DYN-6794 python script editor convert legacy tabs to spaces

src/Libraries/PythonNodeModels/Properties/Resources.en-US.resx

@@ -202,6 +202,9 @@
   <data name="PythonScriptEditorEngineDropdownTooltip" xml:space="preserve">
     <value>Select the Python version/engine to execute the script</value>
   </data>
+  <data name="PythonScriptEditorConvertTabsToSpacesButtonTooltip" xml:space="preserve">
+    <value>Convert indentation tabs to spaces...</value>
+  </data>
   <data name="PythonScriptEditorMigrationAssistantButtonTooltip" xml:space="preserve">
     <value>Convert script to Python 3...</value>
   </data>
@@ -214,4 +217,4 @@
   <data name="PythonScriptUnsavedChangesPromptTitle" xml:space="preserve">
     <value>Are you sure you want to leave?</value>
   </data>
-</root>
+</root>

src/Libraries/PythonNodeModels/Properties/Resources.resx

@@ -206,6 +206,9 @@
   <data name="PythonScriptEditorMigrationAssistantButtonTooltip" xml:space="preserve">
     <value>Convert script to Python 3...</value>
   </data>
+  <data name="PythonScriptEditorConvertTabsToSpacesButtonTooltip" xml:space="preserve">
+    <value>Convert indentation tabs to spaces...</value>
+  </data>
   <data name="PythonSearchTags" xml:space="preserve">
     <value>IronPython;CPython;</value>
   </data>
@@ -215,4 +218,4 @@
   <data name="PythonScriptUnsavedChangesPromptTitle" xml:space="preserve">
     <value>Are you sure you want to leave?</value>
   </data>
-</root>
+</root>

src/Libraries/PythonNodeModelsWpf/PythonIndentationStrategy.cs

@@ -17,7 +17,7 @@ internal class PythonIndentationStrategy : DefaultIndentationStrategy
     {
         #region Fields
 
-        const int indent_space_count = 4;
+        const int IndentSpaceCount = 4;
 
         TextEditor textEditor;
 
@@ -55,7 +55,7 @@ public override void IndentLine(TextDocument document, DocumentLine line)
             // We should indent
             else if (prevLine.EndsWith(":") && !previousIsComment)
             {
-                var ind = new string(' ', prev + indent_space_count);
+                var ind = new string(' ', prev + IndentSpaceCount);
                 document.Insert(line.Offset, ind);
             }
             else
@@ -66,17 +66,40 @@ public override void IndentLine(TextDocument document, DocumentLine line)
             }
         }
 
-        // Calculates the amount of white space leading in a string 
+        /// <summary>
+        /// Calculates the total width of leading whitespace in a string, where each space (' ') counts as 1
+        /// and each tab ('\t') counts as 4. Ensures consistent behavior for indentation and folding strategy
+        /// when transitioning from legacy code with tab indentations to modern conventions using spaces.
+        /// </summary>
         private int CalcSpace(string str)
         {
+            int count = 0;
             for (int i = 0; i < str.Length; ++i)
             {
-                if (!char.IsWhiteSpace(str[i]))
-                    return i;
-                if (i == str.Length - 1)
-                    return str.Length;
+                if (str[i] == ' ')
+                {
+                    count += 1;
+                }
+                else if (str[i] == '\t')
+                {
+                    count += 4;
+                }
+                else if (!char.IsWhiteSpace(str[i]))
+                {
+                    return count;
+                }
             }
-            return 0;
+            return count;
+        }
+
+        /// <summary>
+        /// Converts tabs to spaces in a legacy python code.
+        /// </summary>
+        /// <param name="text"></param>
+        /// <returns></returns>
+        public static string ConvertTabsToSpaces(string text)
+        {
+            return text.Replace("\t", new string(' ', IndentSpaceCount));
         }
     }
 }

src/Libraries/PythonNodeModelsWpf/PythonNodeModelsWpf.csproj

@@ -32,6 +32,8 @@
     <None Remove="Resources\reset_hover.png" />
     <None Remove="Resources\save.png" />
     <None Remove="Resources\save_hover.png" />
+    <None Remove="Resources\tabs.png" />
+    <None Remove="Resources\tabs_hover.png" />
     <None Remove="Resources\undo.png" />
     <None Remove="Resources\undo_hover.png" />
     <None Remove="Resources\zoom-in.png" />
@@ -85,6 +87,8 @@
     <Resource Include="Resources\reset_hover.png" />
     <Resource Include="Resources\save.png" />
     <Resource Include="Resources\save_hover.png" />
+    <Resource Include="Resources\tabs.png" />
+    <Resource Include="Resources\tabs_hover.png" />
     <Resource Include="Resources\undo.png" />
     <Resource Include="Resources\undo_hover.png" />
     <Resource Include="Resources\zoom-in.png" />

