fix: support log node expressions and harden microflow describe roundtrip

CHANGELOG.md

@@ -13,6 +13,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 - **Path normalization** — Relative paths in `MetadataUrl` are automatically converted to absolute `file://` URLs for Studio Pro compatibility
 - **ServiceUrl validation** — `ServiceUrl` parameter must now be a constant reference (e.g., `@Module.ConstantName`) to enforce Mendix best practice
 - **Shared URL utilities** — `internal/pathutil` package with `NormalizeURL()`, `URIToPath()`, and `PathFromURL()` for reuse across components
+
+### Changed
+
+- **MDL string literal escapes** — `mdlQuote`/`unquoteString` now treat `\n`, `\r`, `\t`, and `\\` inside single-quoted literals as escape sequences (previously a literal backslash followed by the letter). This is a compatibility break for any MDL script that intentionally embedded a raw `\n` / `\t` / `\\` as two characters; such scripts must now double the backslash (`\\n` to preserve the two-character form). Applies to `LOG` messages, `@caption`/`@annotation` text, and other string literals round-tripped via the describer.
+
 ## [0.7.0] - 2026-04-21
 
 ### Added

mdl-examples/bug-tests/264-log-node-expression-roundtrip.mdl

@@ -0,0 +1,46 @@
+-- ============================================================================
+-- Bug #264: Log node expressions and microflow describe roundtrip
+-- ============================================================================
+--
+-- Three related regressions surfaced together while exercising real .mpr files:
+--
+-- 1. Legacy `NewCaseValue` on sequence flows (Mx 9) was being dropped by the
+--    parser, so re-describing a Mx 9 project silently lost decision labels.
+-- 2. The describer bailed or emitted malformed MDL when it hit partially
+--    understood activity shapes — a single unknown subfield broke the entire
+--    microflow roundtrip.
+-- 3. The MDL grammar didn't accept the `log` activity's expression-typed NODE
+--    parameter, so any microflow containing a log node with a variable or
+--    constant reference failed to re-parse after describe.
+--
+-- Usage:
+--   mxcli exec mdl-examples/bug-tests/264-log-node-expression-roundtrip.mdl -p app.mpr
+--   Then: mxcli describe microflow BugTest264.MF_LogWithNode -p app.mpr
+--   The output must re-execute cleanly against the same project.
+-- ============================================================================
+
+create module BugTest264;
+
+-- String-literal node (backwards-compatible shape)
+create microflow BugTest264.MF_LogWithLiteralNode ()
+begin
+  log info node 'BugTest264' 'started';
+end;
+/
+
+-- Variable-ref node — exercises Node expression path
+create microflow BugTest264.MF_LogWithNode (
+  $nodeName: string
+)
+begin
+  log info node $nodeName 'hello';
+end;
+/
+
+-- Multi-line message with embedded newline — exercises the mdlQuote escape
+-- round-trip (`\n` is decoded on parse, re-encoded on describe).
+create microflow BugTest264.MF_LogMultilineMessage ()
+begin
+  log info node 'BugTest264' 'line 1\nline 2\nline 3';
+end;
+/

mdl/ast/ast_microflow.go

@@ -261,10 +261,10 @@ func (p *TemplateParam) IsDataSourceRef() bool {
 	return p.DataSourceName != ""
 }
 
-// LogStmt represents: LOG LEVEL NODE 'node' 'message' [WITH params]
+// LogStmt represents: LOG LEVEL [NODE expr] message [WITH params]
 type LogStmt struct {
 	Level       LogLevel             // Log level (INFO, WARNING, etc.)
-	Node        string               // Log node name
+	Node        Expression           // Optional log node expression
 	Message     Expression           // Message expression
 	Template    []TemplateParam      // Optional WITH template params
 	Annotations *ActivityAnnotations // Optional @position, @caption, @color, @annotation

