/**
 * @license Copyright (c) 2003-2026, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-licensing-options
 */

import { toWidget, toWidgetEditable } from '../src/utils.js';

import { ClassicTestEditor } from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor.js';
import { BlockQuote } from '@ckeditor/ckeditor5-block-quote';
import { HorizontalLine } from '@ckeditor/ckeditor5-horizontal-line';
import { Image, ImageCaption } from '@ckeditor/ckeditor5-image';
import { Paragraph } from '@ckeditor/ckeditor5-paragraph';
import { Bold } from '@ckeditor/ckeditor5-basic-styles';

import { getCode, global, env } from '@ckeditor/ckeditor5-utils';
import { _getModelData, _setModelData } from '@ckeditor/ckeditor5-engine';

describe( 'Widget - vertical keyboard navigation near widgets', () => {
	let editorElement, editor, model, styleElement;
	let leftArrowDomEvtDataStub, rightArrowDomEvtDataStub, upArrowDomEvtDataStub, downArrowDomEvtDataStub;

	const imageUrl = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAGQAAAAUCAQAAADRyVAeAAAAKklEQVR42u3PAQ0AAAwCI' +
		'O0f+u/hoAHNZUJFRERERERERERERERERLYiD9N4FAFj2iK6AAAAAElFTkSuQmCC';

	beforeEach( async () => {
		editorElement = global.document.createElement( 'div' );
		global.document.body.appendChild( editorElement );

		editor = await ClassicTestEditor.create( editorElement, {
			plugins: [ Paragraph, Image, ImageCaption, HorizontalLine, BlockQuote, Bold, BlockWidgetWithNestedEditable ]
		} );

		model = editor.model;

		// The editing view must be focused because otherwise in Chrome the DOM selection will not contain
		// any ranges and jumpOverUiElement will crash (for the right arrow when shift is pressed).
		editor.editing.view.focus();

		leftArrowDomEvtDataStub = {
			keyCode: getCode( 'ArrowLeft' ),
			preventDefault: sinon.spy(),
			stopPropagation: sinon.spy(),
			domTarget: global.document.body
		};
		rightArrowDomEvtDataStub = {
			keyCode: getCode( 'ArrowRight' ),
			preventDefault: sinon.spy(),
			stopPropagation: sinon.spy(),
			domTarget: global.document.body
		};
		upArrowDomEvtDataStub = {
			keyCode: getCode( 'ArrowUp' ),
			preventDefault: sinon.spy(),
			stopPropagation: sinon.spy(),
			domTarget: global.document.body
		};
		downArrowDomEvtDataStub = {
			keyCode: getCode( 'ArrowDown' ),
			preventDefault: sinon.spy(),
			stopPropagation: sinon.spy(),
			domTarget: global.document.body
		};

		// Those tests are checking text line wrapping so forcing some sizes are needed to make those tests stable.
		// Some tests are excluded for Gecko because of differences in font rendering (text line wraps in different places).
		styleElement = global.document.createElement( 'style' );
		styleElement.appendChild( global.document.createTextNode(
			`
			* {
				font-size: 12px !important;
				font-family: serif !important;
				margin: 0 !important;
				padding: 0 !important;
				border: 0 !important
			}
			.ck.ck-editor__editable { width: 300px !important; }
			`
		) );
		global.document.querySelector( 'head' ).appendChild( styleElement );
	} );

	afterEach( async () => {
		editorElement.remove();
		styleElement.remove();
		await editor.destroy();
	} );

	it( 'should do nothing if pressed left-arrow key', () => {
		_setModelData( model,
			'<paragraph>foo</paragraph>' +
			'<paragraph>b[]ar</paragraph>' +
			'<paragraph>abc</paragraph>'
		);

		editor.editing.view.document.fire( 'keydown', leftArrowDomEvtDataStub );

		sinon.assert.notCalled( leftArrowDomEvtDataStub.preventDefault );
		sinon.assert.notCalled( leftArrowDomEvtDataStub.stopPropagation );

		expect(
			_getModelData( model ) ).to.equalMarkup(
			'<paragraph>foo</paragraph>' +
			'<paragraph>b[]ar</paragraph>' +
			'<paragraph>abc</paragraph>'
		);
	} );

	it( 'should do nothing if pressed right-arrow key', () => {
		_setModelData( model,
			'<paragraph>foo</paragraph>' +
			'<paragraph>b[]ar</paragraph>' +
			'<paragraph>abc</paragraph>'
		);

		editor.editing.view.document.fire( 'keydown', rightArrowDomEvtDataStub );

		sinon.assert.notCalled( rightArrowDomEvtDataStub.preventDefault );
		sinon.assert.notCalled( rightArrowDomEvtDataStub.stopPropagation );

