fix: harden microflow describe roundtrip

MDL text produced by `describe microflow` was failing to re-parse on
several shapes: multiline captions/messages lost their newlines, tabs
were silently dropped when unquoting strings, and loop positions
anchored with `@position` drifted by half a loop width per roundtrip.

Centralise string escaping in an mdlQuote helper that doubles single
quotes and encodes `\n`, `\r`, `\t`, and `\\`. Switch every call site
(`cmd_microflows_show.go`, `cmd_microflows_show_helpers.go`,
`cmd_microflows_format_action.go`, `cmd_microflows_helpers.go`,
`cmd_pages_describe_output.go`) to use it. Mirror the encoding in the
visitor by rewriting `unquoteString` to walk the input and decode each
escape explicitly instead of doing naive sequential `ReplaceAll` calls,
which mangled `\\n` and similar sequences.

Loops now compute `loopLeftX`/`loopCenterX` up front and use the
annotated `@position` when set, then advance `fb.posX` past the actual
left edge of the loop instead of the stale pre-annotation position.
`addWhileStatement` gets the same treatment.

Regression tests cover:
- `emitObjectAnnotations` emitting escaped `@caption` / `@annotation`
- `formatAction` for `ShowMessage` and `LogMessage` with multiline text
- `unquoteString` decoding `\n`, `\t`, `\\`, and doubled quotes
- `addLoopStatement` / `addWhileStatement` honouring `@position` and
  leaving `fb.posX` past the loop's right edge

Author: hjotha

mdl/executor/bugfix_regression_test.go

@@ -65,6 +65,81 @@ 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)
+	}
+}
+
 // =============================================================================
 // Issue #19: Long type must not be downgraded to Integer
 // =============================================================================

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
 }

mdl/executor/cmd_microflows_format_action.go

@@ -372,8 +372,7 @@ func formatAction(
 			if text, ok := a.MessageTemplate.Translations["en_US"]; ok {
 				message = text
 			}
-			// Wrap message in quotes for MDL syntax (escape any existing single quotes)
-			message = "'" + strings.ReplaceAll(message, "'", "''") + "'"
+			message = mdlQuote(message)
 		}
 
 		// Build WITH clause if there are template parameters
@@ -448,7 +447,7 @@ func formatAction(
 				}
 			case *microflows.EntityTypeCodeActionParameterValue:
 				if v.Entity != "" {
-					valueStr = "'" + v.Entity + "'"
+					valueStr = mdlQuote(v.Entity)
 				}
 			}
 			params = append(params, fmt.Sprintf("%s = %s", paramName, valueStr))
@@ -549,8 +548,7 @@ func formatAction(
 			if text, ok := a.Template.Translations["en_US"]; ok {
 				message = text
 			}
-			// Wrap message in quotes for MDL syntax (escape any existing single quotes)
-			message = "'" + strings.ReplaceAll(message, "'", "''") + "'"
+			message = mdlQuote(message)
 		}
 		result := fmt.Sprintf("show message %s type %s", message, msgType)
 		if len(a.TemplateParameters) > 0 {
@@ -569,8 +567,7 @@ func formatAction(
 			if text, ok := a.Template.Translations["en_US"]; ok {
 				msgText = text
 			}
-			// Wrap message in quotes for MDL syntax (escape any existing single quotes)
-			msgText = "'" + strings.ReplaceAll(msgText, "'", "''") + "'"
+			msgText = mdlQuote(msgText)
 		}
 		// Build attribute path from variable and attribute name
 		// AttributeName format: Module.Entity.Attribute
@@ -636,7 +633,7 @@ func formatAction(
 		return formatWorkflowOperationAction(ctx, a)
 
 	case *microflows.SetTaskOutcomeAction:
-		return fmt.Sprintf("set task outcome $%s '%s';", a.WorkflowTaskVariable, a.OutcomeValue)
+		return fmt.Sprintf("set task outcome $%s %s;", a.WorkflowTaskVariable, mdlQuote(a.OutcomeValue))
 
 	case *microflows.OpenUserTaskAction:
 		return fmt.Sprintf("open user task $%s;", a.UserTaskVariable)
@@ -684,7 +681,7 @@ func formatWorkflowOperationAction(ctx *ExecContext, a *microflows.WorkflowOpera
 	switch op := a.Operation.(type) {
 	case *microflows.AbortOperation:
 		if op.Reason != "" {
-			return fmt.Sprintf("workflow operation abort $%s reason '%s';", op.WorkflowVariable, strings.ReplaceAll(op.Reason, "'", "''"))
+			return fmt.Sprintf("workflow operation abort $%s reason %s;", op.WorkflowVariable, mdlQuote(op.Reason))
 		}
 		return fmt.Sprintf("workflow operation abort $%s;", op.WorkflowVariable)
 	case *microflows.ContinueOperation:
@@ -843,7 +840,7 @@ func formatRestCallAction(ctx *ExecContext, a *microflows.RestCallAction) string
 	// URL
 	url := "''"
 	if a.HttpConfiguration != nil && a.HttpConfiguration.LocationTemplate != "" {
-		url = "'" + strings.ReplaceAll(a.HttpConfiguration.LocationTemplate, "'", "''") + "'"
+		url = mdlQuote(a.HttpConfiguration.LocationTemplate)
 	}
 	sb.WriteString(url)
 
