better expression handling in lsp

internal/builder/builder.go

@@ -255,24 +255,7 @@ func (b *Builder) compute(left parser.Value, op parser.Token, right parser.Value
 		return &parser.StringValue{Value: s1 + s2, Quoted: true}
 	}
 
-	lF, lIsF := b.valToFloat(left)
+	// Try Integer arithmetic first
-	rF, rIsF := b.valToFloat(right)
-
-	if lIsF || rIsF {
-		res := 0.0
-		switch op.Type {
-		case parser.TokenPlus:
-			res = lF + rF
-		case parser.TokenMinus:
-			res = lF - rF
-		case parser.TokenStar:
-			res = lF * rF
-		case parser.TokenSlash:
-			res = lF / rF
-		}
-		return &parser.FloatValue{Value: res, Raw: fmt.Sprintf("%g", res)}
-	}
-
 	lI, lIsI := b.valToInt(left)
 	rI, rIsI := b.valToInt(right)
 
@@ -303,6 +286,25 @@ func (b *Builder) compute(left parser.Value, op parser.Token, right parser.Value
 		return &parser.IntValue{Value: res, Raw: fmt.Sprintf("%d", res)}
 	}
 
+	// Fallback to Float arithmetic
+	lF, lIsF := b.valToFloat(left)
+	rF, rIsF := b.valToFloat(right)
+
+	if lIsF || rIsF {
+		res := 0.0
+		switch op.Type {
+		case parser.TokenPlus:
+			res = lF + rF
+		case parser.TokenMinus:
+			res = lF - rF
+		case parser.TokenStar:
+			res = lF * rF
+		case parser.TokenSlash:
+			res = lF / rF
+		}
+		return &parser.FloatValue{Value: res, Raw: fmt.Sprintf("%g", res)}
+	}
+
 	return left
 }
 

internal/lsp/server.go

@@ -576,6 +576,8 @@ func HandleHover(params HoverParams) *Hover {
 		return nil
 	}
 
+	container := Tree.GetNodeContaining(path, parser.Position{Line: line, Column: col})
+
 	var content string
 
 	if res.Node != nil {
@@ -589,7 +591,7 @@ func HandleHover(params HoverParams) *Hover {
 	} else if res.Variable != nil {
 		content = fmt.Sprintf("**Variable**: `%s`\nType: `%s`", res.Variable.Name, res.Variable.TypeExpr)
 		if res.Variable.DefaultValue != nil {
-			content += fmt.Sprintf("\nDefault: `%s`", valueToString(res.Variable.DefaultValue))
+			content += fmt.Sprintf("\nDefault: `%s`", valueToString(res.Variable.DefaultValue, container))
 		}
 	} else if res.Reference != nil {
 		targetName := "Unresolved"
@@ -605,7 +607,7 @@ func HandleHover(params HoverParams) *Hover {
 			targetName = v.Name
 			fullInfo = fmt.Sprintf("**Variable**: `@%s`\nType: `%s`", v.Name, v.TypeExpr)
 			if v.DefaultValue != nil {
-				fullInfo += fmt.Sprintf("\nDefault: `%s`", valueToString(v.DefaultValue))
+				fullInfo += fmt.Sprintf("\nDefault: `%s`", valueToString(v.DefaultValue, container))
 			}
 		}
 
@@ -629,7 +631,8 @@ func HandleHover(params HoverParams) *Hover {
 	}
 }
 
-func valueToString(val parser.Value) string {
+func valueToString(val parser.Value, ctx *index.ProjectNode) string {
+	val = evaluate(val, ctx)
 	switch v := val.(type) {
 	case *parser.StringValue:
 		if v.Quoted {
@@ -649,7 +652,7 @@ func valueToString(val parser.Value) string {
 	case *parser.ArrayValue:
 		elements := []string{}
 		for _, e := range v.Elements {
-			elements = append(elements, valueToString(e))
+			elements = append(elements, valueToString(e, ctx))
 		}
 		return fmt.Sprintf("{ %s }", strings.Join(elements, " "))
 	default:
@@ -676,7 +679,7 @@ func HandleCompletion(params CompletionParams) *CompletionList {
 	prefix := lineStr[:col]
 
