simple makefile

.gitignore

@@ -1,3 +1,4 @@
 build
 *.log
 mdt
+*.out

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 MARTe Community
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -0,0 +1,24 @@
+BINARY_NAME=mdt
+BUILD_DIR=build
+
+.PHONY: all build test coverage clean install
+
+all: test build
+
+build:
+	mkdir -p $(BUILD_DIR)
+	go build -o $(BUILD_DIR)/$(BINARY_NAME) ./cmd/mdt
+
+test:
+	go test -v ./...
+
+coverage:
+	go test -cover -coverprofile=coverage.out ./test/... -coverpkg=./internal/...
+	go tool cover -func=coverage.out
+
+clean:
+	rm -rf $(BUILD_DIR)
+	rm -f coverage.out
+
+install:
+	go install ./cmd/mdt

README.md

@@ -0,0 +1,96 @@
+# MARTe Development Tools (mdt)
+
+`mdt` is a comprehensive toolkit for developing, validating, and building configurations for the MARTe real-time framework. It provides a CLI and a Language Server Protocol (LSP) server to enhance the development experience.
+
+## Features
+
+- **LSP Server**: Real-time syntax checking, validation, autocomplete, hover documentation, and navigation (Go to Definition/References).
+- **Builder**: Merges multiple configuration files into a single, ordered output file.
+- **Formatter**: Standardizes configuration file formatting.
+- **Validator**: Advanced semantic validation using [CUE](https://cuelang.org/) schemas, ensuring type safety and structural correctness.
+
+## Installation
+
+### From Source
+
+Requirements: Go 1.21+
+
+```bash
+go install github.com/marte-community/marte-dev-tools/cmd/mdt@latest
+```
+
+## Usage
+
+### CLI Commands
+
+- **Check**: Run validation on a file or project.
+  ```bash
+  mdt check path/to/project
+  ```
+- **Build**: Merge project files into a single output.
+  ```bash
+  mdt build -o output.marte main.marte
+  ```
+- **Format**: Format configuration files.
+  ```bash
+  mdt fmt path/to/file.marte
+  ```
+- **LSP**: Start the language server (used by editor plugins).
+  ```bash
+  mdt lsp
+  ```
+
+### Editor Integration
+
+`mdt lsp` implements the Language Server Protocol. You can use it with any LSP-compatible editor (VS Code, Neovim, Emacs, etc.).
+
+## MARTe Configuration
+
+The tools support the MARTe configuration format with extended features:
+- **Objects**: `+Node = { Class = ... }`
+- **Signals**: `Signal = { Type = ... }`
+- **Namespaces**: `#package PROJECT.NODE` for organizing multi-file projects.
+
+### Validation & Schema
+
+Validation is fully schema-driven using CUE.
+
+- **Built-in Schema**: Covers standard MARTe classes (`StateMachine`, `GAM`, `DataSource`, `RealTimeApplication`, etc.).
+- **Custom Schema**: Add a `.marte_schema.cue` file to your project root to extend or override definitions.
+
+**Example `.marte_schema.cue`:**
+```cue
+package schema
+
+#Classes: {
+    MyCustomGAM: {
+        Param1: int
+        Param2?: string
+        ...
+    }
+}
+```
+
+### Pragmas (Suppressing Warnings)
+
+Use comments starting with `//!` to control validation behavior:
+
+- `//!unused: Reason` - Suppress "Unused GAM" or "Unused Signal" warnings.
+- `//!implicit: Reason` - Suppress "Implicitly Defined Signal" warnings.
+- `//!cast(DefinedType, UsageType)` - Allow type mismatch between definition and usage (e.g. `//!cast(uint32, int32)`).
+- `//!allow(unused)` - Global suppression for the file.
+
+## Development
+
+### Building
+```bash
+go build ./cmd/mdt
+```
+
+### Running Tests
+```bash
+go test ./...
+```
+
+## License
+MIT

internal/lsp/server.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"regexp"
 	"strings"
 
 	"github.com/marte-community/marte-dev-tools/internal/formatter"
@@ -46,10 +47,10 @@ type CompletionList struct {
 	Items        []CompletionItem `json:"items"`
 }
 
-var tree = index.NewProjectTree()
-var documents = make(map[string]string)
-var projectRoot string
-var globalSchema *schema.Schema
+var Tree = index.NewProjectTree()
+var Documents = make(map[string]string)
+var ProjectRoot string
+var GlobalSchema *schema.Schema
 
 type JsonRpcMessage struct {
 	Jsonrpc string          `json:"jsonrpc"`
@@ -183,7 +184,7 @@ func RunServer() {
 			continue
 		}
 
-		handleMessage(msg)
+		HandleMessage(msg)
 	}
 }
 
@@ -213,7 +214,7 @@ func readMessage(reader *bufio.Reader) (*JsonRpcMessage, error) {
 	return &msg, err
 }
 
-func handleMessage(msg *JsonRpcMessage) {
+func HandleMessage(msg *JsonRpcMessage) {
 	switch msg.Method {
 	case "initialize":
 		var params InitializeParams
@@ -226,13 +227,13 @@ func handleMessage(msg *JsonRpcMessage) {
 			}
 
 			if root != "" {
-				projectRoot = root
+				ProjectRoot = root
 				logger.Printf("Scanning workspace: %s\n", root)
-				if err := tree.ScanDirectory(root); err != nil {
+				if err := Tree.ScanDirectory(root); err != nil {
 					logger.Printf("ScanDirectory failed: %v\n", err)
 				}
-				tree.ResolveReferences()
-				globalSchema = schema.LoadFullSchema(projectRoot)
+				Tree.ResolveReferences()
+				GlobalSchema = schema.LoadFullSchema(ProjectRoot)
 			}
 		}
 