src/Libraries/PythonNodeModelsWpf/ScriptEditorWindow.xaml

@@ -314,6 +314,22 @@
                                    Source="/PythonNodeModelsWpf;component/Resources/convert_hover.png" />
                         </Button.Resources>
                     </Button>
+                    <Button Style="{StaticResource IconButton}"
+                            Name="ConvertTabsToSpacesButton"
+                            Click="OnConvertTabsToSpacesClicked"
+                            ToolTipService.ShowOnDisabled="True"
+                            ToolTipService.IsEnabled="True"
+                            IsEnabled="True">
+                        <Button.ToolTip>
+                            <ToolTip Content="{x:Static p:Resources.PythonScriptEditorConvertTabsToSpacesButtonTooltip}" Style="{StaticResource GenericToolTipLight}"/>
+                        </Button.ToolTip>
+                        <Button.Resources>
+                            <Image x:Key="Shape"
+                                   Source="/PythonNodeModelsWpf;component/Resources/tabs.png" />
+                            <Image x:Key="HighlightShape"
+                                   Source="/PythonNodeModelsWpf;component/Resources/tabs_hover.png" />
+                        </Button.Resources>
+                    </Button>
                     <Button Style="{StaticResource IconButton}"
                             Name="MoreInfoButton"
                             Click="OnMoreInfoClicked">

src/Libraries/PythonNodeModelsWpf/ScriptEditorWindow.xaml.cs

@@ -483,6 +483,17 @@ private void OnMigrationAssistantClicked(object sender, RoutedEventArgs e)
                 Dynamo.Logging.Categories.PythonOperations);
             NodeModel.RequestCodeMigration(e);
         }
+        private void OnConvertTabsToSpacesClicked(object sender, RoutedEventArgs e)
+        {
+            if (NodeModel == null)
+                throw new NullReferenceException(nameof(NodeModel));
+
+            if (editText.Document != null)
+            {
+                var convertedText = PythonIndentationStrategy.ConvertTabsToSpaces(editText.Document.Text);
+                editText.Document.Text = convertedText;
+            }
+        }
 
         private void OnMoreInfoClicked(object sender, RoutedEventArgs e)
         {
@@ -678,6 +689,7 @@ private void WarnUserScript()
             this.ZoomOutButton.IsEnabled = false;
             this.EngineSelectorComboBox.IsEnabled = false;
             this.MigrationAssistantButton.IsEnabled = false;
+            this.ConvertTabsToSpacesButton.IsEnabled = false;
             this.MoreInfoButton.IsEnabled = false;
             this.SaveButtonBar.Visibility = Visibility.Collapsed;
             this.UnsavedChangesStatusBar.Visibility = Visibility.Visible;
@@ -695,6 +707,7 @@ private void ResumeButton_OnClick(object sender, RoutedEventArgs e)
             this.ZoomOutButton.IsEnabled = true;
             this.EngineSelectorComboBox.IsEnabled = true;
             this.MigrationAssistantButton.IsEnabled = true;
+            this.ConvertTabsToSpacesButton.IsEnabled = true;
             this.MoreInfoButton.IsEnabled = true;
             this.SaveButtonBar.Visibility = Visibility.Visible;
             this.UnsavedChangesStatusBar.Visibility = Visibility.Collapsed;

test/Libraries/DynamoPythonTests/PythonEditTests.cs

@@ -15,6 +15,7 @@
 using Dynamo.PythonServices;
 using DynCmd = Dynamo.Models.DynamoModel;
 using System.Threading;
+using PythonNodeModelsWpf;
 
 namespace Dynamo.Tests
 {
@@ -68,6 +69,22 @@ private void UpdatePythonNodeContent(ModelBase pythonNode, string value)
             ViewModel.ExecuteCommand(command);
         }
 
+        /// <summary>
+        ///     Counts the non-overlapping occurrences of a specified substring within a given string.
+        /// </summary>
+        private int CountSubstrings(string code, string subscting)
+        {
+            int count = 0;
+            int index = code.IndexOf(subscting, 0);
+
+            while (index != -1)
+            {
+                count++;
+                index = code.IndexOf(subscting, index + subscting.Length);
+            }
+            return count;
+        }
+
         [Test]
         public void PythonScriptEdit_WorkspaceChangesReflected()
         {
@@ -202,6 +219,36 @@ public void PythonScriptEdit_UndoRedo()
             Assert.AreEqual(pynode.Script, newScript);
         }
 