 	// Case 3: Variable completion
-	varRegex := regexp.MustCompile(`([@$])([a-zA-Z0-9_]*)$`)
+	varRegex := regexp.MustCompile(`([@])([a-zA-Z0-9_]*)$`)
 	if matches := varRegex.FindStringSubmatch(prefix); matches != nil {
 		container := Tree.GetNodeContaining(path, parser.Position{Line: params.Position.Line + 1, Column: col + 1})
 		if container == nil {
@@ -1292,6 +1295,55 @@ func formatNodeInfo(node *index.ProjectNode) string {
 		info += fmt.Sprintf("\n\n%s", node.Doc)
 	}
 
+	// Check if Implicit Signal peers exist
+	if ds, _ := getSignalInfo(node); ds != nil {
+		peers := findSignalPeers(node)
+
+		// 1. Explicit Definition Fields
+		var defNode *index.ProjectNode
+		for _, p := range peers {
+			if p.Parent != nil && p.Parent.Name == "Signals" {
+				defNode = p
+				break
+			}
+		}
+
+		if defNode != nil {
+			for _, frag := range defNode.Fragments {
+				for _, def := range frag.Definitions {
+					if f, ok := def.(*parser.Field); ok {
+						key := f.Name
+						if key != "Type" && key != "NumberOfElements" && key != "NumberOfDimensions" && key != "Class" {
+							val := valueToString(f.Value, defNode)
+							info += fmt.Sprintf("\n**%s**: `%s`", key, val)
+						}
+					}
+				}
+			}
+		}
+
+		extraInfo := ""
+		for _, p := range peers {
+			if (p.Parent.Name == "InputSignals" || p.Parent.Name == "OutputSignals") && isGAM(p.Parent.Parent) {
+				gamName := p.Parent.Parent.RealName
+				for _, frag := range p.Fragments {
+					for _, def := range frag.Definitions {
+						if f, ok := def.(*parser.Field); ok {
+							key := f.Name
+							if key != "DataSource" && key != "Alias" && key != "Type" && key != "Class" && key != "NumberOfElements" && key != "NumberOfDimensions" {
+								val := valueToString(f.Value, p)
+								extraInfo += fmt.Sprintf("\n- **%s** (%s): `%s`", key, gamName, val)
+							}
+						}
+					}
+				}
+			}
+		}
+		if extraInfo != "" {
+			info += "\n\n**Usage Details**:" + extraInfo
+		}
+	}
+
 	// Find references
 	var refs []string
 	for _, ref := range Tree.References {
@@ -1440,6 +1492,81 @@ func HandleRename(params RenameParams) *WorkspaceEdit {
 	}
 
 	if targetNode != nil {
+		// Special handling for Signals (Implicit/Explicit)
+		if ds, _ := getSignalInfo(targetNode); ds != nil {
+			peers := findSignalPeers(targetNode)
+			seenPeers := make(map[*index.ProjectNode]bool)
+
+			for _, peer := range peers {
+				if seenPeers[peer] {
+					continue
+				}
+				seenPeers[peer] = true
+
+				// Rename Peer Definition
+				prefix := ""
+				if len(peer.RealName) > 0 {
+					first := peer.RealName[0]
+					if first == '+' || first == '$' {
+						prefix = string(first)
+					}
+				}
+				normNewName := strings.TrimLeft(params.NewName, "+$")
+				finalDefName := prefix + normNewName
+
+				hasAlias := false
+				for _, frag := range peer.Fragments {
+					for _, def := range frag.Definitions {
+						if f, ok := def.(*parser.Field); ok && f.Name == "Alias" {
+							hasAlias = true
+						}
+					}
+				}
+
+				if !hasAlias {
+					for _, frag := range peer.Fragments {
+						if frag.IsObject {
+							rng := Range{
+								Start: Position{Line: frag.ObjectPos.Line - 1, Character: frag.ObjectPos.Column - 1},
+								End:   Position{Line: frag.ObjectPos.Line - 1, Character: frag.ObjectPos.Column - 1 + len(peer.RealName)},
+							}
+							addEdit(frag.File, rng, finalDefName)
+						}
+					}
+				}
+
+				// Rename References to this Peer
+				for _, ref := range Tree.References {
+					if ref.Target == peer {
+						// Handle qualified names
+						if strings.Contains(ref.Name, ".") {
+							if strings.HasSuffix(ref.Name, "."+peer.Name) {
+								prefixLen := len(ref.Name) - len(peer.Name)
+								rng := Range{
+									Start: Position{Line: ref.Position.Line - 1, Character: ref.Position.Column - 1 + prefixLen},
+									End:   Position{Line: ref.Position.Line - 1, Character: ref.Position.Column - 1 + len(ref.Name)},
+								}
+								addEdit(ref.File, rng, normNewName)
+							} else if ref.Name == peer.Name {
+								rng := Range{
+									Start: Position{Line: ref.Position.Line - 1, Character: ref.Position.Column - 1},
+									End:   Position{Line: ref.Position.Line - 1, Character: ref.Position.Column - 1 + len(ref.Name)},
+								}
+								addEdit(ref.File, rng, normNewName)
+							}
+						} else {
+							rng := Range{
+								Start: Position{Line: ref.Position.Line - 1, Character: ref.Position.Column - 1},
+								End:   Position{Line: ref.Position.Line - 1, Character: ref.Position.Column - 1 + len(ref.Name)},
+							}
+							addEdit(ref.File, rng, normNewName)
+						}
+					}
+				}
+			}
+			return &WorkspaceEdit{Changes: changes}
+		}
+
 		// 1. Rename Definitions
 		prefix := ""
 		if len(targetNode.RealName) > 0 {
@@ -1566,7 +1693,7 @@ func suggestVariables(container *index.ProjectNode) *CompletionList {
 
