function testLineMappingDirectionAfterEvents(lines:string[], eol: string, direction:AssertDocumentLineMappingDirection, events:EditorCommon.IModelContentChangedEvent2[]): void {
		let myDocument = new PluginHostDocument(undefined, URI.file(''), lines.slice(0), eol, 'text', 1, false);
		assertDocumentLineMapping(myDocument, direction);

		myDocument._acceptEvents(events);
		assertDocumentLineMapping(myDocument, direction);
	}

	function assertDocumentLineMapping(doc:PluginHostDocument, direction:AssertDocumentLineMappingDirection): void {
		let allText = doc.getText();

		let line = 0, character = 0, previousIsCarriageReturn = false;
		for (let offset = 0; offset <= allText.length; offset++) {
			// The position coordinate system cannot express the position between \r and \n
			let	position = new Position(line, character + (previousIsCarriageReturn ? -1 : 0));

			if (direction === AssertDocumentLineMappingDirection.OffsetToPosition) {
				let actualPosition = doc.positionAt(offset);
				assert.equal(positionToStr(actualPosition), positionToStr(position), 'positionAt mismatch for offset ' + offset);
			} else {
				// The position coordinate system cannot express the position between \r and \n
				let expectedOffset = offset + (previousIsCarriageReturn ? -1 : 0);
				let actualOffset = doc.offsetAt(position);
				assert.equal(actualOffset, expectedOffset, 'offsetAt mismatch for position ' + positionToStr(position));
			}

			if (allText.charAt(offset) === '\n') {
				line++;
				character = 0;
			} else {
				character++;
			}

			previousIsCarriageReturn = (allText.charAt(offset) === '\r');
		}
	}

	test('lines', function() {

		assert.equal(doc.lineCount, 4);
		assert.throws(() => doc.lineCount = 9);

		assert.throws(() => doc.lineAt(-1));
		assert.throws(() => doc.lineAt(doc.lineCount));
		assert.throws(() => doc.lineAt(Number.MAX_VALUE));
		assert.throws(() => doc.lineAt(Number.MIN_VALUE));
		assert.throws(() => doc.lineAt(0.8));

		let line = doc.lineAt(0);
		assert.equal(line.lineNumber, 0);
		assert.equal(line.text.length, 16);
		assert.equal(line.text, 'This is line one');
		assert.equal(line.isEmptyOrWhitespace, false);
		assert.equal(line.firstNonWhitespaceCharacterIndex, 0);

		doc._acceptEvents([{
			range: { startLineNumber: 1, startColumn: 1, endLineNumber: 1, endColumn: 1 },
			text: '\t ',
			isRedoing: undefined,
			isUndoing: undefined,
			versionId: undefined,
			rangeLength: undefined,
		}]);

		// line didn't change
		assert.equal(line.text, 'This is line one');
		assert.equal(line.firstNonWhitespaceCharacterIndex, 0);

		// fetch line again
		line = doc.lineAt(0);
		assert.equal(line.text, '\t This is line one');
		assert.equal(line.firstNonWhitespaceCharacterIndex, 2);
	});

		assert.throws(() => doc.lineAt(0.8));

	function assertOffsetAt(line: number, character: number, offset: number) {
		let pos = new Position(line, character);
		let actual = doc.offsetAt(pos);
		assert.equal(actual, offset);
	}