+        [Test]
+        public void PythonScriptEdit_ConvertTabsToSpacesButton()
+        {
+            // Open file and get the Python node
+            var model = ViewModel.Model;
+            var examplePath = Path.Combine(TestDirectory, @"core\python", "ConvertTabsToSpaces.dyn");
+            ViewModel.OpenCommand.Execute(examplePath);
+            var pynode = model.CurrentWorkspace.Nodes.OfType<PythonNode>().First();
+
+            // Asset the node is loaded
+            Assert.NotNull(pynode, "Python node should be loaded from the file.");
+
+            // number of spaces is hard coded as providing a public property or changing the access
+            // level of PythonIndentationStrategy.ConvertTabsToSpaces is unnecessary for this purpose only
+            var spacesIndent = new string(' ', 4);
+            var tabIndent = "\t";
+
+            // Assert initial conditions : 17 tab indents and no space indents
+            Assert.IsTrue(pynode.Script.Count(c => c == '\t') == 17);
+            Assert.IsTrue(CountSubstrings(pynode.Script, spacesIndent) == 0);
+
+            // Convert tabs to spaces
+            var convertedString = PythonIndentationStrategy.ConvertTabsToSpaces(pynode.Script);
+            pynode.Script = convertedString;
+
+            // Assert the tab indents are converted to space indents
+            Assert.IsTrue(pynode.Script.Count(c => c == '\t') == 0);
+            Assert.IsTrue(CountSubstrings(pynode.Script, spacesIndent) == 17);
+        }
+
         [Test]
         public void VarInPythonScriptEdit_WorkspaceChangesReflected()
         {
@@ -448,7 +495,6 @@ public void TestWorkspaceWithMultiplePythonEngines()
         }
 
         [Test]
-
         public void Python_CanReferenceDynamoServicesExecutionSession()
         {
             // open test graph

test/core/python/ConvertTabsToSpaces.dyn

@@ -0,0 +1,106 @@
+{
+  "Uuid": "9cb0c7b0-bfa6-40a6-9d21-1fdfb4b329e0",
+  "IsCustomNode": false,
+  "Description": "",
+  "Name": "ConvertTabsToSpaces",
+  "ElementResolver": {
+    "ResolutionMap": {}
+  },
+  "Inputs": [],
+  "Outputs": [],
+  "Nodes": [
+    {
+      "ConcreteType": "PythonNodeModels.PythonNode, PythonNodeModels",
+      "Code": "# declare x\r\nx = 7\r\noutcome = \"\"\r\n\r\n# random statements\r\nif x == 5:\r\n\toutcome = \"x is 5\"\r\n\tif x == 9:\r\n\t\tif x ==10:\r\n\t\t\toutcome = \"impossible\"\r\n\telse:\r\n\t\toutcome = \"x is not 5\"\r\n\t\tif x == 1:\r\n\t\t\t# tab\tin\tcomment",
+      "Engine": "CPython3",
+      "VariableInputPorts": true,
+      "Id": "0894436c129744c3b772a4c9d44c329e",
+      "NodeType": "PythonScriptNode",
+      "Inputs": [
+        {
+          "Id": "8422c558b614406fbbb45f2ba0394149",
+          "Name": "IN[0]",
+          "Description": "Input #0",
+          "UsingDefaultValue": false,
+          "Level": 2,
+          "UseLevels": false,
+          "KeepListStructure": false
+        }
+      ],
+      "Outputs": [
+        {
+          "Id": "f871bd7ad08648a6b6cc660024641eb1",
+          "Name": "OUT",
+          "Description": "Result of the python script",
+          "UsingDefaultValue": false,
+          "Level": 2,
+          "UseLevels": false,
+          "KeepListStructure": false
+        }
+      ],
+      "Replication": "Disabled",
+      "Description": "Runs an embedded Python script."
+    }
+  ],
+  "Connectors": [],
+  "Dependencies": [],
+  "NodeLibraryDependencies": [],
+  "EnableLegacyPolyCurveBehavior": true,
+  "Thumbnail": "",
+  "GraphDocumentationURL": null,
+  "ExtensionWorkspaceData": [
+    {
+      "ExtensionGuid": "28992e1d-abb9-417f-8b1b-05e053bee670",
+      "Name": "Properties",
+      "Version": "3.1",
+      "Data": {}
+    }
+  ],
+  "Author": "",
+  "Linting": {
+    "activeLinter": "None",
+    "activeLinterId": "7b75fb44-43fd-4631-a878-29f4d5d8399a",
+    "warningCount": 0,
+    "errorCount": 0
+  },
+  "Bindings": [],
+  "View": {
+    "Dynamo": {
+      "ScaleFactor": 1.0,
+      "HasRunWithoutCrash": true,
+      "IsVisibleInDynamoLibrary": true,
+      "Version": "3.1.0.3411",
+      "RunType": "Manual",
+      "RunPeriod": "1000"
+    },
+    "Camera": {
+      "Name": "_Background Preview",
+      "EyeX": -17.0,
+      "EyeY": 24.0,
+      "EyeZ": 50.0,
+      "LookX": 12.0,
+      "LookY": -13.0,
+      "LookZ": -58.0,
+      "UpX": 0.0,
+      "UpY": 1.0,
+      "UpZ": 0.0
+    },
+    "ConnectorPins": [],
+    "NodeViews": [
+      {
+        "Id": "0894436c129744c3b772a4c9d44c329e",
+        "Name": "Python Script",
+        "IsSetAsInput": false,
+        "IsSetAsOutput": false,
+        "Excluded": false,
+        "ShowGeometry": true,
+        "X": 323.0,
+        "Y": 217.0
+      }
+    ],
+    "Annotations": [],
+    "X": -266.0446043165468,
+    "Y": -33.539568345323744,
+    "Zoom": 0.9165467625899281
+  }
+}