When folding markdown headers, leave single new line before next header

extensions/markdown/src/features/foldingProvider.ts

@@ -31,6 +31,9 @@ export default class MarkdownFoldingProvider implements vscode.FoldingProvider {
 			for (let i = startIndex + 1; i < toc.length; ++i) {
 				if (toc[i].level <= entry.level) {
 					end = toc[i].line - 1;
+					if (document.lineAt(end).isEmptyOrWhitespace && end >= start + 1) {
+						end = end - 1;
+					}
 					break;
 				}
 			}

extensions/markdown/src/test/foldingProvider.test.ts

@@ -0,0 +1,99 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import * as vscode from 'vscode';
+import 'mocha';
+
+import { MarkdownEngine } from '../markdownEngine';
+import { MarkdownContributions } from '../markdownExtensions';
+import MarkdownFoldingProvider from '../features/foldingProvider';
+import { InMemoryDocument } from './inMemoryDocument';
+
+const testFileName = vscode.Uri.parse('test.md');
+
+suite('markdown.FoldingProvider', () => {
+	test('Should not return anything for empty document', async () => {
+		const folds = await getFoldsForDocument(``);
+		assert.strictEqual(folds.ranges.length, 0);
+	});
+
+	test('Should not return anything for document without headers', async () => {
+		const folds = await getFoldsForDocument(`a
+**b** afas
+a#b
+a`);
+		assert.strictEqual(folds.ranges.length, 0);
+	});
+
+	test('Should fold from header to end of document', async () => {
+		const folds = await getFoldsForDocument(`a
+# b
+c
+d`);
+		assert.strictEqual(folds.ranges.length, 1);
+		const firstFold = folds.ranges[0];
+		assert.strictEqual(firstFold.startLine, 1);
+		assert.strictEqual(firstFold.endLine, 3);
+	});
+
+	test('Should leave single newline before next header', async () => {
+		const folds = await getFoldsForDocument(`
+# a
+x
+
+# b
+y`);
+		assert.strictEqual(folds.ranges.length, 2);
+		const firstFold = folds.ranges[0];
+		assert.strictEqual(firstFold.startLine, 1);
+		assert.strictEqual(firstFold.endLine, 3);
+	});
+
+	test('Should collapse multuple newlines to single newline before next header', async () => {
+		const folds = await getFoldsForDocument(`
+# a
+x
+
+
+
+# b
+y`);
+		assert.strictEqual(folds.ranges.length, 2);
+		const firstFold = folds.ranges[0];
+		assert.strictEqual(firstFold.startLine, 1);
+		assert.strictEqual(firstFold.endLine, 5);
+	});
+
+	test('Should not collapse if there is no newline before next header', async () => {
+		const folds = await getFoldsForDocument(`
+# a
+x
+# b
+y`);
+		assert.strictEqual(folds.ranges.length, 2);
+		const firstFold = folds.ranges[0];
+		assert.strictEqual(firstFold.startLine, 1);
+		assert.strictEqual(firstFold.endLine, 2);
+	});
+
+});
+
+
+async function getFoldsForDocument(contents: string) {
+	const doc = new InMemoryDocument(testFileName, contents);
+	const provider = new MarkdownFoldingProvider(newEngine());
+	return await provider.provideFoldingRanges(doc, {}, new vscode.CancellationTokenSource().token);
+}
+
+function newEngine(): MarkdownEngine {
+	return new MarkdownEngine(new class implements MarkdownContributions {
+		readonly previewScripts: vscode.Uri[] = [];
+		readonly previewStyles: vscode.Uri[] = [];
+		readonly previewResourceRoots: vscode.Uri[] = [];
+		readonly markdownItPlugins: Promise<(md: any) => any>[]  = [];
+	});
+}
+