		expect(
			_getModelData( model ) ).to.equalMarkup(
			'<paragraph>foo</paragraph>' +
			'<paragraph>b[]ar</paragraph>' +
			'<paragraph>abc</paragraph>'
		);
	} );

	it( 'should do nothing if shrinking non-collapsed forward selection', () => {
		_setModelData( model, '<paragraph>fo[ob]ar</paragraph>' );

		upArrowDomEvtDataStub.shiftKey = true;
		editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

		sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
		sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
	} );

	it( 'should do nothing if shrinking non-collapsed backward selection', () => {
		_setModelData( model, '<paragraph>fo[ob]ar</paragraph>', { lastRangeBackward: true } );

		downArrowDomEvtDataStub.shiftKey = true;
		editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

		sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
		sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
	} );

	describe( 'with selection inside root content editable', () => {
		describe( 'single paragraph surrounded with objects', () => {
			describe( 'collapsed selection', () => {
				beforeEach( () => {
					_setModelData( model,
						'<horizontalLine></horizontalLine>' +
						'<paragraph>foo[]bar</paragraph>' +
						'<horizontalLine></horizontalLine>'
					);
				} );

				it( 'should move caret to the position closest to object (navigating forward)', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<horizontalLine></horizontalLine>' +
						'<paragraph>foobar[]</paragraph>' +
						'<horizontalLine></horizontalLine>'
					);
				} );

				it( 'should move caret to the position closest to object (navigating backward)', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<horizontalLine></horizontalLine>' +
						'<paragraph>[]foobar</paragraph>' +
						'<horizontalLine></horizontalLine>'
					);
				} );
			} );

			describe( 'non-collapsed forward selection', () => {
				beforeEach( () => {
					_setModelData( model,
						'<horizontalLine></horizontalLine>' +
						'<paragraph>fo[ob]ar</paragraph>' +
						'<horizontalLine></horizontalLine>'
					);
				} );

				it( 'should move caret to the position closest to object (navigating forward)', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<horizontalLine></horizontalLine>' +
						'<paragraph>foobar[]</paragraph>' +
						'<horizontalLine></horizontalLine>'
					);
				} );

				it( 'should move caret to the position closest to object (navigating backward)', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<horizontalLine></horizontalLine>' +
						'<paragraph>[]foobar</paragraph>' +
						'<horizontalLine></horizontalLine>'
					);
				} );

				describe( 'with shift pressed', () => {
					it( 'should expand the selection to the position closest to object (navigating forward)', () => {
						downArrowDomEvtDataStub.shiftKey = true;
						editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

						sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<horizontalLine></horizontalLine>' +
							'<paragraph>fo[obar]</paragraph>' +
							'<horizontalLine></horizontalLine>'
						);
					} );

					it( 'should expand the selection to the position closest to object (navigating backward)', () => {
						upArrowDomEvtDataStub.shiftKey = true;
						editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

						sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<horizontalLine></horizontalLine>' +
							'<paragraph>[fo]obar</paragraph>' +
							'<horizontalLine></horizontalLine>'
						);
					} );
				} );
			} );

			describe( 'non-collapsed backward selection', () => {
				beforeEach( () => {
					_setModelData( model,
						'<horizontalLine></horizontalLine>' +
						'<paragraph>fo[ob]ar</paragraph>' +
						'<horizontalLine></horizontalLine>',
						{ lastRangeBackward: true }
					);
				} );

				it( 'should move caret to the position closest to object (navigating forward)', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<horizontalLine></horizontalLine>' +
						'<paragraph>foobar[]</paragraph>' +
						'<horizontalLine></horizontalLine>'
					);
				} );

				it( 'should move caret to the position closest to object (navigating backward)', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<horizontalLine></horizontalLine>' +
						'<paragraph>[]foobar</paragraph>' +
						'<horizontalLine></horizontalLine>'
					);
				} );

				describe( 'with shift pressed', () => {
					it( 'should not prevent default browser behavior while navigating forward', () => {
						downArrowDomEvtDataStub.shiftKey = true;
						editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

						sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<horizontalLine></horizontalLine>' +
							'<paragraph>foob[ar]</paragraph>' +
							'<horizontalLine></horizontalLine>'
						);
					} );

					it( 'should expand the selection to the position closest to object (navigating backward)', () => {
						upArrowDomEvtDataStub.shiftKey = true;
						editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

						sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<horizontalLine></horizontalLine>' +
							'<paragraph>[foob]ar</paragraph>' +
							'<horizontalLine></horizontalLine>'
						);
					} );
				} );
			} );
		} );