 				doc := ""
 				if info.Def.DefaultValue != nil {
-					doc = fmt.Sprintf("Default: %s", valueToString(info.Def.DefaultValue))
+					doc = fmt.Sprintf("Default: %s", valueToString(info.Def.DefaultValue, container))
 				}
 
 				items = append(items, CompletionItem{
@@ -1581,3 +1708,196 @@ func suggestVariables(container *index.ProjectNode) *CompletionList {
 	}
 	return &CompletionList{Items: items}
 }
+
+func getSignalInfo(node *index.ProjectNode) (*index.ProjectNode, string) {
+	if node.Parent == nil {
+		return nil, ""
+	}
+
+	// Case 1: Definition
+	if node.Parent.Name == "Signals" && isDataSource(node.Parent.Parent) {
+		return node.Parent.Parent, node.RealName
+	}
+
+	// Case 2: Usage
+	if (node.Parent.Name == "InputSignals" || node.Parent.Name == "OutputSignals") && isGAM(node.Parent.Parent) {
+		dsName := ""
+		sigName := node.RealName
+
+		// Scan fields
+		for _, frag := range node.Fragments {
+			for _, def := range frag.Definitions {
+				if f, ok := def.(*parser.Field); ok {
+					if f.Name == "DataSource" {
+						if v, ok := f.Value.(*parser.StringValue); ok {
+							dsName = v.Value
+						}
+						if v, ok := f.Value.(*parser.ReferenceValue); ok {
+							dsName = v.Value
+						}
+					}
+					if f.Name == "Alias" {
+						if v, ok := f.Value.(*parser.StringValue); ok {
+							sigName = v.Value
+						}
+						if v, ok := f.Value.(*parser.ReferenceValue); ok {
+							sigName = v.Value
+						}
+					}
+				}
+			}
+		}
+
+		if dsName != "" {
+			dsNode := Tree.ResolveName(node, dsName, isDataSource)
+			return dsNode, sigName
+		}
+	}
+	return nil, ""
+}
+
+func findSignalPeers(target *index.ProjectNode) []*index.ProjectNode {
+	dsNode, sigName := getSignalInfo(target)
+	if dsNode == nil || sigName == "" {
+		return nil
+	}
+
+	var peers []*index.ProjectNode
+
+	// Add definition if exists (and not already target)
+	if signals, ok := dsNode.Children["Signals"]; ok {
+		if def, ok := signals.Children[index.NormalizeName(sigName)]; ok {
+			peers = append(peers, def)
+		}
+	}
+
+	// Find usages
+	Tree.Walk(func(n *index.ProjectNode) {
+		d, s := getSignalInfo(n)
+		if d == dsNode && s == sigName {
+			peers = append(peers, n)
+		}
+	})
+
+	return peers
+}
+
+func evaluate(val parser.Value, ctx *index.ProjectNode) parser.Value {
+	switch v := val.(type) {
+	case *parser.VariableReferenceValue:
+		name := strings.TrimLeft(v.Name, "@")
+		if info := Tree.ResolveVariable(ctx, name); info != nil {
+			if info.Def.DefaultValue != nil {
+				return evaluate(info.Def.DefaultValue, ctx)
+			}
+		}
+		return v
+	case *parser.BinaryExpression:
+		left := evaluate(v.Left, ctx)
+		right := evaluate(v.Right, ctx)
+		return compute(left, v.Operator, right)
+	case *parser.UnaryExpression:
+		right := evaluate(v.Right, ctx)
+		return computeUnary(v.Operator, right)
+	}
+	return val
+}
+
+func compute(left parser.Value, op parser.Token, right parser.Value) parser.Value {
+	if op.Type == parser.TokenConcat {