extensions/markdown/src/test/inMemoryDocument.ts

@@ -0,0 +1,61 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+
+export class InMemoryDocument implements vscode.TextDocument {
+	private readonly _lines: string[];
+
+	constructor(
+		public readonly uri: vscode.Uri,
+		private readonly _contents: string
+	) {
+		this._lines = this._contents.split(/\n/g);
+	}
+
+	fileName: string = '';
+	isUntitled: boolean = false;
+	languageId: string = '';
+	version: number = 1;
+	isDirty: boolean = false;
+	isClosed: boolean = false;
+	eol: vscode.EndOfLine = vscode.EndOfLine.LF;
+
+	get lineCount(): number {
+		return this._lines.length;
+	}
+
+	lineAt(line: any): vscode.TextLine {
+		return {
+			lineNumber: line,
+			text: this._lines[line],
+			range: new vscode.Range(0, 0, 0, 0),
+			firstNonWhitespaceCharacterIndex: 0,
+			rangeIncludingLineBreak: new vscode.Range(0, 0, 0, 0),
+			isEmptyOrWhitespace: false
+		};
+	}
+	offsetAt(_position: vscode.Position): never {
+		throw new Error('Method not implemented.');
+	}
+	positionAt(_offset: number): never {
+		throw new Error('Method not implemented.');
+	}
+	getText(_range?: vscode.Range | undefined): string {
+		return this._contents;
+	}
+	getWordRangeAtPosition(_position: vscode.Position, _regex?: RegExp | undefined): never {
+		throw new Error('Method not implemented.');
+	}
+	validateRange(_range: vscode.Range): never {
+		throw new Error('Method not implemented.');
+	}
+	validatePosition(_position: vscode.Position): never {
+		throw new Error('Method not implemented.');
+	}
+	save(): never {
+		throw new Error('Method not implemented.');
+	}
+}

extensions/markdown/src/test/tableOfContentsProvider.test.ts

@@ -10,6 +10,7 @@ import 'mocha';
 import { TableOfContentsProvider } from '../tableOfContentsProvider';
 import { MarkdownEngine } from '../markdownEngine';
 import { MarkdownContributions } from '../markdownExtensions';
+import { InMemoryDocument } from './inMemoryDocument';
 
 const testFileName = vscode.Uri.parse('test.md');
 
@@ -83,62 +84,6 @@ suite('markdown.TableOfContentsProvider', () => {
 	});
 });
 
-class InMemoryDocument implements vscode.TextDocument {
-	private readonly _lines: string[];
-
-	constructor(
-		public readonly uri: vscode.Uri,
-		private readonly _contents: string
-	) {
-		this._lines = this._contents.split(/\n/g);
-	}
-
-	fileName: string = '';
-	isUntitled: boolean = false;
-	languageId: string = '';
-	version: number = 1;
-	isDirty: boolean = false;
-	isClosed: boolean = false;
-	eol: vscode.EndOfLine = vscode.EndOfLine.LF;
-
-	get lineCount(): number {
-		return this._lines.length;
-	}
-
-	lineAt(line: any): vscode.TextLine {
-		return {
-			lineNumber: line,
-			text: this._lines[line],
-			range: new vscode.Range(0, 0, 0, 0),
-			firstNonWhitespaceCharacterIndex: 0,
-			rangeIncludingLineBreak: new vscode.Range(0, 0, 0, 0),
-			isEmptyOrWhitespace: false
-		};
-	}
-	offsetAt(_position: vscode.Position): never {
-		throw new Error('Method not implemented.');
-	}
-	positionAt(_offset: number): never {
-		throw new Error('Method not implemented.');
-	}
-	getText(_range?: vscode.Range | undefined): string {
-		return this._contents;
-	}
-	getWordRangeAtPosition(_position: vscode.Position, _regex?: RegExp | undefined): never {
-		throw new Error('Method not implemented.');
-	}
-	validateRange(_range: vscode.Range): never {
-		throw new Error('Method not implemented.');
-	}
-	validatePosition(_position: vscode.Position): never {
-		throw new Error('Method not implemented.');
-	}
-	save(): never {
-		throw new Error('Method not implemented.');
-	}
-}
-
-
 function newEngine(): MarkdownEngine {
 	return new MarkdownEngine(new class implements MarkdownContributions {
 		readonly previewScripts: vscode.Uri[] = [];