		describe( 'multiple paragraphs with object inside', () => {
			describe( 'caret in the first paragraph', () => {
				beforeEach( () => {
					_setModelData( model,
						'<paragraph>fo[]oo</paragraph>' +
						'<paragraph>bar</paragraph>' +
						'<horizontalLine></horizontalLine>' +
						'<paragraph>FOO</paragraph>' +
						'<paragraph>BAR</paragraph>'
					);
				} );

				it( 'should not prevent default on forward navigation', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
				} );

				it( 'should not prevent default on backward navigation', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
				} );
			} );

			describe( 'caret in the second paragraph', () => {
				beforeEach( () => {
					_setModelData( model,
						'<paragraph>foo</paragraph>' +
						'<paragraph>ba[]ar</paragraph>' +
						'<horizontalLine></horizontalLine>' +
						'<paragraph>FOO</paragraph>' +
						'<paragraph>BAR</paragraph>'
					);
				} );

				it( 'should move caret to the position closest to object on forward navigation', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<paragraph>foo</paragraph>' +
						'<paragraph>baar[]</paragraph>' +
						'<horizontalLine></horizontalLine>' +
						'<paragraph>FOO</paragraph>' +
						'<paragraph>BAR</paragraph>'
					);
				} );

				it( 'should not prevent default on backward navigation', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
				} );
			} );

			describe( 'caret in the third paragraph', () => {
				beforeEach( () => {
					_setModelData( model,
						'<paragraph>foo</paragraph>' +
						'<paragraph>bar</paragraph>' +
						'<horizontalLine></horizontalLine>' +
						'<paragraph>FO[]OO</paragraph>' +
						'<paragraph>BAR</paragraph>'
					);
				} );

				it( 'should not prevent default on forward navigation', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
				} );

				it( 'should move caret to the position closest to object on backward navigation', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<paragraph>foo</paragraph>' +
						'<paragraph>bar</paragraph>' +
						'<horizontalLine></horizontalLine>' +
						'<paragraph>[]FOOO</paragraph>' +
						'<paragraph>BAR</paragraph>'
					);
				} );
			} );

			describe( 'caret in the forth paragraph', () => {
				beforeEach( () => {
					_setModelData( model,
						'<paragraph>foo</paragraph>' +
						'<paragraph>bar</paragraph>' +
						'<horizontalLine></horizontalLine>' +
						'<paragraph>FOO</paragraph>' +
						'<paragraph>BA[]AR</paragraph>'
					);
				} );

				it( 'should not prevent default on backward navigation', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
				} );

				it( 'should not prevent default on forward navigation', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
				} );
			} );
		} );

		it( 'should integrate with the blockquote (forward navigation)', () => {
			_setModelData( model,
				'<blockQuote>' +
					'<paragraph>f[]oo</paragraph>' +
				'</blockQuote>' +
				'<horizontalLine></horizontalLine>' +
				'<paragraph>bar</paragraph>'
			);

			editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

			sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
			sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

			expect( _getModelData( model ) ).to.equalMarkup(
				'<blockQuote>' +
					'<paragraph>foo[]</paragraph>' +
				'</blockQuote>' +
				'<horizontalLine></horizontalLine>' +
				'<paragraph>bar</paragraph>'
			);
		} );

		it( 'should integrate with the blockquote (backward navigation)', () => {
			_setModelData( model,
				'<paragraph>foo</paragraph>' +
				'<horizontalLine></horizontalLine>' +
				'<blockQuote>' +
					'<paragraph>ba[]r</paragraph>' +
				'</blockQuote>'
			);

			editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

			sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
			sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

			expect( _getModelData( model ) ).to.equalMarkup(
				'<paragraph>foo</paragraph>' +
				'<horizontalLine></horizontalLine>' +
				'<blockQuote>' +
					'<paragraph>[]bar</paragraph>' +
				'</blockQuote>'
			);
		} );
	} );

	describe( 'with selection inside nested content editable', () => {
		describe( 'simple text content', () => {
			describe( 'with collapsed selection', () => {
				beforeEach( () => {
					_setModelData( model, '<widget><nested><paragraph>foo[]bar</paragraph></nested></widget>' );
				} );

				it( 'should move caret to the beginning of the nested editable content', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested><paragraph>[]foobar</paragraph></nested></widget>' );
				} );

				it( 'should move caret to the end of the nested editable content', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested><paragraph>foobar[]</paragraph></nested></widget>' );
				} );

				describe( 'when shift key is pressed', () => {
					beforeEach( () => {
						upArrowDomEvtDataStub.shiftKey = true;
						downArrowDomEvtDataStub.shiftKey = true;
					} );

					it( 'should expand selection to the beginning of the nested editable content', () => {
						editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

						sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<widget><nested><paragraph>[foo]bar</paragraph></nested></widget>'
						);
					} );

					it( 'should expand selection to the end of the nested editable content', () => {
						editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

						sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<widget><nested><paragraph>foo[bar]</paragraph></nested></widget>'
						);
					} );
				} );
			} );

			describe( 'with selection at the edge of limit element', () => {
				it( 'should do nothing if caret is at the beginning of the nested editable content', () => {
					_setModelData( model, '<widget><nested><paragraph>[]foobar</paragraph></nested></widget>' );