@@ -257,18 +258,18 @@ func handleMessage(msg *JsonRpcMessage) {
 	case "textDocument/didOpen":
 		var params DidOpenTextDocumentParams
 		if err := json.Unmarshal(msg.Params, &params); err == nil {
-			handleDidOpen(params)
+			HandleDidOpen(params)
 		}
 	case "textDocument/didChange":
 		var params DidChangeTextDocumentParams
 		if err := json.Unmarshal(msg.Params, &params); err == nil {
-			handleDidChange(params)
+			HandleDidChange(params)
 		}
 	case "textDocument/hover":
 		var params HoverParams
 		if err := json.Unmarshal(msg.Params, &params); err == nil {
 			logger.Printf("Hover: %s:%d", params.TextDocument.URI, params.Position.Line)
-			res := handleHover(params)
+			res := HandleHover(params)
 			if res != nil {
 				logger.Printf("Res: %v", res.Contents)
 			} else {
@@ -282,22 +283,22 @@ func handleMessage(msg *JsonRpcMessage) {
 	case "textDocument/definition":
 		var params DefinitionParams
 		if err := json.Unmarshal(msg.Params, &params); err == nil {
-			respond(msg.ID, handleDefinition(params))
+			respond(msg.ID, HandleDefinition(params))
 		}
 	case "textDocument/references":
 		var params ReferenceParams
 		if err := json.Unmarshal(msg.Params, &params); err == nil {
-			respond(msg.ID, handleReferences(params))
+			respond(msg.ID, HandleReferences(params))
 		}
 	case "textDocument/completion":
 		var params CompletionParams
 		if err := json.Unmarshal(msg.Params, &params); err == nil {
-			respond(msg.ID, handleCompletion(params))
+			respond(msg.ID, HandleCompletion(params))
 		}
 	case "textDocument/formatting":
 		var params DocumentFormattingParams
 		if err := json.Unmarshal(msg.Params, &params); err == nil {
-			respond(msg.ID, handleFormatting(params))
+			respond(msg.ID, HandleFormatting(params))
 		}
 	}
 }
@@ -306,41 +307,51 @@ func uriToPath(uri string) string {
 	return strings.TrimPrefix(uri, "file://")
 }
 
-func handleDidOpen(params DidOpenTextDocumentParams) {
+func HandleDidOpen(params DidOpenTextDocumentParams) {
 	path := uriToPath(params.TextDocument.URI)
-	documents[params.TextDocument.URI] = params.TextDocument.Text
+	Documents[params.TextDocument.URI] = params.TextDocument.Text
 	p := parser.NewParser(params.TextDocument.Text)
 	config, err := p.Parse()
+
 	if err != nil {
 		publishParserError(params.TextDocument.URI, err)
-		return
+	} else {
+		publishParserError(params.TextDocument.URI, nil)
+	}
+
+	if config != nil {
+		Tree.AddFile(path, config)
+		Tree.ResolveReferences()
+		runValidation(params.TextDocument.URI)
 	}
-	tree.AddFile(path, config)
-	tree.ResolveReferences()
-	runValidation(params.TextDocument.URI)
 }
 
-func handleDidChange(params DidChangeTextDocumentParams) {
+func HandleDidChange(params DidChangeTextDocumentParams) {
 	if len(params.ContentChanges) == 0 {
 		return
 	}
 	text := params.ContentChanges[0].Text
-	documents[params.TextDocument.URI] = text
+	Documents[params.TextDocument.URI] = text
 	path := uriToPath(params.TextDocument.URI)
 	p := parser.NewParser(text)
 	config, err := p.Parse()
+
 	if err != nil {
 		publishParserError(params.TextDocument.URI, err)
-		return
+	} else {
+		publishParserError(params.TextDocument.URI, nil)
+	}
+
+	if config != nil {
+		Tree.AddFile(path, config)
+		Tree.ResolveReferences()
+		runValidation(params.TextDocument.URI)
 	}
-	tree.AddFile(path, config)
-	tree.ResolveReferences()
-	runValidation(params.TextDocument.URI)
 }
 
-func handleFormatting(params DocumentFormattingParams) []TextEdit {
+func HandleFormatting(params DocumentFormattingParams) []TextEdit {
 	uri := params.TextDocument.URI
-	text, ok := documents[uri]
+	text, ok := Documents[uri]
 	if !ok {
 		return nil
 	}
@@ -372,7 +383,7 @@ func handleFormatting(params DocumentFormattingParams) []TextEdit {
 }
 
 func runValidation(uri string) {
-	v := validator.NewValidator(tree, projectRoot)
+	v := validator.NewValidator(Tree, ProjectRoot)
 	v.ValidateProject()
 	v.CheckUnused()
 
@@ -381,7 +392,7 @@ func runValidation(uri string) {
 
 	// Collect all known files to ensure we clear diagnostics for fixed files
 	knownFiles := make(map[string]bool)
-	collectFiles(tree.Root, knownFiles)
+	collectFiles(Tree.Root, knownFiles)
 
 	// Initialize all known files with empty diagnostics
 	for f := range knownFiles {
@@ -426,6 +437,19 @@ func runValidation(uri string) {
 }
 
 func publishParserError(uri string, err error) {
+	if err == nil {
+		notification := JsonRpcMessage{
+			Jsonrpc: "2.0",
+			Method:  "textDocument/publishDiagnostics",
+			Params: mustMarshal(PublishDiagnosticsParams{
+				URI:         uri,
+				Diagnostics: []LSPDiagnostic{},
+			}),
+		}
+		send(notification)
+		return
+	}
+
 	var line, col int
 	var msg string
 	// Try parsing "line:col: message"
@@ -477,12 +501,12 @@ func mustMarshal(v any) json.RawMessage {
 	return b
 }
 
-func handleHover(params HoverParams) *Hover {
+func HandleHover(params HoverParams) *Hover {
 	path := uriToPath(params.TextDocument.URI)
 	line := params.Position.Line + 1
 	col := params.Position.Character + 1
 
-	res := tree.Query(path, line, col)
+	res := Tree.Query(path, line, col)
 	if res == nil {
 		logger.Printf("No object/node/reference found")
 		return nil
@@ -529,10 +553,10 @@ func handleHover(params HoverParams) *Hover {
 	}
 }
 
-func handleCompletion(params CompletionParams) *CompletionList {
+func HandleCompletion(params CompletionParams) *CompletionList {
 	uri := params.TextDocument.URI
 	path := uriToPath(uri)
-	text, ok := documents[uri]
+	text, ok := Documents[uri]
 	if !ok {
 		return nil
 	}
@@ -552,22 +576,30 @@ func handleCompletion(params CompletionParams) *CompletionList {
 
 	// Case 1: Assigning a value (Ends with "=" or "= ")
 	if strings.Contains(prefix, "=") {
-		parts := strings.Split(prefix, "=")
-		key := strings.TrimSpace(parts[len(parts)-2])
+		lastIdx := strings.LastIndex(prefix, "=")
+		beforeEqual := prefix[:lastIdx]
+
+		// Find the last identifier before '='
+		key := ""
+		re := regexp.MustCompile(`[a-zA-Z][a-zA-Z0-9_\-]*`)
+		matches := re.FindAllString(beforeEqual, -1)
+		if len(matches) > 0 {
+			key = matches[len(matches)-1]
+		}
 
 		if key == "Class" {
 			return suggestClasses()
 		}
 
-		container := tree.GetNodeContaining(path, parser.Position{Line: params.Position.Line + 1, Column: col + 1})
+		container := Tree.GetNodeContaining(path, parser.Position{Line: params.Position.Line + 1, Column: col + 1})
 		if container != nil {
-			return suggestFieldValues(container, key)
+			return suggestFieldValues(container, key, path)
 		}
 		return nil
 	}
 