+		getRaw := func(v parser.Value) string {
+			if s, ok := v.(*parser.StringValue); ok {
+				return s.Value
+			}
+			return valueToString(v, nil)
+		}
+		s1 := getRaw(left)
+		s2 := getRaw(right)
+		return &parser.StringValue{Value: s1 + s2, Quoted: true}
+	}
+
+	toInt := func(v parser.Value) (int64, bool) {
+		if idx, ok := v.(*parser.IntValue); ok {
+			return idx.Value, true
+		}
+		return 0, false
+	}
+	toFloat := func(v parser.Value) (float64, bool) {
+		if f, ok := v.(*parser.FloatValue); ok {
+			return f.Value, true
+		}
+		if idx, ok := v.(*parser.IntValue); ok {
+			return float64(idx.Value), true
+		}
+		return 0, false
+	}
+
+	lI, lIsI := toInt(left)
+	rI, rIsI := toInt(right)
+
+	if lIsI && rIsI {
+		var res int64
+		switch op.Type {
+		case parser.TokenPlus:
+			res = lI + rI
+		case parser.TokenMinus:
+			res = lI - rI
+		case parser.TokenStar:
+			res = lI * rI
+		case parser.TokenSlash:
+			if rI != 0 {
+				res = lI / rI
+			}
+		case parser.TokenPercent:
+			if rI != 0 {
+				res = lI % rI
+			}
+		case parser.TokenAmpersand:
+			res = lI & rI
+		case parser.TokenPipe:
+			res = lI | rI
+		case parser.TokenCaret:
+			res = lI ^ rI
+		}
+		return &parser.IntValue{Value: res, Raw: fmt.Sprintf("%d", res)}
+	}
+
+	lF, lIsF := toFloat(left)
+	rF, rIsF := toFloat(right)
+
+	if lIsF || rIsF {
+		var res float64
+		switch op.Type {
+		case parser.TokenPlus:
+			res = lF + rF
+		case parser.TokenMinus:
+			res = lF - rF
+		case parser.TokenStar:
+			res = lF * rF
+		case parser.TokenSlash:
+			res = lF / rF
+		}
+		return &parser.FloatValue{Value: res, Raw: fmt.Sprintf("%g", res)}
+	}
+
+	return left
+}
+
+func computeUnary(op parser.Token, val parser.Value) parser.Value {
+	switch op.Type {
+	case parser.TokenMinus:
+		if i, ok := val.(*parser.IntValue); ok {
+			return &parser.IntValue{Value: -i.Value, Raw: fmt.Sprintf("%d", -i.Value)}
+		}
+		if f, ok := val.(*parser.FloatValue); ok {
+			return &parser.FloatValue{Value: -f.Value, Raw: fmt.Sprintf("%g", -f.Value)}
+		}
+	case parser.TokenSymbol:
+		if op.Value == "!" {
+			if b, ok := val.(*parser.BoolValue); ok {
+				return &parser.BoolValue{Value: !b.Value}
+			}
+		}
+	}
+	return val
+}

internal/parser/parser.go

@@ -319,6 +319,13 @@ func (p *Parser) parseAtom() (Value, bool) {
 			}
 			return val, true
 		}
+		if tok.Value == "!" {
+			val, ok := p.parseAtom()
+			if !ok {
+				return nil, false
+			}
+			return &UnaryExpression{Position: tok.Position, Operator: tok, Right: val}, true
+		}
 		fallthrough
 	case TokenLBrace:
 		arr := &ArrayValue{Position: tok.Position}

internal/validator/validator.go

@@ -56,6 +56,7 @@ func (v *Validator) ValidateProject() {
 	v.CheckUnused()
 	v.CheckDataSourceThreading()
 	v.CheckINOUTOrdering()
+	v.CheckSignalConsistency()
 	v.CheckVariables()
 	v.CheckUnresolvedVariables()
 }
@@ -1233,6 +1234,93 @@ func (v *Validator) getDataSourceDirection(ds *index.ProjectNode) string {
 	return ""
 }
 