					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
				} );

				it( 'should do nothing if caret is at the end of the nested editable content', () => {
					_setModelData( model, '<widget><nested><paragraph>foobar[]</paragraph></nested></widget>' );

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
				} );

				it( 'should collapse selection if selection is at the beginning of the nested editable content', () => {
					_setModelData( model, '<widget><nested><paragraph>[foo]bar</paragraph></nested></widget>' );

					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested><paragraph>[]foobar</paragraph></nested></widget>' );
				} );

				it( 'should collapse selection if selection is at the end of the nested editable content', () => {
					_setModelData( model, '<widget><nested><paragraph>foo[bar]</paragraph></nested></widget>' );

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested><paragraph>foobar[]</paragraph></nested></widget>' );
				} );

				describe( 'when shift key is pressed', () => {
					beforeEach( () => {
						upArrowDomEvtDataStub.shiftKey = true;
						downArrowDomEvtDataStub.shiftKey = true;
					} );

					it( 'should collapse selection at the beginning of the nested editable content', () => {
						_setModelData( model, '<widget><nested><paragraph>[foo]bar</paragraph></nested></widget>' );

						editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

						sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<widget><nested><paragraph>[]foobar</paragraph></nested></widget>'
						);
					} );

					it( 'should do nothing when selection focus is at the beginning of the nested editable content', () => {
						_setModelData( model,
							'<widget><nested><paragraph>[foo]bar</paragraph></nested></widget>',
							{ lastRangeBackward: true }
						);

						editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

						sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
						sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
					} );

					it( 'should do nothing when selection focus is at the end of the nested editable content', () => {
						_setModelData( model, '<widget><nested><paragraph>foo[bar]</paragraph></nested></widget>' );

						editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

						sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
						sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
					} );
				} );
			} );

			describe( 'with non-collapsed forward selection', () => {
				beforeEach( () => {
					_setModelData( model, '<widget><nested><paragraph>fo[ob]ar</paragraph></nested></widget>' );
				} );

				it( 'should move caret to the beginning of the nested editable content', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested><paragraph>[]foobar</paragraph></nested></widget>' );
				} );

				it( 'should move caret to the end of the nested editable content', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested><paragraph>foobar[]</paragraph></nested></widget>' );
				} );

				describe( 'when shift key is pressed', () => {
					beforeEach( () => {
						upArrowDomEvtDataStub.shiftKey = true;
						downArrowDomEvtDataStub.shiftKey = true;
					} );

					it( 'should expand to line start on arrow up press', () => {
						editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

						sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<widget><nested><paragraph>[fo]obar</paragraph></nested></widget>'
						);
					} );

					it( 'should expand selection to the end of the nested editable content', () => {
						editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

						sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<widget><nested><paragraph>fo[obar]</paragraph></nested></widget>'
						);
					} );
				} );
			} );

			describe( 'with non-collapsed backward selection', () => {
				beforeEach( () => {
					_setModelData( model, '<widget><nested><paragraph>fo[ob]ar</paragraph></nested></widget>', {
						lastRangeBackward: true
					} );
				} );

				it( 'should move caret to the beginning of the nested editable content', () => {
					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested><paragraph>[]foobar</paragraph></nested></widget>' );
				} );

				it( 'should move caret to the end of the nested editable content', () => {
					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested><paragraph>foobar[]</paragraph></nested></widget>' );
				} );

				describe( 'when shift key is pressed', () => {
					beforeEach( () => {
						upArrowDomEvtDataStub.shiftKey = true;
						downArrowDomEvtDataStub.shiftKey = true;
					} );

					it( 'should expand selection to the beginning of the nested editable content', () => {
						editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

						sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<widget><nested><paragraph>[foob]ar</paragraph></nested></widget>'
						);
					} );

					it( 'should expand to line end on arrow down press', () => {
						editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

						sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							'<widget><nested><paragraph>foob[ar]</paragraph></nested></widget>'
						);
					} );
				} );
			} );
		} );

		describe( 'selection inside paragraph', () => {
			const text = new Array( 20 ).fill( 0 ).map( () => 'word' ).join( ' ' );

			it( 'should not prevent default browser behavior if caret is in the middle line of a text', () => {
				_setModelData( model, `<widget><nested><paragraph>${ text + '[] ' + text }</paragraph></nested></widget>` );