 	// Case 2: Typing a key inside an object
-	container := tree.GetNodeContaining(path, parser.Position{Line: params.Position.Line + 1, Column: col + 1})
+	container := Tree.GetNodeContaining(path, parser.Position{Line: params.Position.Line + 1, Column: col + 1})
 	if container != nil {
 		return suggestFields(container)
 	}
@@ -576,11 +608,11 @@ func handleCompletion(params CompletionParams) *CompletionList {
 }
 
 func suggestClasses() *CompletionList {
-	if globalSchema == nil {
+	if GlobalSchema == nil {
 		return nil
 	}
 
-	classesVal := globalSchema.Value.LookupPath(cue.ParsePath("#Classes"))
+	classesVal := GlobalSchema.Value.LookupPath(cue.ParsePath("#Classes"))
 	if classesVal.Err() != nil {
 		return nil
 	}
@@ -615,11 +647,11 @@ func suggestFields(container *index.ProjectNode) *CompletionList {
 		}}}
 	}
 
-	if globalSchema == nil {
+	if GlobalSchema == nil {
 		return nil
 	}
 	classPath := cue.ParsePath(fmt.Sprintf("#Classes.%s", cls))
-	classVal := globalSchema.Value.LookupPath(classPath)
+	classVal := GlobalSchema.Value.LookupPath(classPath)
 	if classVal.Err() != nil {
 		return nil
 	}
@@ -677,19 +709,107 @@ func suggestFields(container *index.ProjectNode) *CompletionList {
 	return &CompletionList{Items: items}
 }
 
-func suggestFieldValues(container *index.ProjectNode, field string) *CompletionList {
+func suggestFieldValues(container *index.ProjectNode, field string, path string) *CompletionList {
+	var root *index.ProjectNode
+	if iso, ok := Tree.IsolatedFiles[path]; ok {
+		root = iso
+	} else {
+		root = Tree.Root
+	}
+
 	if field == "DataSource" {
-		return suggestObjects("DataSource")
+		return suggestObjects(root, "DataSource")
 	}
 	if field == "Functions" {
-		return suggestObjects("GAM")
+		return suggestObjects(root, "GAM")
+	}
+	if field == "Type" {
+		return suggestSignalTypes()
+	}
+
+	if list := suggestCUEEnums(container, field); list != nil {
+		return list
+	}
+
+	return nil
+}
+
+func suggestSignalTypes() *CompletionList {
+	types := []string{
+		"uint8", "int8", "uint16", "int16", "uint32", "int32", "uint64", "int64",
+		"float32", "float64", "string", "bool", "char8",
+	}
+	var items []CompletionItem
+	for _, t := range types {
+		items = append(items, CompletionItem{
+			Label:  t,
+			Kind:   13, // EnumMember
+			Detail: "Signal Type",
+		})
+	}
+	return &CompletionList{Items: items}
+}
+
+func suggestCUEEnums(container *index.ProjectNode, field string) *CompletionList {
+	if GlobalSchema == nil {
+		return nil
+	}
+	cls := container.Metadata["Class"]
+	if cls == "" {
+		return nil
+	}
+
+	classPath := cue.ParsePath(fmt.Sprintf("#Classes.%s.%s", cls, field))
+	val := GlobalSchema.Value.LookupPath(classPath)
+	if val.Err() != nil {
+		return nil
+	}
+
+	op, args := val.Expr()
+	var values []cue.Value
+	if op == cue.OrOp {
+		values = args
+	} else {
+		values = []cue.Value{val}
+	}
+
+	var items []CompletionItem
+	for _, v := range values {
+		if !v.IsConcrete() {
+			continue
+		}
+
+		str, err := v.String() // Returns quoted string for string values?
+		if err != nil {
+			continue
+		}
+        
+        // Ensure strings are quoted
+        if v.Kind() == cue.StringKind && !strings.HasPrefix(str, "\"") {
+            str = fmt.Sprintf("\"%s\"", str)
+        }
+
+		items = append(items, CompletionItem{
+			Label:  str,
+			Kind:   13, // EnumMember
+			Detail: "Enum Value",
+		})
+	}
+
+	if len(items) > 0 {
+		return &CompletionList{Items: items}
 	}
 	return nil
 }
 
-func suggestObjects(filter string) *CompletionList {
+func suggestObjects(root *index.ProjectNode, filter string) *CompletionList {
+	if root == nil {
+		return nil
+	}
 	var items []CompletionItem
-	tree.Walk(func(node *index.ProjectNode) {
+
+	var walk func(*index.ProjectNode)
+	walk = func(node *index.ProjectNode) {
 		match := false
 		if filter == "GAM" {
 			if isGAM(node) {
@@ -703,12 +823,18 @@ func suggestObjects(filter string) *CompletionList {
 
 		if match {
 			items = append(items, CompletionItem{
-				Label:  node.RealName,
+				Label:  node.Name,
 				Kind:   6, // Variable
 				Detail: node.Metadata["Class"],
 			})
 		}
-	})
+
+		for _, child := range node.Children {
+			walk(child)
+		}
+	}
+
+	walk(root)
 	return &CompletionList{Items: items}
 }
 
@@ -729,12 +855,12 @@ func isDataSource(node *index.ProjectNode) bool {
 	return hasSignals
 }
 
-func handleDefinition(params DefinitionParams) any {
+func HandleDefinition(params DefinitionParams) any {
 	path := uriToPath(params.TextDocument.URI)
 	line := params.Position.Line + 1
 	col := params.Position.Character + 1
 
-	res := tree.Query(path, line, col)
+	res := Tree.Query(path, line, col)
 	if res == nil {
 		return nil
 	}
@@ -769,12 +895,12 @@ func handleDefinition(params DefinitionParams) any {
 	return nil
 }
 
-func handleReferences(params ReferenceParams) []Location {
+func HandleReferences(params ReferenceParams) []Location {
 	path := uriToPath(params.TextDocument.URI)
 	line := params.Position.Line + 1
 	col := params.Position.Character + 1
 