+func (v *Validator) CheckSignalConsistency() {
+	// Map: DataSourceNode -> SignalName -> List of Signals
+	signals := make(map[*index.ProjectNode]map[string][]*index.ProjectNode)
+
+	// Helper to collect signals
+	collect := func(node *index.ProjectNode) {
+		if !isGAM(node) {
+			return
+		}
+		// Check Input and Output
+		for _, dir := range []string{"InputSignals", "OutputSignals"} {
+			if container, ok := node.Children[dir]; ok {
+				for _, sig := range container.Children {
+					fields := v.getFields(sig)
+					var dsNode *index.ProjectNode
+					var sigName string
+
+					// Resolve DS
+					if dsFields, ok := fields["DataSource"]; ok && len(dsFields) > 0 {
+						dsName := v.getFieldValue(dsFields[0], sig)
+						if dsName != "" {
+							dsNode = v.resolveReference(dsName, sig, isDataSource)
+						}
+					}
+
+					// Resolve Name (Alias or RealName)
+					if aliasFields, ok := fields["Alias"]; ok && len(aliasFields) > 0 {
+						sigName = v.getFieldValue(aliasFields[0], sig)
+					} else {
+						sigName = sig.RealName
+					}
+
+					if dsNode != nil && sigName != "" {
+						sigName = index.NormalizeName(sigName)
+						if signals[dsNode] == nil {
+							signals[dsNode] = make(map[string][]*index.ProjectNode)
+						}
+						signals[dsNode][sigName] = append(signals[dsNode][sigName], sig)
+					}
+				}
+			}
+		}
+	}
+
+	v.Tree.Walk(collect)
+
+	// Check Consistency
+	for ds, sigMap := range signals {
+		for sigName, usages := range sigMap {
+			if len(usages) <= 1 {
+				continue
+			}
+
+			// Check Type consistency
+			var firstType string
+			var firstNode *index.ProjectNode
+
+			for _, u := range usages {
+				// Get Type
+				typeVal := ""
+				fields := v.getFields(u)
+				if typeFields, ok := fields["Type"]; ok && len(typeFields) > 0 {
+					typeVal = v.getFieldValue(typeFields[0], u)
+				}
+
+				if typeVal == "" {
+					continue
+				}
+
+				if firstNode == nil {
+					firstType = typeVal
+					firstNode = u
+				} else {
+					if typeVal != firstType {
+						v.Diagnostics = append(v.Diagnostics, Diagnostic{
+							Level:   LevelError,
+							Message: fmt.Sprintf("Signal Type Mismatch: Signal '%s' (in DS '%s') is defined as '%s' in '%s' but as '%s' in '%s'", sigName, ds.RealName, firstType, firstNode.Parent.Parent.RealName, typeVal, u.Parent.Parent.RealName),
+							Position: v.getNodePosition(u),
+							File:     v.getNodeFile(u),
+						})
+					}
+				}
+			}
+		}
+	}
+}
+
 func (v *Validator) CheckVariables() {
 	if v.Schema == nil {
 		return

test/builder_merge_test.go

@@ -0,0 +1,56 @@
+package integration
+
+import (
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/builder"
+)
+
+func TestBuilderMergeNodes(t *testing.T) {
+	// Two files without package, defining SAME root node +App.
+	// This triggers merging logic in Builder.
+	
+	content1 := `
++App = {
+    Field1 = 10
+    +Sub = { Val = 1 }
+}
+`
+	content2 := `
++App = {
+    Field2 = 20
+    +Sub = { Val2 = 2 }
+}
+`
+	f1, _ := os.CreateTemp("", "merge1.marte")
+	f1.WriteString(content1)
+	f1.Close()
+	defer os.Remove(f1.Name())
+
+	f2, _ := os.CreateTemp("", "merge2.marte")
+	f2.WriteString(content2)
+	f2.Close()
+	defer os.Remove(f2.Name())
+
+	b := builder.NewBuilder([]string{f1.Name(), f2.Name()}, nil)
+
+	outF, _ := os.CreateTemp("", "out_merge.marte")
+	defer os.Remove(outF.Name())
+	
+	err := b.Build(outF)
+	if err != nil {
+		t.Fatalf("Build failed: %v", err)
+	}
+	outF.Close()
+
+	outContent, _ := os.ReadFile(outF.Name())
+	outStr := string(outContent)
+
+	if !strings.Contains(outStr, "Field1 = 10") { t.Error("Missing Field1") }
+	if !strings.Contains(outStr, "Field2 = 20") { t.Error("Missing Field2") }
+	if !strings.Contains(outStr, "+Sub = {") { t.Error("Missing Sub") }
+	if !strings.Contains(outStr, "Val = 1") { t.Error("Missing Sub.Val") }
+	if !strings.Contains(outStr, "Val2 = 2") { t.Error("Missing Sub.Val2") }
+}