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
			} );

			it( 'should not prevent default browser behavior if caret is in the middle line of a text with formatting', () => {
				_setModelData( model,
					'<widget><nested><paragraph>' +
					'word word word[] word <$text bold="true">bolded</$text> word ' + text +
					'</paragraph></nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
				sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
			} );

			it( 'should move caret to beginning of nested editable content if caret is in the first line of a text', () => {
				_setModelData( model, `<widget><nested><paragraph>${ 'word[] word' + text }</paragraph></nested></widget>` );

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					`<widget><nested><paragraph>${ '[]word word' + text }</paragraph></nested></widget>`
				);
			} );

			it( 'should move caret to end of nested editable content if caret is in the last line of a text', () => {
				_setModelData( model, `<widget><nested><paragraph>${ text + 'word[] word' }</paragraph></nested></widget>` );

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					`<widget><nested><paragraph>${ text + 'word word[]' }</paragraph></nested></widget>`
				);
			} );

			describe( 'when shift key is pressed', () => {
				beforeEach( () => {
					upArrowDomEvtDataStub.shiftKey = true;
					downArrowDomEvtDataStub.shiftKey = true;
				} );

				it( 'should not prevent default browser behavior for the up arrow in the middle lines of the text', () => {
					_setModelData( model, `<widget><nested><paragraph>${ text + '[] ' + text }</paragraph></nested></widget>` );

					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
				} );

				it( 'should not prevent default browser behavior for the down arrow in the middle lines of text', () => {
					_setModelData( model, `<widget><nested><paragraph>${ text + '[] ' + text }</paragraph></nested></widget>` );

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
				} );

				it( 'should expand collapsed selection to the beginning of the nested editable content', () => {
					_setModelData( model, `<widget><nested><paragraph>${ 'word[] word' + text }</paragraph></nested></widget>` );

					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						`<widget><nested><paragraph>${ '[word] word' + text }</paragraph></nested></widget>`
					);
				} );

				it( 'should expand non-collapsed selection to the beginning of the nested editable content (up arrow)', () => {
					_setModelData( model, `<widget><nested><paragraph>${ 'word [word]' + text }</paragraph></nested></widget>` );

					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						`<widget><nested><paragraph>${ '[word ]word' + text }</paragraph></nested></widget>`
					);
				} );

				it( 'should expand not collapsed selection to the beginning of the editable content from the selection anchor', () => {
					_setModelData( model,
						`<widget><nested><paragraph>${ 'word [word]' + text }</paragraph></nested></widget>`,
						{ lastRangeBackward: true }
					);

					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						`<widget><nested><paragraph>${ '[word word]' + text }</paragraph></nested></widget>`
					);
				} );

				it( 'should expand collapsed selection to the end of the nested editable content', () => {
					_setModelData( model, `<widget><nested><paragraph>${ text + 'word[] word' }</paragraph></nested></widget>` );

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						`<widget><nested><paragraph>${ text + 'word[ word]' }</paragraph></nested></widget>`
					);
				} );

				it( 'should expand non-collapsed selection to the end of the nested editable content (down arrow)', () => {
					_setModelData( model,
						`<widget><nested><paragraph>${ text + '[word] word' }</paragraph></nested></widget>`,
						{ lastRangeBackward: true }
					);

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						`<widget><nested><paragraph>${ text + 'word[ word]' }</paragraph></nested></widget>`
					);
				} );

				it( 'should expand not collapsed selection to the end of the nested editable content from the selection anchor', () => {
					_setModelData( model, `<widget><nested><paragraph>${ text + '[word] word' }</paragraph></nested></widget>` );

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						`<widget><nested><paragraph>${ text + '[word word]' }</paragraph></nested></widget>`
					);
				} );
			} );
		} );

		if ( !env.isGecko ) {
			// These tests fails on Travis. They work correctly when started on local machine.
			// Issue is probably related to text rendering and wrapping.

			describe( 'with selection in the wrap area', () => {
				const text = new Array( 10 ).fill( 0 ).map( () => 'word' ).join( ' ' );

				it( 'should move the caret to end if the caret is after the last space in the line next to the last one', () => {
					// This is also first position in the last line.
					_setModelData( model, `<widget><nested><paragraph>${ text + ' []word word word' }</paragraph></nested></widget>` );