-	res := tree.Query(path, line, col)
+	res := Tree.Query(path, line, col)
 	if res == nil {
 		return nil
 	}
@@ -812,7 +938,7 @@ func handleReferences(params ReferenceParams) []Location {
 	}
 
 	// 1. References from index (Aliases)
-	for _, ref := range tree.References {
+	for _, ref := range Tree.References {
 		if ref.Target == canonical {
 			locations = append(locations, Location{
 				URI: "file://" + ref.File,
@@ -825,7 +951,7 @@ func handleReferences(params ReferenceParams) []Location {
 	}
 
 	// 2. References from Node Targets (Direct References)
-	tree.Walk(func(node *index.ProjectNode) {
+	Tree.Walk(func(node *index.ProjectNode) {
 		if node.Target == canonical {
 			for _, frag := range node.Fragments {
 				if frag.IsObject {
@@ -879,9 +1005,9 @@ func formatNodeInfo(node *index.ProjectNode) string {
 
 	// Find references
 	var refs []string
-	for _, ref := range tree.References {
+	for _, ref := range Tree.References {
 		if ref.Target == node {
-			container := tree.GetNodeContaining(ref.File, ref.Position)
+			container := Tree.GetNodeContaining(ref.File, ref.Position)
 			if container != nil {
 				threadName := ""
 				stateName := ""

internal/parser/parser.go

@@ -11,6 +11,7 @@ type Parser struct {
 	buf      []Token
 	comments []Comment
 	pragmas  []Pragma
+	errors   []error
 }
 
 func NewParser(input string) *Parser {
@@ -19,6 +20,10 @@ func NewParser(input string) *Parser {
 	}
 }
 
+func (p *Parser) addError(pos Position, msg string) {
+	p.errors = append(p.errors, fmt.Errorf("%d:%d: %s", pos.Line, pos.Column, msg))
+}
+
 func (p *Parser) next() Token {
 	if len(p.buf) > 0 {
 		t := p.buf[0]
@@ -71,72 +76,82 @@ func (p *Parser) Parse() (*Configuration, error) {
 			continue
 		}
 
-		def, err := p.parseDefinition()
-		if err != nil {
-			return nil, err
+		def, ok := p.parseDefinition()
+		if ok {
+			config.Definitions = append(config.Definitions, def)
+		} else {
+			// Synchronization: skip token if not consumed to make progress
+			if p.peek() == tok {
+				p.next()
+			}
 		}
-		config.Definitions = append(config.Definitions, def)
 	}
 	config.Comments = p.comments
 	config.Pragmas = p.pragmas
-	return config, nil
+
+	var err error
+	if len(p.errors) > 0 {
+		err = p.errors[0]
+	}
+	return config, err
 }
 
-func (p *Parser) parseDefinition() (Definition, error) {
+func (p *Parser) parseDefinition() (Definition, bool) {
 	tok := p.next()
 	switch tok.Type {
 	case TokenIdentifier:
-		// Could be Field = Value OR Node = { ... }
 		name := tok.Value
-		if p.next().Type != TokenEqual {
-			return nil, fmt.Errorf("%d:%d: expected =", tok.Position.Line, tok.Position.Column)
+		if p.peek().Type != TokenEqual {
+			p.addError(tok.Position, "expected =")
+			return nil, false
 		}
+		p.next() // Consume =
 
-		// Disambiguate based on RHS
 		nextTok := p.peek()
 		if nextTok.Type == TokenLBrace {
-			// Check if it looks like a Subnode (contains definitions) or Array (contains values)
 			if p.isSubnodeLookahead() {
-				sub, err := p.parseSubnode()
-				if err != nil {
-					return nil, err
+				sub, ok := p.parseSubnode()
+				if !ok {
+					return nil, false
 				}
 				return &ObjectNode{
 					Position: tok.Position,
 					Name:     name,
 					Subnode:  sub,
-				}, nil
+				}, true
 			}
 		}
 
-		// Default to Field
-		val, err := p.parseValue()
-		if err != nil {
-			return nil, err
+		val, ok := p.parseValue()
+		if !ok {
+			return nil, false
 		}
 		return &Field{
 			Position: tok.Position,
 			Name:     name,
 			Value:    val,
-		}, nil
+		}, true
 
 	case TokenObjectIdentifier:
-		// node = subnode
 		name := tok.Value
-		if p.next().Type != TokenEqual {
-			return nil, fmt.Errorf("%d:%d: expected =", tok.Position.Line, tok.Position.Column)
+		if p.peek().Type != TokenEqual {
+			p.addError(tok.Position, "expected =")
+			return nil, false
 		}
-		sub, err := p.parseSubnode()
-		if err != nil {
-			return nil, err
+		p.next() // Consume =
+
+		sub, ok := p.parseSubnode()
+		if !ok {
+			return nil, false
 		}
 		return &ObjectNode{
 			Position: tok.Position,
 			Name:     name,
 			Subnode:  sub,
-		}, nil
+		}, true
 	default:
-		return nil, fmt.Errorf("%d:%d: unexpected token %v", tok.Position.Line, tok.Position.Column, tok.Value)
+		p.addError(tok.Position, fmt.Sprintf("unexpected token %v", tok.Value))
+		return nil, false
 	}
 }
 
@@ -176,10 +191,11 @@ func (p *Parser) isSubnodeLookahead() bool {
 	return false
 }
 
-func (p *Parser) parseSubnode() (Subnode, error) {
+func (p *Parser) parseSubnode() (Subnode, bool) {
 	tok := p.next()
 	if tok.Type != TokenLBrace {
-		return Subnode{}, fmt.Errorf("%d:%d: expected {", tok.Position.Line, tok.Position.Column)
+		p.addError(tok.Position, "expected {")
+		return Subnode{}, false
 	}
 	sub := Subnode{Position: tok.Position}
 	for {
@@ -190,18 +206,23 @@ func (p *Parser) parseSubnode() (Subnode, error) {
 			break
 		}
 		if t.Type == TokenEOF {
-			return sub, fmt.Errorf("%d:%d: unexpected EOF, expected }", t.Position.Line, t.Position.Column)
+			p.addError(t.Position, "unexpected EOF, expected }")
+			sub.EndPosition = t.Position
+			return sub, true
 		}
-		def, err := p.parseDefinition()
-		if err != nil {
-			return sub, err
+		def, ok := p.parseDefinition()
+		if ok {
+			sub.Definitions = append(sub.Definitions, def)
+		} else {
+			if p.peek() == t {
+				p.next()
+			}
 		}
-		sub.Definitions = append(sub.Definitions, def)
 	}
-	return sub, nil
+	return sub, true
 }
 
