Added schema validation and schema db

internal/schema/marte.json

@@ -0,0 +1,156 @@
+{
+  "classes": {
+    "RealTimeApplication": {
+      "fields": [
+        {"name": "Functions", "type": "node", "mandatory": true},
+        {"name": "Data", "type": "node", "mandatory": true},
+        {"name": "States", "type": "node", "mandatory": true}
+      ]
+    },
+    "StateMachine": {
+      "fields": [
+        {"name": "States", "type": "node", "mandatory": true}
+      ]
+    },
+    "GAMScheduler": {
+      "fields": [
+        {"name": "TimingDataSource", "type": "reference", "mandatory": true}
+      ]
+    },
+    "TimingDataSource": {
+      "fields": []
+    },
+    "IOGAM": {
+      "fields": [
+        {"name": "InputSignals", "type": "node", "mandatory": false},
+        {"name": "OutputSignals", "type": "node", "mandatory": false}
+      ]
+    },
+    "ReferenceContainer": {
+      "fields": []
+    },
+    "ConstantGAM": {
+      "fields": []
+    },
+    "PIDGAM": {
+      "fields": [
+        {"name": "Kp", "type": "float", "mandatory": true},
+        {"name": "Ki", "type": "float", "mandatory": true},
+        {"name": "Kd", "type": "float", "mandatory": true}
+      ]
+    },
+    "FileDataSource": {
+      "fields": [
+        {"name": "Filename", "type": "string", "mandatory": true},
+        {"name": "Format", "type": "string", "mandatory": false}
+      ]
+    },
+    "LoggerDataSource": {
+      "fields": []
+    },
+    "DANStream": {
+      "fields": [
+        {"name": "Timeout", "type": "int", "mandatory": false}
+      ]
+    },
+    "EPICSCAInput": {
+      "fields": []
+    },
+    "EPICSCAOutput": {
+      "fields": []
+    },
+    "EPICSPVAInput": {
+      "fields": []
+    },
+    "EPICSPVAOutput": {
+      "fields": []
+    },
+    "SDNSubscriber": {
+      "fields": [
+        {"name": "Address", "type": "string", "mandatory": true},
+        {"name": "Port", "type": "int", "mandatory": true},
+        {"name": "Interface", "type": "string", "mandatory": false}
+      ]
+    },
+    "SDNPublisher": {
+      "fields": [
+        {"name": "Address", "type": "string", "mandatory": true},
+        {"name": "Port", "type": "int", "mandatory": true},
+        {"name": "Interface", "type": "string", "mandatory": false}
+      ]
+    },
+    "UDPReceiver": {
+      "fields": [
+        {"name": "Port", "type": "int", "mandatory": true},
+        {"name": "Address", "type": "string", "mandatory": false}
+      ]
+    },
+    "UDPSender": {
+      "fields": [
+        {"name": "Destination", "type": "string", "mandatory": true}
+      ]
+    },
+    "FileReader": {
+      "fields": [
+        {"name": "Filename", "type": "string", "mandatory": true},
+        {"name": "Format", "type": "string", "mandatory": false},
+        {"name": "Interpolate", "type": "string", "mandatory": false}
+      ]
+    },
+    "FileWriter": {
+      "fields": [
+        {"name": "Filename", "type": "string", "mandatory": true},
+        {"name": "Format", "type": "string", "mandatory": false},
+        {"name": "StoreOnTrigger", "type": "int", "mandatory": false}
+      ]
+    },
+    "OrderedClass": {
+      "ordered": true,
+      "fields": [
+        {"name": "First", "type": "int", "mandatory": true},
+        {"name": "Second", "type": "string", "mandatory": true}
+      ]
+    },
+    "BaseLib2GAM": { "fields": [] },
+    "ConversionGAM": { "fields": [] },
+    "DoubleHandshakeGAM": { "fields": [] },
+    "FilterGAM": { "fields": [] },
+    "HistogramGAM": { "fields": [] },
+    "Interleaved2FlatGAM": { "fields": [] },
+    "FlattenedStructIOGAM": { "fields": [] },
+    "MathExpressionGAM": { "fields": [] },
+    "MessageGAM": { "fields": [] },
+    "MuxGAM": { "fields": [] },
+    "SimulinkWrapperGAM": { "fields": [] },
+    "SSMGAM": { "fields": [] },
+    "StatisticsGAM": { "fields": [] },
+    "TimeCorrectionGAM": { "fields": [] },
+    "TriggeredIOGAM": { "fields": [] },
+    "WaveformGAM": { "fields": [] },
+    "DAN": { "fields": [] },
+    "LinuxTimer": { "fields": [] },
+    "LinkDataSource": { "fields": [] },
+    "MDSReader": { "fields": [] },
+    "MDSWriter": { "fields": [] },
+    "NI1588TimeStamp": { "fields": [] },
+    "NI6259ADC": { "fields": [] },
+    "NI6259DAC": { "fields": [] },
+    "NI6259DIO": { "fields": [] },
+    "NI6368ADC": { "fields": [] },
+    "NI6368DAC": { "fields": [] },
+    "NI6368DIO": { "fields": [] },
+    "NI9157CircularFifoReader": { "fields": [] },
+    "NI9157MxiDataSource": { "fields": [] },
+    "OPCUADSInput": { "fields": [] },
+    "OPCUADSOutput": { "fields": [] },
+    "RealTimeThreadAsyncBridge": { "fields": [] },
+    "RealTimeThreadSynchronisation": { "fields": [] },
+    "UARTDataSource": { "fields": [] },
+    "BaseLib2Wrapper": { "fields": [] },
+    "EPICSCAClient": { "fields": [] },
+    "EPICSPVA": { "fields": [] },
+    "MemoryGate": { "fields": [] },
+    "OPCUA": { "fields": [] },
+    "SysLogger": { "fields": [] }
+  }
+}