test/formatter_coverage_test.go

@@ -0,0 +1,55 @@
+package integration
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/formatter"
+	"github.com/marte-community/marte-dev-tools/internal/parser"
+)
+
+func TestFormatterCoverage(t *testing.T) {
+	content := `
+// Head comment
+#package Pkg
+
+//# Doc for A
++A = {
+    Field = 10 // Trailing
+    Bool = true
+    Float = 1.23
+    Ref = SomeObj
+    Array = { 1 2 3 }
+    Expr = 1 + 2
+    
+    // Inner
+    +B = {
+        Val = "Str"
+    }
+}
+
+// Final
+`
+	p := parser.NewParser(content)
+	cfg, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	var buf bytes.Buffer
+	formatter.Format(cfg, &buf)
+
+	out := buf.String()
+	if !strings.Contains(out, "Field = 10") {
+		t.Error("Formatting failed")
+	}
+
+	// Check comments
+	if !strings.Contains(out, "// Head comment") {
+		t.Error("Head comment missing")
+	}
+	if !strings.Contains(out, "//# Doc for A") {
+		t.Error("Doc missing")
+	}
+}

test/lexer_coverage_test.go

@@ -0,0 +1,45 @@
+package integration
+
+import (
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/parser"
+)
+
+func TestLexerCoverage(t *testing.T) {
+	// 1. Comments
+	input := `
+// Line comment
+/* Block comment */
+//# Docstring
+//! Pragma
+/* Unclosed block
+`
+	l := parser.NewLexer(input)
+	for {
+		tok := l.NextToken()
+		if tok.Type == parser.TokenEOF {
+			break
+		}
+	}
+
+	// 2. Numbers
+	inputNum := `123 12.34 1.2e3 1.2E-3 0xFF`
+	lNum := parser.NewLexer(inputNum)
+	for {
+		tok := lNum.NextToken()
+		if tok.Type == parser.TokenEOF {
+			break
+		}
+	}
+
+	// 3. Identifiers
+	inputID := `Valid ID with-hyphen _under`
+	lID := parser.NewLexer(inputID)
+	for {
+		tok := lID.NextToken()
+		if tok.Type == parser.TokenEOF {
+			break
+		}
+	}
+}

test/logger_test.go

@@ -10,6 +10,9 @@ import (
 )
 
 func TestLoggerPrint(t *testing.T) {
+	// Direct call for coverage
+	logger.Println("Coverage check")
+
 	if os.Getenv("TEST_LOGGER_PRINT") == "1" {
 		logger.Printf("Test Printf %d", 123)
 		logger.Println("Test Println")

test/lsp_completion_test.go

@@ -352,12 +352,12 @@ package schema
 			t.Error("Expected @MyVar in suggestions for =")
 		}
 
-		// 2. Triggered by $
+		// 2. Triggered by @
-		// "Field = $"
+		// "Field = @"
 		lsp.Documents[uri] = `
 #var MyVar: uint = 10
 +App = {
-    Field = $
+    Field = @
 }
 `
 		params2 := lsp.CompletionParams{
@@ -366,7 +366,7 @@ package schema
 		}
 		list2 := lsp.HandleCompletion(params2)
 		if list2 == nil {
-			t.Fatal("Expected suggestions for $")
+			t.Fatal("Expected suggestions for @")
 		}
 		found = false
 		for _, item := range list2.Items {
@@ -376,7 +376,7 @@ package schema
 			}
 		}
 		if !found {
-			t.Error("Expected MyVar in suggestions for $")
+			t.Error("Expected MyVar in suggestions for @")
 		}
 	})
 }

test/lsp_coverage_test.go

@@ -8,7 +8,9 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/marte-community/marte-dev-tools/internal/index"
 	"github.com/marte-community/marte-dev-tools/internal/lsp"
+	"github.com/marte-community/marte-dev-tools/internal/parser"
 )
 