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						`<widget><nested><paragraph>${ text + ' word word word[]' }</paragraph></nested></widget>`
					);
				} );

				it( 'should move the caret to end if the caret is at the last space in the line next to last one', () => {
					_setModelData( model, `<widget><nested><paragraph>${ text + '[] word word word' }</paragraph></nested></widget>` );

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						`<widget><nested><paragraph>${ text + ' word word word[]' }</paragraph></nested></widget>`
					);
				} );

				it( 'should not move the caret if it\'s 2 characters before the last space in the line next to last one', () => {
					_setModelData( model,
						'<widget><nested><paragraph>' +
							text.substring( 0, text.length - 2 ) + '[]rd word word word' +
						'</paragraph></nested></widget>'
					);

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
				} );

				describe( 'when shift key is pressed', () => {
					beforeEach( () => {
						upArrowDomEvtDataStub.shiftKey = true;
						downArrowDomEvtDataStub.shiftKey = true;
					} );

					it( 'should expand collapsed selection to the end of the nested editable content', () => {
						_setModelData( model, `<widget><nested><paragraph>${ text + '[] word word word' }</paragraph></nested></widget>` );

						editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

						sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							`<widget><nested><paragraph>${ text + '[ word word word]' }</paragraph></nested></widget>`
						);
					} );

					it( 'should expand not collapsed selection to the end of the nested editable content from the selection anchor', () => {
						_setModelData( model, `<widget><nested><paragraph>${ text + '[ word] word word' }</paragraph></nested></widget>` );

						editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

						sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
						sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

						expect( _getModelData( model ) ).to.equalMarkup(
							`<widget><nested><paragraph>${ text + '[ word word word]' }</paragraph></nested></widget>`
						);
					} );
				} );
			} );
		}

		describe( 'with multiple paragraphs of text', () => {
			const text = new Array( 100 ).fill( 0 ).map( () => 'word' ).join( ' ' );

			it( 'should not prevent default browser behavior if caret is in the middle of a line of text', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<paragraph>${ text }[]${ text }</paragraph>` +
						'<paragraph>foobar</paragraph>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
			} );

			it( 'should move the caret to the beginning of a nested editable content if the caret is in the first line of text', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<paragraph>word[]${ text }</paragraph>` +
						'<paragraph>foobar</paragraph>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
						`<paragraph>[]word${ text }</paragraph>` +
						'<paragraph>foobar</paragraph>' +
					'</nested></widget>'
				);
			} );

			it( 'should not move the caret to the end of a nested editable content if the caret is not in the last line of text', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<paragraph>${ text }word []word</paragraph>` +
						'<paragraph>foobar</paragraph>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
				sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
			} );

			it( 'should move the caret to end of a nested editable content if the caret is in the last line of text', () => {
				_setModelData( model,
					'<widget><nested>' +
						'<paragraph>foobar</paragraph>' +
						`<paragraph>${ text }word []word</paragraph>` +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
						'<paragraph>foobar</paragraph>' +
						`<paragraph>${ text }word word[]</paragraph>` +
					'</nested></widget>'
				);
			} );

			describe( 'when shift key is pressed', () => {
				beforeEach( () => {
					upArrowDomEvtDataStub.shiftKey = true;
					downArrowDomEvtDataStub.shiftKey = true;
				} );

				it( 'should expand selection to the beginning of the nested editable content', () => {
					_setModelData( model,
						'<widget><nested>' +
							`<paragraph>word[] ${ text }</paragraph>` +
							`<paragraph>${ text }</paragraph>` +
						'</nested></widget>'
					);

					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<widget><nested>' +
							`<paragraph>[word] ${ text }</paragraph>` +
							`<paragraph>${ text }</paragraph>` +
						'</nested></widget>'
					);
				} );

				it( 'should expand selection to the end of the nested editable content', () => {
					_setModelData( model,
						'<widget><nested>' +
							`<paragraph>${ text }</paragraph>` +
							`<paragraph>${ text } []word</paragraph>` +
						'</nested></widget>'
					);