internal/schema/schema.go

@@ -0,0 +1,55 @@
+package schema
+
+import (
+	_ "embed"
+	"encoding/json"
+	"fmt"
+	"os"
+)
+
+//go:embed marte.json
+var defaultSchemaJSON []byte
+
+type Schema struct {
+	Classes map[string]ClassDefinition `json:"classes"`
+}
+
+type ClassDefinition struct {
+	Fields  []FieldDefinition `json:"fields"`
+	Ordered bool              `json:"ordered"`
+}
+
+type FieldDefinition struct {
+	Name      string `json:"name"`
+	Type      string `json:"type"` // "int", "float", "string", "bool", "reference", "array", "node", "any"
+	Mandatory bool   `json:"mandatory"`
+}
+
+func NewSchema() *Schema {
+	return &Schema{
+		Classes: make(map[string]ClassDefinition),
+	}
+}
+
+func LoadSchema(path string) (*Schema, error) {
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var s Schema
+	if err := json.Unmarshal(content, &s); err != nil {
+		return nil, fmt.Errorf("failed to parse schema: %v", err)
+	}
+
+	return &s, nil
+}
+
+// DefaultSchema returns a built-in schema with core MARTe classes
+func DefaultSchema() *Schema {
+	var s Schema
+	if err := json.Unmarshal(defaultSchemaJSON, &s); err != nil {
+		panic(fmt.Sprintf("failed to parse default embedded schema: %v", err))
+	}
+	return &s
+}

internal/validator/validator.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"github.com/marte-dev/marte-dev-tools/internal/index"
 	"github.com/marte-dev/marte-dev-tools/internal/parser"
+	"github.com/marte-dev/marte-dev-tools/internal/schema"
 )
 
 type DiagnosticLevel int
@@ -23,69 +24,79 @@ type Diagnostic struct {
 type Validator struct {
 	Diagnostics []Diagnostic
 	Tree        *index.ProjectTree
+	Schema      *schema.Schema
 }
 
 func NewValidator(tree *index.ProjectTree) *Validator {
-	return &Validator{Tree: tree}
+	return &Validator{
+		Tree:   tree,
+		Schema: schema.DefaultSchema(),
+	}
 }
 
 func (v *Validator) ValidateProject() {
-	if v.Tree == nil || v.Tree.Root == nil {
+	if v.Tree == nil {
 		return
 	}
+	if v.Tree.Root != nil {
 		v.validateNode(v.Tree.Root)
+	}
+	for _, node := range v.Tree.IsolatedFiles {
+		v.validateNode(node)
+	}
 }
 
 func (v *Validator) validateNode(node *index.ProjectNode) {
-	// Check for duplicate fields in this node
-	fields := make(map[string]string) // FieldName -> File
+	// Collect fields and their definitions
+	fields := make(map[string][]*parser.Field)
+	fieldOrder := []string{} // Keep track of order of appearance (approximate across fragments)
 