@@ -862,9 +859,9 @@ func formatRestCallAction(ctx *ExecContext, a *microflows.RestCallAction) string
 	// Headers
 	if a.HttpConfiguration != nil && len(a.HttpConfiguration.CustomHeaders) > 0 {
 		for _, h := range a.HttpConfiguration.CustomHeaders {
-			sb.WriteString("\n    header '")
-			sb.WriteString(strings.ReplaceAll(h.Name, "'", "''"))
-			sb.WriteString("' = ")
+			sb.WriteString("\n    header ")
+			sb.WriteString(mdlQuote(h.Name))
+			sb.WriteString(" = ")
 			sb.WriteString(h.Value)
 		}
 	}
@@ -882,9 +879,8 @@ func formatRestCallAction(ctx *ExecContext, a *microflows.RestCallAction) string
 		switch rh := a.RequestHandling.(type) {
 		case *microflows.CustomRequestHandling:
 			if rh.Template != "" {
-				sb.WriteString("\n    body '")
-				sb.WriteString(strings.ReplaceAll(rh.Template, "'", "''"))
-				sb.WriteString("'")
+				sb.WriteString("\n    body ")
+				sb.WriteString(mdlQuote(rh.Template))
 				// Add template parameters if present
 				if len(rh.TemplateParams) > 0 {
 					sb.WriteString(" with (")

mdl/executor/cmd_microflows_format_action_test.go

@@ -462,6 +462,20 @@ func TestFormatAction_ShowMessage_EscapesQuotes(t *testing.T) {
 	}
 }
 
+func TestFormatAction_ShowMessage_EscapesMultiline(t *testing.T) {
+	e := newTestExecutor()
+	action := &microflows.ShowMessageAction{
+		Type: microflows.MessageTypeInformation,
+		Template: &model.Text{
+			Translations: map[string]string{"en_US": "Line 1\nLine 2\tTabbed"},
+		},
+	}
+	got := e.formatAction(action, nil, nil)
+	if got != "show message 'Line 1\\nLine 2\\tTabbed' type Information;" {
+		t.Errorf("got %q", got)
+	}
+}
+
 func TestFormatAction_ValidationFeedback(t *testing.T) {
 	e := newTestExecutor()
 	action := &microflows.ValidationFeedbackAction{
@@ -511,6 +525,22 @@ func TestFormatAction_LogMessage_WithTemplateParams(t *testing.T) {
 	}
 }
 
+func TestFormatAction_LogMessage_EscapesMultiline(t *testing.T) {
+	e := newTestExecutor()
+	action := &microflows.LogMessageAction{
+		LogLevel:    microflows.LogLevelInfo,
+		LogNodeName: "'App'",
+		MessageTemplate: &model.Text{
+			Translations: map[string]string{"en_US": "Line 1\nLine 2"},
+		},
+	}
+	got := e.formatAction(action, nil, nil)
+	want := "LOG INFO NODE 'App' 'Line 1\\nLine 2';"
+	if got != want {
+		t.Errorf("got %q, want %q", got, want)
+	}
+}
+
 func TestFormatAction_UnknownAction(t *testing.T) {
 	e := newTestExecutor()
 	action := &microflows.UnknownAction{TypeName: "SomeNewAction"}

mdl/executor/cmd_microflows_helpers.go

@@ -182,10 +182,7 @@ func expressionToString(expr ast.Expression) string {
 	case *ast.LiteralExpr:
 		switch e.Kind {
 		case ast.LiteralString:
-			// Escape single quotes for Mendix expression syntax (use '' inside strings)
-			strVal := fmt.Sprintf("%v", e.Value)
-			strVal = strings.ReplaceAll(strVal, `'`, `''`)
-			return "'" + strVal + "'"
+			return mdlQuote(fmt.Sprintf("%v", e.Value))
 		case ast.LiteralBoolean:
 			if e.Value.(bool) {
 				return "true"

mdl/executor/cmd_microflows_show.go

@@ -267,7 +267,7 @@ func describeMicroflow(ctx *ExecContext, name ast.QualifiedName) error {
 