 func TestLSPIncrementalSync(t *testing.T) {
@@ -108,3 +110,82 @@ func TestLSPMalformedParams(t *testing.T) {
 		t.Errorf("Expected nil result for malformed params, got: %s", output)
 	}
 }
+
+func TestLSPDispatch(t *testing.T) {
+	var buf bytes.Buffer
+	lsp.Output = &buf
+
+	// Initialize
+	msgInit := &lsp.JsonRpcMessage{Method: "initialize", ID: 1, Params: json.RawMessage(`{}`)}
+	lsp.HandleMessage(msgInit)
+
+	// DidOpen
+	msgOpen := &lsp.JsonRpcMessage{Method: "textDocument/didOpen", Params: json.RawMessage(`{"textDocument":{"uri":"file://d.marte","text":""}}`)}
+	lsp.HandleMessage(msgOpen)
+
+	// DidChange
+	msgChange := &lsp.JsonRpcMessage{Method: "textDocument/didChange", Params: json.RawMessage(`{"textDocument":{"uri":"file://d.marte","version":2},"contentChanges":[{"text":"A"}]}`)}
+	lsp.HandleMessage(msgChange)
+
+	// Hover
+	msgHover := &lsp.JsonRpcMessage{Method: "textDocument/hover", ID: 2, Params: json.RawMessage(`{"textDocument":{"uri":"file://d.marte"},"position":{"line":0,"character":0}}`)}
+	lsp.HandleMessage(msgHover)
+
+	// Definition
+	msgDef := &lsp.JsonRpcMessage{Method: "textDocument/definition", ID: 3, Params: json.RawMessage(`{"textDocument":{"uri":"file://d.marte"},"position":{"line":0,"character":0}}`)}
+	lsp.HandleMessage(msgDef)
+
+	// References
+	msgRef := &lsp.JsonRpcMessage{Method: "textDocument/references", ID: 4, Params: json.RawMessage(`{"textDocument":{"uri":"file://d.marte"},"position":{"line":0,"character":0},"context":{"includeDeclaration":true}}`)}
+	lsp.HandleMessage(msgRef)
+
+	// Completion
+	msgComp := &lsp.JsonRpcMessage{Method: "textDocument/completion", ID: 5, Params: json.RawMessage(`{"textDocument":{"uri":"file://d.marte"},"position":{"line":0,"character":0}}`)}
+	lsp.HandleMessage(msgComp)
+
+	// Formatting
+	msgFmt := &lsp.JsonRpcMessage{Method: "textDocument/formatting", ID: 6, Params: json.RawMessage(`{"textDocument":{"uri":"file://d.marte"},"options":{"tabSize":4,"insertSpaces":true}}`)}
+	lsp.HandleMessage(msgFmt)
+
+	// Rename
+	msgRename := &lsp.JsonRpcMessage{Method: "textDocument/rename", ID: 7, Params: json.RawMessage(`{"textDocument":{"uri":"file://d.marte"},"position":{"line":0,"character":0},"newName":"B"}`)}
+	lsp.HandleMessage(msgRename)
+}
+
+func TestLSPVariableDefinition(t *testing.T) {
+	lsp.Tree = index.NewProjectTree()
+	lsp.Documents = make(map[string]string)
+	
+	content := `
+#var MyVar: int = 10
++Obj = {
+    Field = @MyVar
+}
+`
+	uri := "file://var_def.marte"
+	lsp.Documents[uri] = content
+	
+	p := parser.NewParser(content)
+	cfg, _ := p.Parse()
+	lsp.Tree.AddFile("var_def.marte", cfg)
+	lsp.Tree.ResolveReferences()
+	
+	params := lsp.DefinitionParams{
+		TextDocument: lsp.TextDocumentIdentifier{URI: uri},
+		Position:     lsp.Position{Line: 3, Character: 13},
+	}
+	
+	res := lsp.HandleDefinition(params)
+	if res == nil {
+		t.Fatal("Definition not found for variable")
+	}
+	
+	locs, ok := res.([]lsp.Location)
+	if !ok || len(locs) == 0 {
+		t.Fatal("Expected location list")
+	}
+	
+	if locs[0].Range.Start.Line != 1 {
+		t.Errorf("Expected line 1, got %d", locs[0].Range.Start.Line)
+	}
+}

test/operators_test.go

@@ -15,11 +15,23 @@ func TestOperators(t *testing.T) {
 #var B: int = 20
 #var S1: string = "Hello"
 #var S2: string = "World"
+#var FA: float = 1.5
+#var FB: float = 2.0
 