 	for _, frag := range node.Fragments {
 		for _, def := range frag.Definitions {
 			if f, ok := def.(*parser.Field); ok {
-				if existingFile, exists := fields[f.Name]; exists {
-					// Duplicate field
+				if _, exists := fields[f.Name]; !exists {
+					fieldOrder = append(fieldOrder, f.Name)
+				}
+				fields[f.Name] = append(fields[f.Name], f)
+			}
+		}
+	}
+
+	// 1. Check for duplicate fields
+	for name, defs := range fields {
+		if len(defs) > 1 {
+			// Report error on the second definition
+			firstFile := v.getFileForField(defs[0], node)
 			v.Diagnostics = append(v.Diagnostics, Diagnostic{
 				Level:    LevelError,
-						Message:  fmt.Sprintf("Duplicate Field Definition: '%s' is already defined in %s", f.Name, existingFile),
-						Position: f.Position,
-						File:     frag.File,
+				Message:  fmt.Sprintf("Duplicate Field Definition: '%s' is already defined in %s", name, firstFile),
+				Position: defs[1].Position,
+				File:     v.getFileForField(defs[1], node),
 			})
-				} else {
-					fields[f.Name] = frag.File
-				}
-			}
 		}
 	}
 
-	// Check for mandatory Class if it's an object node (+/$)
+	// 2. Check for mandatory Class if it's an object node (+/$)
+	className := ""
 	if node.RealName != "" && (node.RealName[0] == '+' || node.RealName[0] == '$') {
-		hasClass := false
-		hasType := false
-		for _, frag := range node.Fragments {
-			for _, def := range frag.Definitions {
-				if f, ok := def.(*parser.Field); ok {
-					if f.Name == "Class" {
-						hasClass = true
+		if classFields, ok := fields["Class"]; ok && len(classFields) > 0 {
+			// Extract class name from value
+			switch val := classFields[0].Value.(type) {
+			case *parser.StringValue:
+				className = val.Value
+			case *parser.ReferenceValue:
+				className = val.Value
 			}
-					if f.Name == "Type" {
+		}
+
+		hasType := false
+		if _, ok := fields["Type"]; ok {
 			hasType = true
 		}
-				}
-			}
-			if hasClass {
-				break
-			}
-		}
 
-		if !hasClass && !hasType {
-			// Report error on the first fragment's position
-			pos := parser.Position{Line: 1, Column: 1}
-			file := ""
-			if len(node.Fragments) > 0 {
-				pos = node.Fragments[0].ObjectPos
-				file = node.Fragments[0].File
-			}
+		if className == "" && !hasType {
+			pos := v.getNodePosition(node)
+			file := v.getNodeFile(node)
 			v.Diagnostics = append(v.Diagnostics, Diagnostic{
 				Level:    LevelError,
 				Message:  fmt.Sprintf("Node %s is an object and must contain a 'Class' field (or be a Signal with 'Type')", node.RealName),
@@ -95,12 +106,140 @@ func (v *Validator) validateNode(node *index.ProjectNode) {
 		}
 	}
 
+	// 3. Schema Validation
+	if className != "" && v.Schema != nil {
+		if classDef, ok := v.Schema.Classes[className]; ok {
+			v.validateClass(node, classDef, fields, fieldOrder)
+		}
+	}
+
 	// Recursively validate children
 	for _, child := range node.Children {
 		v.validateNode(child)
 	}
 }
 