-func (p *Parser) parseValue() (Value, error) {
+func (p *Parser) parseValue() (Value, bool) {
 	tok := p.next()
 	switch tok.Type {
 	case TokenString:
@@ -209,24 +230,21 @@ func (p *Parser) parseValue() (Value, error) {
 			Position: tok.Position,
 			Value:    strings.Trim(tok.Value, "\""),
 			Quoted:   true,
-		}, nil
+		}, true
 
 	case TokenNumber:
-		// Simplistic handling
 		if strings.Contains(tok.Value, ".") || strings.Contains(tok.Value, "e") {
 			f, _ := strconv.ParseFloat(tok.Value, 64)
-			return &FloatValue{Position: tok.Position, Value: f, Raw: tok.Value}, nil
+			return &FloatValue{Position: tok.Position, Value: f, Raw: tok.Value}, true
 		}
 		i, _ := strconv.ParseInt(tok.Value, 0, 64)
-		return &IntValue{Position: tok.Position, Value: i, Raw: tok.Value}, nil
+		return &IntValue{Position: tok.Position, Value: i, Raw: tok.Value}, true
 	case TokenBool:
 		return &BoolValue{Position: tok.Position, Value: tok.Value == "true"},
-			nil
+			true
 	case TokenIdentifier:
-		// reference?
-		return &ReferenceValue{Position: tok.Position, Value: tok.Value}, nil
+		return &ReferenceValue{Position: tok.Position, Value: tok.Value}, true
 	case TokenLBrace:
-		// array
 		arr := &ArrayValue{Position: tok.Position}
 		for {
 			t := p.peek()
@@ -239,14 +257,15 @@ func (p *Parser) parseValue() (Value, error) {
 				p.next()
 				continue
 			}
-			val, err := p.parseValue()
-			if err != nil {
-				return nil, err
+			val, ok := p.parseValue()
+			if !ok {
+				return nil, false
 			}
 			arr.Elements = append(arr.Elements, val)
 		}
-		return arr, nil
+		return arr, true
 	default:
-		return nil, fmt.Errorf("%d:%d: unexpected value token %v", tok.Position.Line, tok.Position.Column, tok.Value)
+		p.addError(tok.Position, fmt.Sprintf("unexpected value token %v", tok.Value))
+		return nil, false
 	}
 }

specification.md

@@ -29,7 +29,12 @@ The LSP server should provide the following capabilities:
 - **Go to Definition**: Jump to the definition of a reference, supporting navigation across any file in the current project.
 - **Go to References**: Find usages of a node or field, supporting navigation across any file in the current project.
 - **Code Completion**: Autocomplete fields, values, and references.
-- **Code Snippets**: Provide snippets for common patterns.
+  - **Context-Aware**: Suggestions depend on the cursor position (e.g., inside an object, assigning a value).
+  - **Schema-Driven**: Field suggestions are derived from the CUE schema for the current object's Class, indicating mandatory vs. optional fields.
+  - **Reference Suggestions**:
+    - `DataSource` fields suggest available DataSource objects.
+    - `Functions` (in Threads) suggest available GAM objects.
+- **Code Snippets**: Provide snippets for common patterns (e.g., `+Object = { ... }`).
 - **Formatting**: Format the document using the same rules and engine as the `fmt` command.
 
 ## Build System & File Structure
@@ -47,9 +52,9 @@ The LSP server should provide the following capabilities:
   - **Namespace Consistency**: The build tool must verify that all input files belong to the same project namespace (the first segment of the `#package` URI). If multiple project namespaces are detected, the build must fail with an error.
   - **Target**: The build output is written to a single target file (e.g., provided via CLI or API).
   - **Multi-File Definitions**: Nodes and objects can be defined across multiple files. The build tool, validator, and LSP must merge these definitions (including all fields and sub-nodes) from the entire project to create a unified view before processing or validating.
-  - **Global References**: References to nodes, signals, or objects can point to definitions located in any file within the project.
-  - **Merging Order**: For objects defined across multiple files, the **first file** to be considered is the one containing the `Class` field definition.
-  - **Field Order**: Within a single file, the relative order of defined fields must be maintained.
+  - **Global References**: References to nodes, signals, or objects can point to definitions located in any file within the project. Support for dot-separated paths (e.g., `Node.SubNode`) is required.
+  - **Merging Order**: For objects defined across multiple files, definitions are merged. The build tool must preserve the relative order of fields and sub-nodes as they appear in the source files, interleaving them correctly in the final output.
+  - **Field Order**: Within a single file (and across merged files), the relative order of defined fields must be maintained in the output.
   - The LSP indexes only files belonging to the same project/namespace scope.
 - **Output**: The output format is the same as the input configuration but without the `#package` macro.
 
@@ -160,13 +165,13 @@ The tool must build an index of the configuration to support LSP features and va
     - **Field Order**: Verification that specific fields appear in a prescribed order when required by the class definition.
     - **Conditional Fields**: Validation of fields whose presence or value depends on the values of other fields within the same node or context.
   - **Schema Definition**:
-    - Class validation rules must be defined in a separate schema file.
+    - Class validation rules must be defined in a separate schema file using the **CUE** language.
     - **Project-Specific Classes**: Developers can define their own project-specific classes and corresponding validation rules, expanding the validation capabilities for their specific needs.
   - **Schema Loading**:
-    - **Default Schema**: The tool should look for a default schema file `marte_schema.json` in standard system locations:
-      - `/usr/share/mdt/marte_schema.json`
-      - `$HOME/.local/share/mdt/marte_schema.json`
-    - **Project Schema**: If a file named `.marte_schema.json` exists in the project root, it must be loaded.
+    - **Default Schema**: The tool should look for a default schema file `marte_schema.cue` in standard system locations:
+      - `/usr/share/mdt/marte_schema.cue`
+      - `$HOME/.local/share/mdt/marte_schema.cue`
+    - **Project Schema**: If a file named `.marte_schema.cue` exists in the project root, it must be loaded.
     - **Merging**: The final schema is a merge of the built-in schema, the system default schema (if found), and the project-specific schema. Rules in later sources (Project > System > Built-in) append to or override earlier ones.
 - **Duplicate Fields**:
   - **Constraint**: A field must not be defined more than once within the same object/node scope, even if those definitions are spread across different files.