mdl/executor/bugfix_regression_test.go

@@ -65,6 +65,157 @@ func TestFormatActivity_WhileLoop(t *testing.T) {
 	}
 }
 
+func TestAddLoopStatement_PreservesAnnotatedPosition(t *testing.T) {
+	fb := &flowBuilder{
+		posX:         350,
+		posY:         200,
+		spacing:      HorizontalSpacing,
+		varTypes:     map[string]string{"Items": "List of Test.Item"},
+		declaredVars: map[string]string{},
+		measurer:     &layoutMeasurer{varTypes: map[string]string{"Items": "List of Test.Item"}},
+	}
+
+	stmt := &ast.LoopStmt{
+		LoopVariable: "Item",
+		ListVariable: "Items",
+		Annotations: &ast.ActivityAnnotations{
+			Position: &ast.Position{X: 350, Y: 200},
+		},
+	}
+
+	id := fb.addLoopStatement(stmt)
+	if id == "" {
+		t.Fatal("expected loop activity ID")
+	}
+
+	loop, ok := fb.objects[len(fb.objects)-1].(*microflows.LoopedActivity)
+	if !ok {
+		t.Fatalf("expected LoopedActivity, got %T", fb.objects[len(fb.objects)-1])
+	}
+	if loop.Position.X != 350 || loop.Position.Y != 200 {
+		t.Fatalf("got loop position (%d, %d), want (350, 200)", loop.Position.X, loop.Position.Y)
+	}
+	wantNextX := 350 + loop.Size.Width/2 + HorizontalSpacing
+	if fb.posX != wantNextX {
+		t.Fatalf("got next posX %d, want %d", fb.posX, wantNextX)
+	}
+}
+
+func TestAddWhileStatement_PreservesAnnotatedPosition(t *testing.T) {
+	fb := &flowBuilder{
+		posX:         420,
+		posY:         180,
+		spacing:      HorizontalSpacing,
+		varTypes:     map[string]string{},
+		declaredVars: map[string]string{},
+		measurer:     &layoutMeasurer{varTypes: map[string]string{}},
+	}
+
+	stmt := &ast.WhileStmt{
+		Condition: &ast.BinaryExpr{
+			Left:     &ast.VariableExpr{Name: "Count"},
+			Operator: "<",
+			Right:    &ast.LiteralExpr{Kind: ast.LiteralInteger, Value: int64(10)},
+		},
+		Annotations: &ast.ActivityAnnotations{
+			Position: &ast.Position{X: 420, Y: 180},
+		},
+	}
+
+	id := fb.addWhileStatement(stmt)
+	if id == "" {
+		t.Fatal("expected while activity ID")
+	}
+
+	loop, ok := fb.objects[len(fb.objects)-1].(*microflows.LoopedActivity)
+	if !ok {
+		t.Fatalf("expected LoopedActivity, got %T", fb.objects[len(fb.objects)-1])
+	}
+	if loop.Position.X != 420 || loop.Position.Y != 180 {
+		t.Fatalf("got while position (%d, %d), want (420, 180)", loop.Position.X, loop.Position.Y)
+	}
+	wantNextX := 420 + loop.Size.Width/2 + HorizontalSpacing
+	if fb.posX != wantNextX {
+		t.Fatalf("got next posX %d, want %d", fb.posX, wantNextX)
+	}
+}
+
+func TestAddLogMessageAction_PreservesNodeExpression(t *testing.T) {
+	fb := &flowBuilder{
+		posX:     100,
+		posY:     200,
+		spacing:  HorizontalSpacing,
+		measurer: &layoutMeasurer{},
+	}
+
+	stmt := &ast.LogStmt{
+		Level: ast.LogInfo,
+		Node: &ast.ConstantRefExpr{
+			QualifiedName: ast.QualifiedName{Module: "TestModule", Name: "SecurityLogNode"},
+		},
+		Message: &ast.LiteralExpr{Kind: ast.LiteralString, Value: "User added"},
+	}
+
+	id := fb.addLogMessageAction(stmt)
+	if id == "" {
+		t.Fatal("expected log activity ID")
+	}
+
+	activity, ok := fb.objects[len(fb.objects)-1].(*microflows.ActionActivity)
+	if !ok {
+		t.Fatalf("expected ActionActivity, got %T", fb.objects[len(fb.objects)-1])
+	}
+
+	action, ok := activity.Action.(*microflows.LogMessageAction)
+	if !ok {
+		t.Fatalf("expected LogMessageAction, got %T", activity.Action)
+	}
+
+	if action.LogNodeName != "@TestModule.SecurityLogNode" {
+		t.Fatalf("got log node %q, want %q", action.LogNodeName, "@TestModule.SecurityLogNode")
+	}
+}
+
+func TestAddLogMessageAction_TemplateLiteralDoesNotKeepQuotes(t *testing.T) {
+	fb := &flowBuilder{
+		posX:     100,
+		posY:     200,
+		spacing:  HorizontalSpacing,
+		measurer: &layoutMeasurer{},
+	}
+
+	stmt := &ast.LogStmt{
+		Level: ast.LogInfo,
+		Node:  &ast.LiteralExpr{Kind: ast.LiteralString, Value: "App"},
+		Message: &ast.LiteralExpr{
+			Kind:  ast.LiteralString,
+			Value: "Order {1}",
+		},
+		Template: []ast.TemplateParam{
+			{Index: 1, Value: &ast.VariableExpr{Name: "OrderNumber"}},
+		},
+	}
+
+	id := fb.addLogMessageAction(stmt)
+	if id == "" {
+		t.Fatal("expected log activity ID")
+	}
+
+	activity, ok := fb.objects[len(fb.objects)-1].(*microflows.ActionActivity)
+	if !ok {
+		t.Fatalf("expected ActionActivity, got %T", fb.objects[len(fb.objects)-1])
+	}
+
+	action, ok := activity.Action.(*microflows.LogMessageAction)
+	if !ok {
+		t.Fatalf("expected LogMessageAction, got %T", activity.Action)
+	}
+
+	if got := action.MessageTemplate.Translations["en_US"]; got != "Order {1}" {
+		t.Fatalf("got message template %q, want %q", got, "Order {1}")
+	}
+}
+
 // =============================================================================
 // Issue #19: Long type must not be downgraded to Integer
 // =============================================================================