+func (v *Validator) validateClass(node *index.ProjectNode, classDef schema.ClassDefinition, fields map[string][]*parser.Field, fieldOrder []string) {
+	// Check Mandatory Fields
+	for _, fieldDef := range classDef.Fields {
+		if fieldDef.Mandatory {
+			found := false
+			if _, ok := fields[fieldDef.Name]; ok {
+				found = true
+			} else if fieldDef.Type == "node" {
+				// Check children for nodes
+				if _, ok := node.Children[fieldDef.Name]; ok {
+					found = true
+				}
+			}
+
+			if !found {
+				v.Diagnostics = append(v.Diagnostics, Diagnostic{
+					Level:    LevelError,
+					Message:  fmt.Sprintf("Missing mandatory field '%s' for class '%s'", fieldDef.Name, node.Metadata["Class"]),
+					Position: v.getNodePosition(node),
+					File:     v.getNodeFile(node),
+				})
+			}
+		}
+	}
+
+	// Check Field Types
+	for _, fieldDef := range classDef.Fields {
+		if fList, ok := fields[fieldDef.Name]; ok {
+			f := fList[0] // Check the first definition (duplicates handled elsewhere)
+			if !v.checkType(f.Value, fieldDef.Type) {
+				v.Diagnostics = append(v.Diagnostics, Diagnostic{
+					Level:    LevelError,
+					Message:  fmt.Sprintf("Field '%s' expects type '%s'", fieldDef.Name, fieldDef.Type),
+					Position: f.Position,
+					File:     v.getFileForField(f, node),
+				})
+			}
+		}
+	}
+
+	// Check Field Order
+	if classDef.Ordered {
+		// Verify that fields present in the node appear in the order defined in the schema
+		// Only consider fields that are actually in the schema's field list
+		schemaIdx := 0
+		for _, nodeFieldName := range fieldOrder {
+			// Find this field in schema
+			foundInSchema := false
+			for i, fd := range classDef.Fields {
+				if fd.Name == nodeFieldName {
+					foundInSchema = true
+					// Check if this field appears AFTER the current expected position
+					if i < schemaIdx {
+						// This field appears out of order (it should have appeared earlier, or previous fields were missing but this one came too late? No, simple relative order)
+						// Actually, simple check: `i` must be >= `lastSeenSchemaIdx`.
+						v.Diagnostics = append(v.Diagnostics, Diagnostic{
+							Level:    LevelError,
+							Message:  fmt.Sprintf("Field '%s' is out of order", nodeFieldName),
+							Position: fields[nodeFieldName][0].Position,
+							File:     v.getFileForField(fields[nodeFieldName][0], node),
+						})
+					} else {
+						schemaIdx = i
+					}
+					break
+				}
+			}
+			if !foundInSchema {
+				// Ignore extra fields for order check? Spec doesn't say strict closed schema.
+			}
+		}
+	}
+}
+
+func (v *Validator) checkType(val parser.Value, expectedType string) bool {
+	switch expectedType {
+	case "int":
+		_, ok := val.(*parser.IntValue)
+		return ok
+	case "float":
+		_, ok := val.(*parser.FloatValue)
+		return ok
+	case "string":
+		_, ok := val.(*parser.StringValue)
+		return ok
+	case "bool":
+		_, ok := val.(*parser.BoolValue)
+		return ok
+	case "array":
+		_, ok := val.(*parser.ArrayValue)
+		return ok
+	case "reference":
+		_, ok := val.(*parser.ReferenceValue)
+		return ok
+	case "node":
+		// This is tricky. A field cannot really be a "node" type in the parser sense (Node = { ... } is an ObjectNode, not a Field).
+		// But if the schema says "FieldX" is type "node", maybe it means it expects a reference to a node?
+		// Or maybe it means it expects a Subnode?
+		// In MARTe, `Field = { ... }` is parsed as ArrayValue usually.
+		// If `Field = SubNode`, it's `ObjectNode`.
+		// Schema likely refers to `+SubNode = { ... }`.
+		// But `validateClass` iterates `fields`.
+		// If schema defines a "field" of type "node", it might mean it expects a child node with that name.
+		return true // skip for now
+	case "any":
+		return true
+	}
+	return true
+}
+
+func (v *Validator) getFileForField(f *parser.Field, node *index.ProjectNode) string {
+	for _, frag := range node.Fragments {
+		for _, def := range frag.Definitions {
+			if def == f {
+				return frag.File
+			}
+		}
+	}
+	return ""
+}
+
 func (v *Validator) CheckUnused() {
 	referencedNodes := make(map[*index.ProjectNode]bool)
 	for _, ref := range v.Tree.References {
@@ -109,7 +248,12 @@ func (v *Validator) CheckUnused() {
 		}
 	}
 