 +Obj = {
     Math = @A + @B
     Precedence = @A + @B * 2
     Concat = @S1 .. " " .. @S2
+    FloatMath = @FA + @FB
+    Mix = @A + @FA
+    ConcatNum = "Num: " .. @A
+    ConcatFloat = "F: " .. @FA
+    ConcatArr = "A: " .. { 1 }
+    BoolVal = true
+    RefVal = Obj
+    ArrVal = { 1 2 }
+    Unres = @Unknown
+    InvalidMath = "A" + 1
 }
 `
 	// Check Parser
@@ -55,4 +67,26 @@ func TestOperators(t *testing.T) {
 	if !strings.Contains(outStr, "Concat = \"Hello World\"") {
 		t.Errorf("Concat failed. Got:\n%s", outStr)
 	}
-}
+	if !strings.Contains(outStr, "FloatMath = 3.5") {
+		t.Errorf("FloatMath failed. Got:\n%s", outStr)
+	}
+	// 10 + 1.5 = 11.5
+	if !strings.Contains(outStr, "Mix = 11.5") {
+		t.Errorf("Mix failed. Got:\n%s", outStr)
+	}
+	if !strings.Contains(outStr, "ConcatNum = \"Num: 10\"") {
+		t.Errorf("ConcatNum failed. Got:\n%s", outStr)
+	}
+	if !strings.Contains(outStr, "BoolVal = true") {
+		t.Errorf("BoolVal failed. Got:\n%s", outStr)
+	}
+	if !strings.Contains(outStr, "RefVal = Obj") {
+		t.Errorf("RefVal failed. Got:\n%s", outStr)
+	}
+	if !strings.Contains(outStr, "ArrVal = { 1 2 }") {
+		t.Errorf("ArrVal failed. Got:\n%s", outStr)
+	}
+	if !strings.Contains(outStr, "Unres = @Unknown") {
+		t.Errorf("Unres failed. Got:\n%s", outStr)
+	}
+}

test/validator_expression_test.go

@@ -0,0 +1,84 @@
+package integration
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/index"
+	"github.com/marte-community/marte-dev-tools/internal/parser"
+	"github.com/marte-community/marte-dev-tools/internal/schema"
+	"github.com/marte-community/marte-dev-tools/internal/validator"
+)
+
+func TestValidatorExpressionCoverage(t *testing.T) {
+	content := `
+#var A: int = 10
+#var B: int = 5
+#var S1: string = "Hello"
+#var S2: string = "World"
+
+// Valid cases (execution hits evaluateBinary)
+#var Sum: int = @A + @B // 15
+#var Sub: int = @A - @B // 5
+#var Mul: int = @A * @B // 50
+#var Div: int = @A / @B // 2
+#var Mod: int = @A % 3  // 1
+#var Concat: string = @S1 .. " " .. @S2 // "Hello World"
+#var Unary: int = -@A // -10
+#var BitAnd: int = 10 & 5
+#var BitOr: int = 10 | 5
+#var BitXor: int = 10 ^ 5
+
+#var FA: float = 1.5
+#var FB: float = 2.0
+#var FSum: float = @FA + @FB // 3.5
+#var FSub: float = @FB - @FA // 0.5
+#var FMul: float = @FA * @FB // 3.0
+#var FDiv: float = @FB / @FA // 1.333...
+
+#var BT: bool = true
+#var BF: bool = !@BT
+
+// Invalid cases (should error)
+#var BadSum: int & > 20 = @A + @B // 15, should fail
+#var BadUnary: bool = !10 // Should fail type check (nil result from evaluateUnary)
+#var StrVar: string = "DS"
+
++InvalidDS = {
+    Class = IOGAM
+    InputSignals = {
+        S = { DataSource = 10 } // Int coverage
+        S2 = { DataSource = 1.5 } // Float coverage
+        S3 = { DataSource = true } // Bool coverage
+        S4 = { DataSource = @StrVar } // VarRef coverage -> String
+        S5 = { DataSource = { 1 } } // Array coverage (default case)
+    }
+    OutputSignals = {}
+}
+`
+	pt := index.NewProjectTree()
+	p := parser.NewParser(content)
+	cfg, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+	pt.AddFile("expr.marte", cfg)
+	pt.ResolveReferences()
+
+	v := validator.NewValidator(pt, ".")
+	// Use NewSchema to ensure basic types
+	v.Schema = schema.NewSchema()
+
+	v.CheckVariables()
+
+	// Check for expected errors
+	foundBadSum := false
+	for _, diag := range v.Diagnostics {
+		if strings.Contains(diag.Message, "BadSum") && strings.Contains(diag.Message, "value mismatch") {
+			foundBadSum = true
+		}
+	}
+	if !foundBadSum {
+		t.Error("Expected error for BadSum")
+	}
+}