trim whitespace when deleting new line character (microsoft#210870)

* trim whitespace after new line character deletion

* trimming whitespace after deleting newline character + tests --  feature request microsoft#134898

* Implement deleting right at end of line includes leading whitespace

---------

Co-authored-by: Alexandru Dima <[email protected]>

Author: alexdima

src/vs/editor/common/config/editorOptions.ts

@@ -735,6 +735,11 @@ export interface IEditorOptions {
 	 * Inserting and deleting whitespace follows tab stops.
 	 */
 	useTabStops?: boolean;
+	/**
+	 * Controls whether the editor should automatically remove indentation whitespace when joining lines with Delete.
+	 * Defaults to false.
+	 */
+	trimWhitespaceOnDelete?: boolean;
 	/**
 	 * The font family
 	 */
@@ -5721,6 +5726,7 @@ export const enum EditorOption {
 	suggestSelection,
 	tabCompletion,
 	tabIndex,
+	trimWhitespaceOnDelete,
 	unicodeHighlighting,
 	unusualLineTerminators,
 	useShadowDOM,
@@ -6512,6 +6518,10 @@ export const EditorOptions = {
 		EditorOption.tabIndex, 'tabIndex',
 		0, -1, Constants.MAX_SAFE_SMALL_INTEGER
 	)),
+	trimWhitespaceOnDelete: register(new EditorBooleanOption(
+		EditorOption.trimWhitespaceOnDelete, 'trimWhitespaceOnDelete', false,
+		{ description: nls.localize('trimWhitespaceOnDelete', "Controls whether the editor will also delete the next line's indentation whitespace when deleting a newline.") }
+	)),
 	unicodeHighlight: register(new UnicodeHighlight()),
 	unusualLineTerminators: register(new EditorStringEnumOption(
 		EditorOption.unusualLineTerminators, 'unusualLineTerminators',

src/vs/editor/common/cursor/cursorDeleteOperations.ts

@@ -23,18 +23,7 @@ export class DeleteOperations {
 		for (let i = 0, len = selections.length; i < len; i++) {
 			const selection = selections[i];
 
-			let deleteSelection: Range = selection;
-
-			if (deleteSelection.isEmpty()) {
-				const position = selection.getPosition();
-				const rightOfPosition = MoveOperations.right(config, model, position);
-				deleteSelection = new Range(
-					rightOfPosition.lineNumber,
-					rightOfPosition.column,
-					position.lineNumber,
-					position.column
-				);
-			}
+			const deleteSelection = this.getDeleteRightRange(selection, model, config);
 
 			if (deleteSelection.isEmpty()) {
 				// Probably at end of file => ignore
@@ -51,6 +40,37 @@ export class DeleteOperations {
 		return [shouldPushStackElementBefore, commands];
 	}
 
+	private static getDeleteRightRange(selection: Selection, model: ICursorSimpleModel, config: CursorConfiguration): Range {
+		if (!selection.isEmpty()) {
+			return selection;
+		}
+
+		const position = selection.getPosition();
+		const rightOfPosition = MoveOperations.right(config, model, position);
+
+		if (config.trimWhitespaceOnDelete && rightOfPosition.lineNumber !== position.lineNumber) {
+			// Smart line join (deleting leading whitespace) is on
+			// (and) Delete is happening at the end of a line
+			const firstNonWhitespaceColumn = model.getLineFirstNonWhitespaceColumn(rightOfPosition.lineNumber);
+			if (firstNonWhitespaceColumn > 0) {
+				// The next line has content
+				return new Range(
+					rightOfPosition.lineNumber,
+					firstNonWhitespaceColumn,
+					position.lineNumber,
+					position.column
+				);
+			}
+		}
+
+		return new Range(
+			rightOfPosition.lineNumber,
+			rightOfPosition.column,
+			position.lineNumber,
+			position.column
+		);
+	}
+
 	public static isAutoClosingPairDelete(
 		autoClosingDelete: EditorAutoClosingEditStrategy,
 		autoClosingBrackets: EditorAutoClosingStrategy,
@@ -150,7 +170,7 @@ export class DeleteOperations {
 		const commands: Array<ICommand | null> = [];
 		let shouldPushStackElementBefore = (prevEditOperationType !== EditOperationType.DeletingLeft);
 		for (let i = 0, len = selections.length; i < len; i++) {
-			const deleteRange = DeleteOperations.getDeleteRange(selections[i], model, config);
+			const deleteRange = DeleteOperations.getDeleteLeftRange(selections[i], model, config);
 