test/lsp_completion_test.go

@@ -0,0 +1,320 @@
+package integration
+
+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"
+	"github.com/marte-community/marte-dev-tools/internal/schema"
+)
+
+func TestHandleCompletion(t *testing.T) {
+	setup := func() {
+		lsp.Tree = index.NewProjectTree()
+		lsp.Documents = make(map[string]string)
+		lsp.ProjectRoot = "."
+		lsp.GlobalSchema = schema.NewSchema()
+	}
+
+	uri := "file://test.marte"
+	path := "test.marte"
+
+	t.Run("Suggest Classes", func(t *testing.T) {
+		setup()
+		content := "+Obj = { Class = "
+		lsp.Documents[uri] = content
+
+		params := lsp.CompletionParams{
+			TextDocument: lsp.TextDocumentIdentifier{URI: uri},
+			Position:     lsp.Position{Line: 0, Character: len(content)},
+		}
+
+		list := lsp.HandleCompletion(params)
+		if list == nil || len(list.Items) == 0 {
+			t.Fatal("Expected class suggestions, got none")
+		}
+
+		found := false
+		for _, item := range list.Items {
+			if item.Label == "RealTimeApplication" {
+				found = true
+				break
+			}
+		}
+		if !found {
+			t.Error("Expected RealTimeApplication in class suggestions")
+		}
+	})
+
+	t.Run("Suggest Fields", func(t *testing.T) {
+		setup()
+		content := `
++MyApp = {
+    Class = RealTimeApplication
+    
+}
+`
+		lsp.Documents[uri] = content
+		p := parser.NewParser(content)
+		cfg, _ := p.Parse()
+		lsp.Tree.AddFile(path, cfg)
+
+		// Position at line 3 (empty line inside MyApp)
+		params := lsp.CompletionParams{
+			TextDocument: lsp.TextDocumentIdentifier{URI: uri},
+			Position:     lsp.Position{Line: 3, Character: 4},
+		}
+
+		list := lsp.HandleCompletion(params)
+		if list == nil || len(list.Items) == 0 {
+			t.Fatal("Expected field suggestions, got none")
+		}
+
+		foundData := false
+		for _, item := range list.Items {
+			if item.Label == "Data" {
+				foundData = true
+				if item.Detail != "Mandatory" {
+					t.Errorf("Expected Data to be Mandatory, got %s", item.Detail)
+				}
+			}
+		}
+		if !foundData {
+			t.Error("Expected 'Data' in field suggestions for RealTimeApplication")
+		}
+	})
+
+	t.Run("Suggest References (DataSource)", func(t *testing.T) {
+		setup()
+		content := `
+$App = {
+    $Data = {
+        +InDS = {
+            Class = FileReader
+            +Signals = {
+                Sig1 = { Type = uint32 }
+            }
+        }
+    }
+}
++MyGAM = {
+    Class = IOGAM
+    +InputSignals = {
+        S1 = { DataSource =  }
+    }
+}
+`
+		lsp.Documents[uri] = content
+		p := parser.NewParser(content)
+		cfg, _ := p.Parse()
+		lsp.Tree.AddFile(path, cfg)
+		lsp.Tree.ResolveReferences()
+
+		// Position at end of "DataSource = "
+		params := lsp.CompletionParams{
+			TextDocument: lsp.TextDocumentIdentifier{URI: uri},
+			Position:     lsp.Position{Line: 14, Character: 28},
+		}
+
+		list := lsp.HandleCompletion(params)
+		if list == nil || len(list.Items) == 0 {
+			t.Fatal("Expected DataSource suggestions, got none")
+		}
+
+		foundDS := false
+		for _, item := range list.Items {
+			if item.Label == "InDS" {
+				foundDS = true
+				break
+			}
+		}
+		if !foundDS {
+			t.Error("Expected 'InDS' in suggestions for DataSource field")
+		}
+	})
+
+	t.Run("Filter Existing Fields", func(t *testing.T) {
+		setup()
+		content := `
++MyThread = {
+    Class = RealTimeThread
+    Functions = { }
+    
+}
+`
+		lsp.Documents[uri] = content
+		p := parser.NewParser(content)
+		cfg, _ := p.Parse()
+		lsp.Tree.AddFile(path, cfg)
+
+		// Position at line 4
+		params := lsp.CompletionParams{
+			TextDocument: lsp.TextDocumentIdentifier{URI: uri},
+			Position:     lsp.Position{Line: 4, Character: 4},
+		}
+
+		list := lsp.HandleCompletion(params)
+		for _, item := range list.Items {
+			if item.Label == "Functions" || item.Label == "Class" {
+				t.Errorf("Did not expect already defined field %s in suggestions", item.Label)
+			}
+		}
+	})
+
+		t.Run("Scope-aware suggestions", func(t *testing.T) {
+		setup()
+		// Define a project DataSource in one file
+		cfg1, _ := parser.NewParser("#package MYPROJ.Data\n+ProjectDS = { Class = FileReader +Signals = { S1 = { Type = int32 } } }").Parse()
+		lsp.Tree.AddFile("project_ds.marte", cfg1)
+
+		// Define an isolated file
+		contentIso := "+MyGAM = { Class = IOGAM +InputSignals = { S1 = { DataSource =  } } }"
+		lsp.Documents["file://iso.marte"] = contentIso
+		cfg2, _ := parser.NewParser(contentIso).Parse()
+		lsp.Tree.AddFile("iso.marte", cfg2)
+
+		lsp.Tree.ResolveReferences()
+
+		// Completion in isolated file
+		params := lsp.CompletionParams{
+			TextDocument: lsp.TextDocumentIdentifier{URI: "file://iso.marte"},
+			Position:     lsp.Position{Line: 0, Character: strings.Index(contentIso, "DataSource = ") + len("DataSource = ") + 1},
+		}
+
+		list := lsp.HandleCompletion(params)
+		foundProjectDS := false
+		if list != nil {
+			for _, item := range list.Items {
+				if item.Label == "ProjectDS" {
+					foundProjectDS = true
+					break
+				}
+			}
+		}
+		if foundProjectDS {
+			t.Error("Did not expect ProjectDS in isolated file suggestions")
+		}
+
+		// Completion in a project file
+		lineContent := "+MyGAM = { Class = IOGAM +InputSignals = { S1 = { DataSource = Dummy } } }"
+		contentPrj := "#package MYPROJ.App\n" + lineContent
+		lsp.Documents["file://prj.marte"] = contentPrj
+		pPrj := parser.NewParser(contentPrj)
+		cfg3, err := pPrj.Parse()
+		if err != nil {
+			t.Logf("Parser error in contentPrj: %v", err)
+		}
+		lsp.Tree.AddFile("prj.marte", cfg3)
+		lsp.Tree.ResolveReferences()
+
+		paramsPrj := lsp.CompletionParams{
+			TextDocument: lsp.TextDocumentIdentifier{URI: "file://prj.marte"},
+			Position:     lsp.Position{Line: 1, Character: strings.Index(lineContent, "Dummy")},
+		}
+
+		listPrj := lsp.HandleCompletion(paramsPrj)
+		foundProjectDS = false
+		if listPrj != nil {
+			for _, item := range listPrj.Items {
+				if item.Label == "ProjectDS" {
+					foundProjectDS = true
+					break
+				}
+			}
+		}
+		if !foundProjectDS {
+			t.Error("Expected ProjectDS in project file suggestions")
+		}
+	})
+
+	t.Run("Suggest Signal Types", func(t *testing.T) {
+		setup()
+		content := `
++DS = {
+    Class = FileReader
+    Signals = {
+        S1 = { Type =  }
+    }
+}
+`
+		lsp.Documents[uri] = content
+		p := parser.NewParser(content)
+		cfg, _ := p.Parse()
+		lsp.Tree.AddFile(path, cfg)
+
+		params := lsp.CompletionParams{
+			TextDocument: lsp.TextDocumentIdentifier{URI: uri},
+			Position:     lsp.Position{Line: 4, Character: strings.Index(content, "Type = ") + len("Type = ") + 1},
+		}
+
+		list := lsp.HandleCompletion(params)
+		if list == nil {
+			t.Fatal("Expected signal type suggestions")
+		}
+
+		foundUint32 := false
+		for _, item := range list.Items {
+			if item.Label == "uint32" {
+				foundUint32 = true
+				break
+			}
+		}
+		if !foundUint32 {
+			t.Error("Expected uint32 in suggestions")
+		}
+	})
+
+	t.Run("Suggest CUE Enums", func(t *testing.T) {
+		setup()
+		// Inject custom schema with enum
+		custom := []byte(`
+package schema
+#Classes: {
+    TestEnumClass: {
+        Mode: "Auto" | "Manual"
+    }
+}
+`)
+		val := lsp.GlobalSchema.Context.CompileBytes(custom)
+		lsp.GlobalSchema.Value = lsp.GlobalSchema.Value.Unify(val)
+
+		content := `
++Obj = {
+    Class = TestEnumClass
+    Mode =  
+}
+`
+		lsp.Documents[uri] = content
+		p := parser.NewParser(content)
+		cfg, _ := p.Parse()
+		lsp.Tree.AddFile(path, cfg)
+
+		params := lsp.CompletionParams{
+			TextDocument: lsp.TextDocumentIdentifier{URI: uri},
+			Position:     lsp.Position{Line: 3, Character: strings.Index(content, "Mode = ") + len("Mode = ") + 1},
+		}
+
+		list := lsp.HandleCompletion(params)
+		if list == nil {
+			t.Fatal("Expected enum suggestions")
+		}
+
+		foundAuto := false
+		for _, item := range list.Items {
+			if item.Label == "\"Auto\"" { // CUE string value includes quotes
+				foundAuto = true
+				break
+			}
+		}
+		if !foundAuto {
+			// Check if it returned without quotes?
+			// v.String() returns quoted for string.
+			t.Error("Expected \"Auto\" in suggestions")
+			for _, item := range list.Items {
+				t.Logf("Suggestion: %s", item.Label)
+			}
+		}
+	})
+}