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<widget><nested>' +
							`<paragraph>${ text }</paragraph>` +
							`<paragraph>${ text } [word]</paragraph>` +
						'</nested></widget>'
					);
				} );
			} );
		} );

		describe( 'with horizontal line widget', () => {
			const text = new Array( 100 ).fill( 0 ).map( () => 'word' ).join( ' ' );

			it( 'should not navigate if the caret is in the middle line of text', () => {
				_setModelData( model,
					'<widget><nested>' +
						'<horizontalLine></horizontalLine>' +
						`<paragraph>${ text }[]${ text }</paragraph>` +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
			} );

			it( 'should move the caret to the beginning of the editable non-object content if it\'s is in the first line of text', () => {
				_setModelData( model,
					'<widget><nested>' +
						'<horizontalLine></horizontalLine>' +
						`<paragraph>word[] ${ text }</paragraph>` +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
						'<horizontalLine></horizontalLine>' +
						`<paragraph>[]word ${ text }</paragraph>` +
					'</nested></widget>'
				);
			} );

			it( 'should move the caret to the end of the editable non-object content if the caret is in the last line of text', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<paragraph>${ text } word []word</paragraph>` +
						'<horizontalLine></horizontalLine>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
						`<paragraph>${ text } word word[]</paragraph>` +
						'<horizontalLine></horizontalLine>' +
					'</nested></widget>'
				);
			} );

			it( 'should not move the caret to the end of nested editable content if widget is selected in middle of that content', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<paragraph>${ text }</paragraph>` +
						'[<horizontalLine></horizontalLine>]' +
						`<paragraph>${ text }</paragraph>` +
						'<horizontalLine></horizontalLine>' +
					'</nested></widget>'
				);

				// Note: Two keydowns are necessary because the first one is handled by the WidgetTypeAround plugin
				// to activate the "fake caret".
				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );
				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
						`<paragraph>${ text }</paragraph>` +
						'<horizontalLine></horizontalLine>' +
						`<paragraph>[]${ text }</paragraph>` +
						'<horizontalLine></horizontalLine>' +
					'</nested></widget>'
				);
			} );

			it( 'should not move the caret to the end of nested editable content if widget is next to the selection', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<paragraph>${ text }</paragraph>` +
						'[]<horizontalLine></horizontalLine>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
						`<paragraph>${ text }</paragraph>` +
						'[<horizontalLine></horizontalLine>]' +
					'</nested></widget>'
				);
			} );

			describe( 'when shift key is pressed', () => {
				beforeEach( () => {
					upArrowDomEvtDataStub.shiftKey = true;
					downArrowDomEvtDataStub.shiftKey = true;
				} );

				it( 'should expand selection to the beginning of the nested editable content', () => {
					_setModelData( model,
						'<widget><nested>' +
							'<horizontalLine></horizontalLine>' +
							'<paragraph>foo[]bar</paragraph>' +
						'</nested></widget>'
					);

					editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

					sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<widget><nested>' +
							'<horizontalLine></horizontalLine>' +
							'<paragraph>[foo]bar</paragraph>' +
						'</nested></widget>'
					);
				} );

				it( 'should expand selection to the end of the nested editable content', () => {
					_setModelData( model,
						'<widget><nested>' +
							'<paragraph>foo[]bar</paragraph>' +
							'<horizontalLine></horizontalLine>' +
						'</nested></widget>'
					);

					editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

					sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
					sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

					expect( _getModelData( model ) ).to.equalMarkup(
						'<widget><nested>' +
							'<paragraph>foo[bar]</paragraph>' +
							'<horizontalLine></horizontalLine>' +
						'</nested></widget>'
					);
				} );
			} );
		} );

		describe( 'contains image widget with caption and selection inside the caption', () => {
			it( 'should move caret to the closest limit boundary', () => {
				_setModelData( model,
					'<widget><nested>' +
						'<paragraph>foo</paragraph>' +
						`<imageBlock src="${ imageUrl }"><caption>bar[]baz</caption></imageBlock>` +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup( '<widget><nested>' +
					'<paragraph>foo</paragraph>' +
					`<imageBlock src="${ imageUrl }"><caption>[]barbaz</caption></imageBlock>` +
					'</nested></widget>'
				);
			} );

			it( 'should not prevent default browser behavior when caret at the beginning of nested editable', () => {
				_setModelData( model,
					'<widget><nested>' +
						'<paragraph>foo</paragraph>' +
						`<imageBlock src="${ imageUrl }"><caption>[]barbaz</caption></imageBlock>` +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
			} );

			it( 'should move the caret to the first position of the image caption', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<imageBlock src="${ imageUrl }"><caption>bar[]baz</caption></imageBlock>` +
						'<paragraph>foo</paragraph>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

				sinon.assert.calledOnce( upArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( upArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
						`<imageBlock src="${ imageUrl }"><caption>[]barbaz</caption></imageBlock>` +
						'<paragraph>foo</paragraph>' +
					'</nested></widget>'
				);
			} );

			it( 'should move caret to the end of image caption', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<imageBlock src="${ imageUrl }"><caption>bar[]baz</caption></imageBlock>` +
						'<paragraph>foo</paragraph>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
					`<imageBlock src="${ imageUrl }"><caption>barbaz[]</caption></imageBlock>` +
					'<paragraph>foo</paragraph>' +
					'</nested></widget>'
				);
			} );