 			// Ignore empty delete ranges, as they have no effect
 			// They happen if the cursor is at the beginning of the file.
@@ -169,7 +189,7 @@ export class DeleteOperations {
 
 	}
 
-	private static getDeleteRange(selection: Selection, model: ICursorSimpleModel, config: CursorConfiguration,): Range {
+	private static getDeleteLeftRange(selection: Selection, model: ICursorSimpleModel, config: CursorConfiguration): Range {
 		if (!selection.isEmpty()) {
 			return selection;
 		}

src/vs/editor/common/cursorCommon.ts

@@ -60,6 +60,7 @@ export class CursorConfiguration {
 	public readonly lineHeight: number;
 	public readonly typicalHalfwidthCharacterWidth: number;
 	public readonly useTabStops: boolean;
+	public readonly trimWhitespaceOnDelete: boolean;
 	public readonly wordSeparators: string;
 	public readonly emptySelectionClipboard: boolean;
 	public readonly copyWithSyntaxHighlighting: boolean;
@@ -98,6 +99,7 @@ export class CursorConfiguration {
 			|| e.hasChanged(EditorOption.autoClosingOvertype)
 			|| e.hasChanged(EditorOption.autoSurround)
 			|| e.hasChanged(EditorOption.useTabStops)
+			|| e.hasChanged(EditorOption.trimWhitespaceOnDelete)
 			|| e.hasChanged(EditorOption.fontInfo)
 			|| e.hasChanged(EditorOption.readOnly)
 			|| e.hasChanged(EditorOption.wordSegmenterLocales)
@@ -126,6 +128,7 @@ export class CursorConfiguration {
 		this.typicalHalfwidthCharacterWidth = fontInfo.typicalHalfwidthCharacterWidth;
 		this.pageSize = Math.max(1, Math.floor(layoutInfo.height / this.lineHeight) - 2);
 		this.useTabStops = options.get(EditorOption.useTabStops);
+		this.trimWhitespaceOnDelete = options.get(EditorOption.trimWhitespaceOnDelete);
 		this.wordSeparators = options.get(EditorOption.wordSeparators);
 		this.emptySelectionClipboard = options.get(EditorOption.emptySelectionClipboard);
 		this.copyWithSyntaxHighlighting = options.get(EditorOption.copyWithSyntaxHighlighting);

src/vs/editor/common/standalone/standaloneEnums.ts

@@ -313,37 +313,38 @@ export enum EditorOption {
 	suggestSelection = 136,
 	tabCompletion = 137,
 	tabIndex = 138,
-	unicodeHighlighting = 139,
-	unusualLineTerminators = 140,
-	useShadowDOM = 141,
-	useTabStops = 142,
-	wordBreak = 143,
-	wordSegmenterLocales = 144,
-	wordSeparators = 145,
-	wordWrap = 146,
-	wordWrapBreakAfterCharacters = 147,
-	wordWrapBreakBeforeCharacters = 148,
-	wordWrapColumn = 149,
-	wordWrapOverride1 = 150,
-	wordWrapOverride2 = 151,
-	wrappingIndent = 152,
-	wrappingStrategy = 153,
-	showDeprecated = 154,
-	inertialScroll = 155,
-	inlayHints = 156,
-	wrapOnEscapedLineFeeds = 157,
-	effectiveCursorStyle = 158,
-	editorClassName = 159,
-	pixelRatio = 160,
-	tabFocusMode = 161,
-	layoutInfo = 162,
-	wrappingInfo = 163,
-	defaultColorDecorators = 164,
-	colorDecoratorsActivatedOn = 165,
-	inlineCompletionsAccessibilityVerbose = 166,
-	effectiveEditContext = 167,
-	scrollOnMiddleClick = 168,
-	effectiveAllowVariableFonts = 169
+	trimWhitespaceOnDelete = 139,
+	unicodeHighlighting = 140,
+	unusualLineTerminators = 141,
+	useShadowDOM = 142,
+	useTabStops = 143,
+	wordBreak = 144,
+	wordSegmenterLocales = 145,
+	wordSeparators = 146,
+	wordWrap = 147,
+	wordWrapBreakAfterCharacters = 148,
+	wordWrapBreakBeforeCharacters = 149,
+	wordWrapColumn = 150,
+	wordWrapOverride1 = 151,
+	wordWrapOverride2 = 152,
+	wrappingIndent = 153,
+	wrappingStrategy = 154,
+	showDeprecated = 155,
+	inertialScroll = 156,
+	inlayHints = 157,
+	wrapOnEscapedLineFeeds = 158,
+	effectiveCursorStyle = 159,
+	editorClassName = 160,
+	pixelRatio = 161,
+	tabFocusMode = 162,
+	layoutInfo = 163,
+	wrappingInfo = 164,
+	defaultColorDecorators = 165,
+	colorDecoratorsActivatedOn = 166,
+	inlineCompletionsAccessibilityVerbose = 167,
+	effectiveEditContext = 168,
+	scrollOnMiddleClick = 169,
+	effectiveAllowVariableFonts = 170
 }
 