mdl/executor/cmd_diff_mdl.go

@@ -345,9 +345,9 @@ func microflowStatementToMDL(ctx *ExecContext, stmt ast.MicroflowStatement, inde
 		lines = append(lines, indentStr+"end loop;")
 
 	case *ast.LogStmt:
-		nodeStr := s.Node
-		if !strings.HasPrefix(nodeStr, "'") {
-			nodeStr = "'" + nodeStr + "'"
+		nodeStr := defaultLogNodeExpression
+		if s.Node != nil {
+			nodeStr = diffExpressionToString(ctx, s.Node)
 		}
 		msgStr := diffExpressionToString(ctx, s.Message)
 		stmt := fmt.Sprintf("%slog %s node %s %s", indentStr, strings.ToLower(s.Level.String()), nodeStr, msgStr)

mdl/executor/cmd_microflows_builder_calls.go

@@ -14,6 +14,11 @@ import (
 	"github.com/mendixlabs/mxcli/sdk/microflows"
 )
 
+// defaultLogNodeExpression is the quoted Mendix expression used for the log
+// node when none is specified on a LOG statement. Single source of truth shared
+// by the builder, the formatter, and cmd_diff_mdl.
+const defaultLogNodeExpression = "'Application'"
+
 // addLogMessageAction creates a LOG statement as a LogMessageAction.
 func (fb *flowBuilder) addLogMessageAction(s *ast.LogStmt) model.ID {
 	logLevel := microflows.LogLevelInfo
@@ -38,7 +43,11 @@ func (fb *flowBuilder) addLogMessageAction(s *ast.LogStmt) model.ID {
 
 	if len(s.Template) > 0 {
 		// Use provided template parameters
-		templateText = fb.exprToString(s.Message)
+		if lit, ok := s.Message.(*ast.LiteralExpr); ok && lit.Kind == ast.LiteralString {
+			templateText = fmt.Sprintf("%v", lit.Value)
+		} else {
+			templateText = fb.exprToString(s.Message)
+		}
 		// Sort parameters by index to ensure correct order
 		maxIndex := 0
 		for _, p := range s.Template {
@@ -61,10 +70,15 @@ func (fb *flowBuilder) addLogMessageAction(s *ast.LogStmt) model.ID {
 		templateParams = []string{fb.exprToString(s.Message)}
 	}
 