test/lsp_server_test.go

@@ -1,4 +1,4 @@
-package lsp
+package integration
 
 import (
 	"encoding/json"
@@ -8,6 +8,7 @@ import (
 	"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"
 )
 
@@ -24,50 +25,38 @@ func TestInitProjectScan(t *testing.T) {
 		t.Fatal(err)
 	}
 	// File 2: Reference
-	// +Source = { Class = C Link = Target }
-	// Link = Target starts at index ...
-	// #package Test.Common (21 chars including newline)
-	// +Source = { Class = C Link = Target }
-	// 012345678901234567890123456789012345
-	// Previous offset was 29.
-	// Now add 21?
-	// #package Test.Common\n
-	// +Source = ...
-	// So add 21 to Character? Or Line 1?
-	// It's on Line 1 (0-based 1).
 	if err := os.WriteFile(filepath.Join(tmpDir, "ref.marte"), []byte("#package Test.Common\n+Source = { Class = C Link = Target }"), 0644); err != nil {
 		t.Fatal(err)
 	}
 
 	// 2. Initialize
-	tree = index.NewProjectTree() // Reset global tree
+	lsp.Tree = index.NewProjectTree() // Reset global tree
 
-	initParams := InitializeParams{RootPath: tmpDir}
+	initParams := lsp.InitializeParams{RootPath: tmpDir}
 	paramsBytes, _ := json.Marshal(initParams)
 
-	msg := &JsonRpcMessage{
+	msg := &lsp.JsonRpcMessage{
 		Method: "initialize",
 		Params: paramsBytes,
 		ID:     1,
 	}
 
-	handleMessage(msg)
+	lsp.HandleMessage(msg)
 
 	// Query the reference in ref.marte at "Target"
-	// Target starts at index 29 (0-based) on Line 1
-	defParams := DefinitionParams{
-		TextDocument: TextDocumentIdentifier{URI: "file://" + filepath.Join(tmpDir, "ref.marte")},
-		Position:     Position{Line: 1, Character: 29},
+	defParams := lsp.DefinitionParams{
+		TextDocument: lsp.TextDocumentIdentifier{URI: "file://" + filepath.Join(tmpDir, "ref.marte")},
+		Position:     lsp.Position{Line: 1, Character: 29},
 	}
 
-	res := handleDefinition(defParams)
+	res := lsp.HandleDefinition(defParams)
 	if res == nil {
 		t.Fatal("Definition not found via LSP after initialization")
 	}
 
-	locs, ok := res.([]Location)
+	locs, ok := res.([]lsp.Location)
 	if !ok {
-		t.Fatalf("Expected []Location, got %T", res)
+		t.Fatalf("Expected []lsp.Location, got %T", res)
 	}
 
 	if len(locs) == 0 {
@@ -83,7 +72,7 @@ func TestInitProjectScan(t *testing.T) {
 
 func TestHandleDefinition(t *testing.T) {
 	// Reset tree for test
-	tree = index.NewProjectTree()
+	lsp.Tree = index.NewProjectTree()
 
 	content := `
 +MyObject = {
@@ -100,28 +89,28 @@ func TestHandleDefinition(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Parse failed: %v", err)
 	}
-	tree.AddFile(path, config)
-	tree.ResolveReferences()
+	lsp.Tree.AddFile(path, config)
+	lsp.Tree.ResolveReferences()
 