 /**

src/vs/monaco.d.ts

@@ -3886,6 +3886,11 @@ declare namespace monaco.editor {
 		 * Inserting and deleting whitespace follows tab stops.
 		 */
 		useTabStops?: boolean;
+		/**
+		 * Controls whether the editor should automatically remove indentation whitespace when joining lines with Delete.
+		 * Defaults to false.
+		 */
+		trimWhitespaceOnDelete?: boolean;
 		/**
 		 * The font family
 		 */
@@ -5188,37 +5193,38 @@ declare namespace monaco.editor {
 		suggestSelection = 136,
 		tabCompletion = 137,
 		tabIndex = 138,
-		unicodeHighlighting = 139,
-		unusualLineTerminators = 140,
-		useShadowDOM = 141,
-		useTabStops = 142,
-		wordBreak = 143,
-		wordSegmenterLocales = 144,
-		wordSeparators = 145,
-		wordWrap = 146,
-		wordWrapBreakAfterCharacters = 147,
-		wordWrapBreakBeforeCharacters = 148,
-		wordWrapColumn = 149,
-		wordWrapOverride1 = 150,
-		wordWrapOverride2 = 151,
-		wrappingIndent = 152,
-		wrappingStrategy = 153,
-		showDeprecated = 154,
-		inertialScroll = 155,
-		inlayHints = 156,
-		wrapOnEscapedLineFeeds = 157,
-		effectiveCursorStyle = 158,
-		editorClassName = 159,
-		pixelRatio = 160,
-		tabFocusMode = 161,
-		layoutInfo = 162,
-		wrappingInfo = 163,
-		defaultColorDecorators = 164,
-		colorDecoratorsActivatedOn = 165,
-		inlineCompletionsAccessibilityVerbose = 166,
-		effectiveEditContext = 167,
-		scrollOnMiddleClick = 168,
-		effectiveAllowVariableFonts = 169
+		trimWhitespaceOnDelete = 139,
+		unicodeHighlighting = 140,
+		unusualLineTerminators = 141,
+		useShadowDOM = 142,
+		useTabStops = 143,
+		wordBreak = 144,
+		wordSegmenterLocales = 145,
+		wordSeparators = 146,
+		wordWrap = 147,
+		wordWrapBreakAfterCharacters = 148,
+		wordWrapBreakBeforeCharacters = 149,
+		wordWrapColumn = 150,
+		wordWrapOverride1 = 151,
+		wordWrapOverride2 = 152,
+		wrappingIndent = 153,
+		wrappingStrategy = 154,
+		showDeprecated = 155,
+		inertialScroll = 156,
+		inlayHints = 157,
+		wrapOnEscapedLineFeeds = 158,
+		effectiveCursorStyle = 159,
+		editorClassName = 160,
+		pixelRatio = 161,
+		tabFocusMode = 162,
+		layoutInfo = 163,
+		wrappingInfo = 164,
+		defaultColorDecorators = 165,
+		colorDecoratorsActivatedOn = 166,
+		inlineCompletionsAccessibilityVerbose = 167,
+		effectiveEditContext = 168,
+		scrollOnMiddleClick = 169,
+		effectiveAllowVariableFonts = 170
 	}
 
 	export const EditorOptions: {
@@ -5367,6 +5373,7 @@ declare namespace monaco.editor {
 		suggestSelection: IEditorOption<EditorOption.suggestSelection, 'first' | 'recentlyUsed' | 'recentlyUsedByPrefix'>;
 		tabCompletion: IEditorOption<EditorOption.tabCompletion, 'on' | 'off' | 'onlySnippets'>;
 		tabIndex: IEditorOption<EditorOption.tabIndex, number>;
+		trimWhitespaceOnDelete: IEditorOption<EditorOption.trimWhitespaceOnDelete, boolean>;
 		unicodeHighlight: IEditorOption<EditorOption.unicodeHighlighting, any>;
 		unusualLineTerminators: IEditorOption<EditorOption.unusualLineTerminators, 'off' | 'auto' | 'prompt'>;
 		useShadowDOM: IEditorOption<EditorOption.useShadowDOM, boolean>;