+	if v.Tree.Root != nil {
 		v.checkUnusedRecursive(v.Tree.Root, referencedNodes)
+	}
+	for _, node := range v.Tree.IsolatedFiles {
+		v.checkUnusedRecursive(node, referencedNodes)
+	}
 }
 
 func (v *Validator) checkUnusedRecursive(node *index.ProjectNode, referenced map[*index.ProjectNode]bool) {

test/builder_multifile_test.go

@@ -1,7 +1,6 @@
 package integration
 
 import (
-	"io/ioutil"
 	"os"
 	"strings"
 	"testing"
@@ -29,8 +28,8 @@ FieldA = 10
 Class = "MyClass"
 FieldB = 20
 `
-	ioutil.WriteFile("build_multi_test/f1.marte", []byte(f1Content), 0644)
-	ioutil.WriteFile("build_multi_test/f2.marte", []byte(f2Content), 0644)
+	os.WriteFile("build_multi_test/f1.marte", []byte(f1Content), 0644)
+	os.WriteFile("build_multi_test/f2.marte", []byte(f2Content), 0644)
 	
 	// Execute Build
 	b := builder.NewBuilder([]string{"build_multi_test/f1.marte", "build_multi_test/f2.marte"})
@@ -55,7 +54,7 @@ FieldB = 20
 		t.Fatalf("Expected output file not found")
 	}
 	
-	content, err := ioutil.ReadFile(outputFile)
+	content, err := os.ReadFile(outputFile)
 	if err != nil {
 		t.Fatalf("Failed to read output: %v", err)
 	}

test/integration_test.go

@@ -169,7 +169,14 @@ func TestBuildCommand(t *testing.T) {
 	// Test Merge
 	files := []string{"integration/build_merge_1.marte", "integration/build_merge_2.marte"}
 	b := builder.NewBuilder(files)
-	err := b.Build("build_test")
+	
+	outputFile, err := os.Create("build_test/TEST.marte")
+	if err != nil {
+		t.Fatalf("Failed to create output file: %v", err)
+	}
+	defer outputFile.Close()
+
+	err = b.Build(outputFile)
 	if err != nil {
 		t.Fatalf("Build failed: %v", err)
 	}
@@ -189,12 +196,19 @@ func TestBuildCommand(t *testing.T) {
 	// Test Order (Class First)
 	filesOrder := []string{"integration/build_order_1.marte", "integration/build_order_2.marte"}
 	bOrder := builder.NewBuilder(filesOrder)
-	err = bOrder.Build("build_test")
+	
+	outputFileOrder, err := os.Create("build_test/ORDER.marte")
+	if err != nil {
+		t.Fatalf("Failed to create output file: %v", err)
+	}
+	defer outputFileOrder.Close()
+
+	err = bOrder.Build(outputFileOrder)
 	if err != nil {
 		t.Fatalf("Build order test failed: %v", err)
 	}
 	
-	contentOrder, _ := ioutil.ReadFile("build_test/TEST.marte")
+	contentOrder, _ := ioutil.ReadFile("build_test/ORDER.marte")
 	outputOrder := string(contentOrder)
 	
 	// Check for Class before Field

test/validator_components_test.go

@@ -0,0 +1,85 @@
+package integration
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/marte-dev/marte-dev-tools/internal/index"
+	"github.com/marte-dev/marte-dev-tools/internal/parser"
+	"github.com/marte-dev/marte-dev-tools/internal/validator"
+)
+
+func TestPIDGAMValidation(t *testing.T) {
+	// PIDGAM requires Kp, Ki, Kd
+	content := `
++MyPID = {
+    Class = PIDGAM
+    Kp = 1.0
+    // Missing Ki
+    // Missing Kd
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("pid.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	foundKi := false
+	foundKd := false
+
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Missing mandatory field 'Ki'") {
+			foundKi = true
+		}
+		if strings.Contains(d.Message, "Missing mandatory field 'Kd'") {
+			foundKd = true
+		}
+	}
+
+	if !foundKi {
+		t.Error("Expected error for missing 'Ki' in PIDGAM")
+	}
+	if !foundKd {
+		t.Error("Expected error for missing 'Kd' in PIDGAM")
+	}
+}
+
+func TestFileDataSourceValidation(t *testing.T) {
+	// FileDataSource requires Filename
+	content := `
++MyFile = {
+    Class = FileDataSource
+    // Missing Filename
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("file.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	found := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Missing mandatory field 'Filename'") {
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		t.Error("Expected error for missing 'Filename' in FileDataSource")
+	}
+}