-	t.Logf("Refs: %d", len(tree.References))
-	for _, r := range tree.References {
+	t.Logf("Refs: %d", len(lsp.Tree.References))
+	for _, r := range lsp.Tree.References {
 		t.Logf("  %s at %d:%d", r.Name, r.Position.Line, r.Position.Column)
 	}
 
 	// Test Go to Definition on MyObject reference
-	params := DefinitionParams{
-		TextDocument: TextDocumentIdentifier{URI: "file://" + path},
-		Position:     Position{Line: 6, Character: 15}, // "MyObject" in RefField = MyObject
+	params := lsp.DefinitionParams{
+		TextDocument: lsp.TextDocumentIdentifier{URI: "file://" + path},
+		Position:     lsp.Position{Line: 6, Character: 15}, // "MyObject" in RefField = MyObject
 	}
 
-	result := handleDefinition(params)
+	result := lsp.HandleDefinition(params)
 	if result == nil {
-		t.Fatal("handleDefinition returned nil")
+		t.Fatal("HandleDefinition returned nil")
 	}
 
-	locations, ok := result.([]Location)
+	locations, ok := result.([]lsp.Location)
 	if !ok {
-		t.Fatalf("Expected []Location, got %T", result)
+		t.Fatalf("Expected []lsp.Location, got %T", result)
 	}
 
 	if len(locations) != 1 {
@@ -135,7 +124,7 @@ func TestHandleDefinition(t *testing.T) {
 
 func TestHandleReferences(t *testing.T) {
 	// Reset tree for test
-	tree = index.NewProjectTree()
+	lsp.Tree = index.NewProjectTree()
 
 	content := `
 +MyObject = {
@@ -155,17 +144,17 @@ func TestHandleReferences(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Parse failed: %v", err)
 	}
-	tree.AddFile(path, config)
-	tree.ResolveReferences()
+	lsp.Tree.AddFile(path, config)
+	lsp.Tree.ResolveReferences()
 
 	// Test Find References for MyObject (triggered from its definition)
-	params := ReferenceParams{
-		TextDocument: TextDocumentIdentifier{URI: "file://" + path},
-		Position:     Position{Line: 1, Character: 1}, // "+MyObject"
-		Context:      ReferenceContext{IncludeDeclaration: true},
+	params := lsp.ReferenceParams{
+		TextDocument: lsp.TextDocumentIdentifier{URI: "file://" + path},
+		Position:     lsp.Position{Line: 1, Character: 1}, // "+MyObject"
+		Context:      lsp.ReferenceContext{IncludeDeclaration: true},
 	}
 
-	locations := handleReferences(params)
+	locations := lsp.HandleReferences(params)
 	if len(locations) != 3 { // 1 declaration + 2 references
 		t.Fatalf("Expected 3 locations, got %d", len(locations))
 	}
@@ -181,15 +170,15 @@ Field=1
 `
 	uri := "file:///test.marte"
 
-	// Open (populate documents map)
-	documents[uri] = content
+	// Open (populate Documents map)
+	lsp.Documents[uri] = content
 
 	// Format
-	params := DocumentFormattingParams{
-		TextDocument: TextDocumentIdentifier{URI: uri},
+	params := lsp.DocumentFormattingParams{
+		TextDocument: lsp.TextDocumentIdentifier{URI: uri},
 	}
 
-	edits := handleFormatting(params)
+	edits := lsp.HandleFormatting(params)
 
 	if len(edits) != 1 {
 		t.Fatalf("Expected 1 edit, got %d", len(edits))

test/parser_strictness_test.go

@@ -1,4 +1,4 @@
-package parser_test
+package integration
 
 import (
 	"testing"

test/parser_test.go

@@ -1,7 +1,9 @@
-package parser
+package integration
 
 import (
 	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/parser"
 )
 
 func TestParseBasic(t *testing.T) {
@@ -22,7 +24,7 @@ $Node2 = {
     Array = {1 2 3}
 }
 `
-	p := NewParser(input)
+	p := parser.NewParser(input)
 	config, err := p.Parse()
 	if err != nil {
 		t.Fatalf("Parse error: %v", err)

test/validator_gam_direction_test.go

@@ -0,0 +1,85 @@
+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/validator"
+)
+
+func TestGAMSignalDirectionality(t *testing.T) {
+	content := `
+$App = {
+    $Data = {
+        +InDS = { Class = FileReader Filename="f" +Signals = { S1 = { Type = uint32 } } }
+        +OutDS = { Class = FileWriter Filename="f" +Signals = { S1 = { Type = uint32 } } }
+        +InOutDS = { Class = FileDataSource Filename="f" +Signals = { S1 = { Type = uint32 } } }
+    }
+    +ValidGAM = {
+        Class = IOGAM
+        InputSignals = {
+            S1 = { DataSource = InDS }
+            S2 = { DataSource = InOutDS Alias = S1 }
+        }
+        OutputSignals = {
+            S3 = { DataSource = OutDS Alias = S1 }
+            S4 = { DataSource = InOutDS Alias = S1 }
+        }
+    }
+    +InvalidGAM = {
+        Class = IOGAM
+        InputSignals = {
+            BadIn = { DataSource = OutDS Alias = S1 }
+        }
+        OutputSignals = {
+            BadOut = { DataSource = InDS Alias = S1 }
+        }
+    }
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("dir.marte", config)
+	idx.ResolveReferences()
+
+	v := validator.NewValidator(idx, ".")
+	v.ValidateProject()
+
+	// Check ValidGAM has NO directionality errors
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "is Output-only but referenced in InputSignals") ||
+			strings.Contains(d.Message, "is Input-only but referenced in OutputSignals") {
+			if strings.Contains(d.Message, "ValidGAM") {
+				t.Errorf("Unexpected direction error for ValidGAM: %s", d.Message)
+			}
+		}
+	}
+
+	// Check InvalidGAM HAS errors
+	foundBadIn := false
+	foundBadOut := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "InvalidGAM") {
+			if strings.Contains(d.Message, "is Output-only but referenced in InputSignals") {
+				foundBadIn = true
+			}
+			if strings.Contains(d.Message, "is Input-only but referenced in OutputSignals") {
+				foundBadOut = true
+			}
+		}
+	}
+
+	if !foundBadIn {
+		t.Error("Expected error for OutDS in InputSignals of InvalidGAM")
+	}
+	if !foundBadOut {
+		t.Error("Expected error for InDS in OutputSignals of InvalidGAM")
+	}
+}