 	// Folder
 	if folderPath := h.BuildFolderPath(targetMf.ContainerID); folderPath != "" {
-		lines = append(lines, fmt.Sprintf("folder '%s'", folderPath))
+		lines = append(lines, fmt.Sprintf("folder %s", mdlQuote(folderPath)))
 	}
 
 	// BEGIN block
@@ -402,7 +402,7 @@ func describeNanoflow(ctx *ExecContext, name ast.QualifiedName) error {
 
 	// Folder
 	if folderPath := h.BuildFolderPath(targetNf.ContainerID); folderPath != "" {
-		lines = append(lines, fmt.Sprintf("folder '%s'", folderPath))
+		lines = append(lines, fmt.Sprintf("folder %s", mdlQuote(folderPath)))
 	}
 
 	// BEGIN block with activities

mdl/executor/cmd_microflows_show_helpers.go

@@ -76,8 +76,7 @@ func emitObjectAnnotations(obj microflows.MicroflowObject, lines *[]string, inde
 			*lines = append(*lines, indentStr+"@excluded")
 		}
 		if !activity.AutoGenerateCaption && activity.Caption != "" {
-			escapedCaption := strings.ReplaceAll(activity.Caption, "'", "''")
-			*lines = append(*lines, indentStr+fmt.Sprintf("@caption '%s'", escapedCaption))
+			*lines = append(*lines, indentStr+fmt.Sprintf("@caption %s", mdlQuote(activity.Caption)))
 		}
 		if activity.BackgroundColor != "" && activity.BackgroundColor != "Default" {
 			*lines = append(*lines, indentStr+fmt.Sprintf("@color %s", activity.BackgroundColor))
@@ -96,8 +95,7 @@ func emitObjectAnnotations(obj microflows.MicroflowObject, lines *[]string, inde
 	// @annotation (attached Annotation objects)
 	if annotationsByTarget != nil {
 		for _, caption := range annotationsByTarget[currentID] {
-			escapedCaption := strings.ReplaceAll(caption, "'", "''")
-			*lines = append(*lines, indentStr+fmt.Sprintf("@annotation '%s'", escapedCaption))
+			*lines = append(*lines, indentStr+fmt.Sprintf("@annotation %s", mdlQuote(caption)))
 		}
 	}
 }

mdl/executor/cmd_microflows_show_helpers_test.go

@@ -3,8 +3,10 @@
 package executor
 
 import (
+	"strings"
 	"testing"
 
+	"github.com/mendixlabs/mxcli/model"
 	"github.com/mendixlabs/mxcli/sdk/microflows"
 )
 
@@ -129,6 +131,34 @@ func TestFindNormalFlows_AllErrors(t *testing.T) {
 	}
 }
 
+func TestEmitObjectAnnotations_EscapesMultilineText(t *testing.T) {
+	obj := &microflows.ActionActivity{
+		BaseActivity: microflows.BaseActivity{
+			BaseMicroflowObject: microflows.BaseMicroflowObject{
+				BaseElement: model.BaseElement{ID: mkID("act")},
+				Position:    model.Point{X: 100, Y: 200},
+			},
+			Caption:             "Caption\nLine",
+			AutoGenerateCaption: false,
+		},
+	}
+
+	annotationsByTarget := map[model.ID][]string{
+		mkID("act"): {"Note\nLine\tTabbed"},
+	}
+
+	var lines []string
+	emitObjectAnnotations(obj, &lines, "", annotationsByTarget)
+
+	got := strings.Join(lines, "\n")
+	if !strings.Contains(got, "@caption 'Caption\\nLine'") {
+		t.Fatalf("expected escaped caption, got:\n%s", got)
+	}
+	if !strings.Contains(got, "@annotation 'Note\\nLine\\tTabbed'") {
+		t.Fatalf("expected escaped annotation, got:\n%s", got)
+	}
+}
+
 // =============================================================================
 // formatErrorHandlingSuffix
 // =============================================================================

mdl/executor/cmd_pages_describe_output.go

@@ -13,10 +13,16 @@ import (
 	"go.mongodb.org/mongo-driver/bson/primitive"
 )
 
-// mdlQuote wraps a string in single quotes, escaping any embedded single quotes
-// by doubling them (MDL convention: 'it”s here').
+// mdlQuote wraps a string in single quotes and escapes MDL-sensitive characters.
 func mdlQuote(s string) string {
-	return "'" + strings.ReplaceAll(s, "'", "''") + "'"
+	escaped := strings.NewReplacer(
+		"\\", "\\\\",
+		"\n", "\\n",
+		"\r", "\\r",
+		"\t", "\\t",
+		"'", "''",
+	).Replace(s)
+	return "'" + escaped + "'"
 }
 
 // appendDataGridPagingProps appends non-default paging properties for DataGrid2.