			it( 'should move caret to the end of image caption when caret is on the position next to the last one', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<imageBlock src="${ imageUrl }"><caption>barba[]z</caption></imageBlock>` +
						'<paragraph>foo</paragraph>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				sinon.assert.calledOnce( downArrowDomEvtDataStub.preventDefault );
				sinon.assert.calledOnce( downArrowDomEvtDataStub.stopPropagation );

				expect( _getModelData( model ) ).to.equalMarkup(
					'<widget><nested>' +
					`<imageBlock src="${ imageUrl }"><caption>barbaz[]</caption></imageBlock>` +
					'<paragraph>foo</paragraph>' +
					'</nested></widget>'
				);
			} );

			it( 'should not prevent default browser behavior when caret inside image caption when followed by a paragraph', () => {
				_setModelData( model,
					'<widget><nested>' +
						`<imageBlock src="${ imageUrl }"><caption>barbaz[]</caption></imageBlock>` +
						'<paragraph>foo</paragraph>' +
					'</nested></widget>'
				);

				editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

				sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
				sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
			} );
		} );
	} );

	describe( 'with selection on nested editable', () => {
		it( 'should not move the selection if there is no selectable in the limit (up arrow)', () => {
			_setModelData( model,
				'<widget>' +
					'<nested>' +
						'<paragraph>foo</paragraph>' +
					'</nested>' +
					'[<nested>' +
						'<paragraph>bar</paragraph>' +
					'</nested>]' +
				'</widget>'
			);

			editor.editing.view.document.fire( 'keydown', upArrowDomEvtDataStub );

			expect( _getModelData( model ) ).to.equalMarkup(
				'<widget>' +
					'<nested>' +
						'<paragraph>foo</paragraph>' +
					'</nested>' +
					'[<nested>' +
						'<paragraph>bar</paragraph>' +
					'</nested>]' +
				'</widget>'
			);

			sinon.assert.notCalled( upArrowDomEvtDataStub.preventDefault );
			sinon.assert.notCalled( upArrowDomEvtDataStub.stopPropagation );
		} );

		it( 'should not move the selection if there is no selectable in the limit (down arrow)', () => {
			_setModelData( model,
				'<widget>' +
					'[<nested>' +
						'<paragraph>foo</paragraph>' +
					'</nested>]' +
					'<nested>' +
						'<paragraph>bar</paragraph>' +
					'</nested>' +
				'</widget>'
			);

			editor.editing.view.document.fire( 'keydown', downArrowDomEvtDataStub );

			expect( _getModelData( model ) ).to.equalMarkup(
				'<widget>' +
					'[<nested>' +
						'<paragraph>foo</paragraph>' +
					'</nested>]' +
					'<nested>' +
						'<paragraph>bar</paragraph>' +
					'</nested>' +
				'</widget>'
			);

			sinon.assert.notCalled( downArrowDomEvtDataStub.preventDefault );
			sinon.assert.notCalled( downArrowDomEvtDataStub.stopPropagation );
		} );
	} );

	function BlockWidgetWithNestedEditable( editor ) {
		const model = editor.model;

		model.schema.register( 'widget', {
			allowWhere: '$block',
			isObject: true,
			isBlock: true
		} );

		model.schema.register( 'nested', {
			allowIn: 'widget',
			isLimit: true,
			isSelectable: true
		} );

		model.schema.extend( '$block', {
			allowIn: 'nested'
		} );

		editor.conversion.for( 'dataDowncast' )
			.elementToElement( {
				model: 'widget',
				view: ( modelItem, { writer } ) => {
					return writer.createContainerElement( 'figure' );
				}
			} )
			.elementToElement( {
				model: 'nested',
				view: ( modelItem, { writer } ) => {
					return writer.createContainerElement( 'figcaption' );
				}
			} );

		editor.conversion.for( 'editingDowncast' )
			.elementToElement( {
				model: 'widget',
				view: ( modelItem, { writer } ) => {
					const div = writer.createContainerElement( 'figure' );

					return toWidget( div, writer, { label: 'widget label' } );
				}
			} )
			.elementToElement( {
				model: 'nested',
				view: ( modelItem, { writer } ) => {
					const nested = writer.createEditableElement( 'figcaption' );

					return toWidgetEditable( nested, writer );
				}
			} );

		editor.conversion.for( 'upcast' )
			.elementToElement( {
				view: 'figure',
				model: 'widget'
			} )
			.elementToElement( {
				view: 'figcaption',
				model: 'nested'
			} );
	}
} );