+	logNodeName := defaultLogNodeExpression
+	if s.Node != nil {
+		logNodeName = fb.exprToString(s.Node)
+	}
+
 	action := &microflows.LogMessageAction{
 		BaseElement: model.BaseElement{ID: model.ID(types.GenerateID())},
 		LogLevel:    logLevel,
-		LogNodeName: "'" + s.Node + "'", // Store as expression (e.g., 'TEST')
+		LogNodeName: logNodeName,
 		MessageTemplate: &model.Text{
 			BaseElement: model.BaseElement{ID: model.ID(types.GenerateID())},
 			Translations: map[string]string{

mdl/executor/cmd_microflows_builder_control.go

@@ -288,6 +288,13 @@ func (fb *flowBuilder) addLoopStatement(s *ast.LoopStmt) model.ID {
 	innerStartX := LoopPadding + iteratorSpace    // Extra offset for iterator icon and label
 	innerStartY := LoopPadding + ActivityHeight/2 // Center activities vertically with some padding
 
+	loopLeftX := fb.posX
+	loopCenterX := loopLeftX + loopWidth/2
+	if s.Annotations != nil && s.Annotations.Position != nil {
+		loopCenterX = s.Annotations.Position.X
+		loopLeftX = loopCenterX - loopWidth/2
+	}
+
 	// Add loop variable to varTypes with element type derived from list type
 	// If $ProductList is "List of MfTest.Product", then $Product is "MfTest.Product"
 	if fb.varTypes != nil {
@@ -335,7 +342,7 @@ func (fb *flowBuilder) addLoopStatement(s *ast.LoopStmt) model.ID {
 	loop := &microflows.LoopedActivity{
 		BaseMicroflowObject: microflows.BaseMicroflowObject{
 			BaseElement: model.BaseElement{ID: model.ID(types.GenerateID())},
-			Position:    model.Point{X: fb.posX + loopWidth/2, Y: fb.posY},
+			Position:    model.Point{X: loopCenterX, Y: fb.posY},
 			Size:        model.Size{Width: loopWidth, Height: loopHeight},
 		},
 		LoopSource: &microflows.IterableList{
@@ -362,7 +369,7 @@ func (fb *flowBuilder) addLoopStatement(s *ast.LoopStmt) model.ID {
 		fb.applyAnnotations(loop.ID, savedLoopAnnotations)
 	}
 
-	fb.posX += loopWidth + HorizontalSpacing
+	fb.posX = loopLeftX + loopWidth + HorizontalSpacing
 
 	return loop.ID
 }
@@ -383,6 +390,13 @@ func (fb *flowBuilder) addWhileStatement(s *ast.WhileStmt) model.ID {
 	innerStartX := LoopPadding
 	innerStartY := LoopPadding + ActivityHeight/2
 
+	loopLeftX := fb.posX
+	loopCenterX := loopLeftX + loopWidth/2
+	if s.Annotations != nil && s.Annotations.Position != nil {
+		loopCenterX = s.Annotations.Position.X
+		loopLeftX = loopCenterX - loopWidth/2
+	}
+
 	loopBuilder := &flowBuilder{
 		posX:         innerStartX,
 		posY:         innerStartY,
@@ -417,7 +431,7 @@ func (fb *flowBuilder) addWhileStatement(s *ast.WhileStmt) model.ID {
 	loop := &microflows.LoopedActivity{
 		BaseMicroflowObject: microflows.BaseMicroflowObject{
 			BaseElement: model.BaseElement{ID: model.ID(types.GenerateID())},
-			Position:    model.Point{X: fb.posX + loopWidth/2, Y: fb.posY},
+			Position:    model.Point{X: loopCenterX, Y: fb.posY},
 			Size:        model.Size{Width: loopWidth, Height: loopHeight},
 		},
 		LoopSource: &microflows.WhileLoopCondition{
@@ -439,7 +453,7 @@ func (fb *flowBuilder) addWhileStatement(s *ast.WhileStmt) model.ID {
 		fb.applyAnnotations(loop.ID, savedWhileAnnotations)
 	}
 
-	fb.posX += loopWidth + HorizontalSpacing
+	fb.posX = loopLeftX + loopWidth + HorizontalSpacing
 
 	return loop.ID
 }