	s, _ := New(t.TempDir())
 	created, _ := s.CreateSet(sampleSet(), "")