test/validator_db_test.go

@@ -0,0 +1,85 @@
+package integration
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/marte-dev/marte-dev-tools/internal/index"
+	"github.com/marte-dev/marte-dev-tools/internal/parser"
+	"github.com/marte-dev/marte-dev-tools/internal/validator"
+)
+
+func TestRealTimeApplicationValidation(t *testing.T) {
+	// RealTimeApplication requires Functions, Data, States
+	content := `
++App = {
+    Class = RealTimeApplication
+    +Functions = {}
+    // Missing Data
+    // Missing States
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("app.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	missingData := false
+	missingStates := false
+
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Missing mandatory field 'Data'") {
+			missingData = true
+		}
+		if strings.Contains(d.Message, "Missing mandatory field 'States'") {
+			missingStates = true
+		}
+	}
+
+	if !missingData {
+		t.Error("Expected error for missing 'Data' field in RealTimeApplication")
+	}
+	if !missingStates {
+		t.Error("Expected error for missing 'States' field in RealTimeApplication")
+	}
+}
+
+func TestGAMSchedulerValidation(t *testing.T) {
+	// GAMScheduler requires TimingDataSource (reference)
+	content := `
++Scheduler = {
+    Class = GAMScheduler
+    // Missing TimingDataSource
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("scheduler.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	found := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Missing mandatory field 'TimingDataSource'") {
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		t.Error("Expected error for missing 'TimingDataSource' in GAMScheduler")
+	}
+}

test/validator_extra_test.go

@@ -0,0 +1,77 @@
+package integration
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/marte-dev/marte-dev-tools/internal/index"
+	"github.com/marte-dev/marte-dev-tools/internal/parser"
+	"github.com/marte-dev/marte-dev-tools/internal/validator"
+)
+
+func TestSDNSubscriberValidation(t *testing.T) {
+	// SDNSubscriber requires Address and Port
+	content := `
++MySDN = {
+    Class = SDNSubscriber
+    Address = "239.0.0.1"
+    // Missing Port
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("sdn.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	found := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Missing mandatory field 'Port'") {
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		t.Error("Expected error for missing 'Port' in SDNSubscriber")
+	}
+}
+
+func TestFileWriterValidation(t *testing.T) {
+	// FileWriter requires Filename
+	content := `
++MyWriter = {
+    Class = FileWriter
+    // Missing Filename
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("writer.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	found := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Missing mandatory field 'Filename'") {
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		t.Error("Expected error for missing 'Filename' in FileWriter")
+	}
+}

test/validator_schema_test.go

@@ -0,0 +1,138 @@
+package integration
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/marte-dev/marte-dev-tools/internal/index"
+	"github.com/marte-dev/marte-dev-tools/internal/parser"
+	"github.com/marte-dev/marte-dev-tools/internal/validator"
+)
+
+func TestSchemaValidationMandatory(t *testing.T) {
+	// StateMachine requires "States"
+	content := `
++MySM = {
+    Class = StateMachine
+    // Missing States
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("test.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	found := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Missing mandatory field 'States'") {
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		t.Error("Expected error for missing mandatory field 'States', but found none")
+	}
+}
+
+func TestSchemaValidationType(t *testing.T) {
+	// OrderedClass: First (int), Second (string)
+	content := `
++Obj = {
+    Class = OrderedClass
+    First = "WrongType" 
+    Second = "Correct"
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("test.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	found := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Field 'First' expects type 'int'") {
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		t.Error("Expected error for wrong type in field 'First', but found none")
+	}
+}
+
+func TestSchemaValidationOrder(t *testing.T) {
+	// OrderedClass: First, Second (ordered=true)
+	content := `
++Obj = {
+    Class = OrderedClass
+    Second = "Correct"
+    First = 1
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("test.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	found := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Field 'First' is out of order") {
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		t.Error("Expected error for out-of-order fields, but found none")
+	}
+}
+
+func TestSchemaValidationMandatoryNode(t *testing.T) {
+	// StateMachine requires "States" which is usually a node (+States or $States)
+	content := `
++MySM = {
+    Class = StateMachine
+    +States = {}
+}
+`
+	p := parser.NewParser(content)
+	config, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	idx := index.NewProjectTree()
+	idx.AddFile("test.marte", config)
+
+	v := validator.NewValidator(idx)
+	v.ValidateProject()
+
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "Missing mandatory field 'States'") {
+			t.Error("Reported missing mandatory field 'States' despite +States being present as a child node")
+		}
+	}
+}