packages/compiler/test/ml_parser/html_parser_spec.ts - main - githubmirror/angular

packages/compiler/test/ml_parser/html_parser_spec.ts
2 120 строк79 KB
Kristiyan Kostadinov
fix(core): ignore processing instruction syntax in templates
15 июл 2026, 21:57
15 июл 2026, 21:5768ac204
/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.dev/license
 */

import * as html from '../../src/ml_parser/ast';
import {HtmlParser} from '../../src/ml_parser/html_parser';
import {TokenizeOptions} from '../../src/ml_parser/lexer';
import {ParseTreeResult, TreeError} from '../../src/ml_parser/parser';
import {ParseError} from '../../src/parse_util';

import {
  humanizeDom,
  humanizeDomSourceSpans,
  humanizeLineColumn,
  humanizeNodes,
} from './ast_spec_utils';

describe('HtmlParser', () => {
  let parser: HtmlParser;

  beforeEach(() => {
    parser = new HtmlParser();
  });

  describe('parse', () => {
    describe('text nodes', () => {
      it('should parse root level text nodes', () => {
        expect(humanizeDom(parser.parse('a', 'TestComp'))).toEqual([[html.Text, 'a', 0, ['a']]]);
      });

      it('should parse text nodes inside regular elements', () => {
        expect(humanizeDom(parser.parse('<div>a</div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Text, 'a', 1, ['a']],
        ]);
      });

      it('should parse text nodes inside <ng-template> elements', () => {
        expect(humanizeDom(parser.parse('<ng-template>a</ng-template>', 'TestComp'))).toEqual([
          [html.Element, 'ng-template', 0],
          [html.Text, 'a', 1, ['a']],
        ]);
      });

      it('should parse CDATA', () => {
        expect(humanizeDom(parser.parse('<![CDATA[text]]>', 'TestComp'))).toEqual([
          [html.Text, 'text', 0, ['text']],
        ]);
      });

      it('should parse text nodes with HTML entities (5+ hex digits)', () => {
        // Test with 🛈 (U+1F6C8 - Circled Information Source)
        expect(humanizeDom(parser.parse('<div>&#x1F6C8;</div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Text, '\u{1F6C8}', 1, [''], ['\u{1F6C8}', '&#x1F6C8;'], ['']],
        ]);
      });

      it('should parse text nodes with decimal HTML entities (5+ digits)', () => {
        // Test with 🛈 (U+1F6C8 - Circled Information Source) as decimal 128712
        expect(humanizeDom(parser.parse('<div>&#128712;</div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Text, '\u{1F6C8}', 1, [''], ['\u{1F6C8}', '&#128712;'], ['']],
        ]);
      });

      it('should parse named HTML entities containing digits', () => {
        expect(humanizeDom(parser.parse('<div>&sup1;</div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Text, '\u00B9', 1, [''], ['\u00B9', '&sup1;'], ['']],
        ]);
        expect(humanizeDom(parser.parse('<div>&frac12;</div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Text, '\u00BD', 1, [''], ['\u00BD', '&frac12;'], ['']],
        ]);
      });

      it('should normalize line endings within CDATA', () => {
        const parsed = parser.parse('<![CDATA[ line 1 \r\n line 2 ]]>', 'TestComp');
        expect(humanizeDom(parsed)).toEqual([
          [html.Text, ' line 1 \n line 2 ', 0, [' line 1 \n line 2 ']],
        ]);
        expect(parsed.errors).toEqual([]);
      });
    });

    describe('elements', () => {
      it('should parse root level elements', () => {
        expect(humanizeDom(parser.parse('<div></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
        ]);
      });

      it('should parse elements inside of regular elements', () => {
        expect(humanizeDom(parser.parse('<div><span></span></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Element, 'span', 1],
        ]);
      });

      it('should parse elements inside  <ng-template> elements', () => {
        expect(
          humanizeDom(parser.parse('<ng-template><span></span></ng-template>', 'TestComp')),
        ).toEqual([
          [html.Element, 'ng-template', 0],
          [html.Element, 'span', 1],
        ]);
      });

      it('should support void elements', () => {
        expect(
          humanizeDom(parser.parse('<link rel="author license" href="/about">', 'TestComp')),
        ).toEqual([
          [html.Element, 'link', 0],
          [html.Attribute, 'rel', 'author license', ['author license']],
          [html.Attribute, 'href', '/about', ['/about']],
        ]);
      });

      it('should indicate whether an element is void', () => {
        const nodes = parser.parse('<input><div></div>', 'TestComp').rootNodes as html.Element[];
        expect(nodes[0].name).toBe('input');
        expect(nodes[0].isVoid).toBe(true);
        expect(nodes[1].name).toBe('div');
        expect(nodes[1].isVoid).toBe(false);
      });

      it('should not error on void elements from HTML5 spec', () => {
        // https://html.spec.whatwg.org/multipage/syntax.html#syntax-elements without:
        // <base> - it can be present in head only
        // <meta> - it can be present in head only
        // <command> - obsolete
        // <keygen> - obsolete
        [
          '<map><area></map>',
          '<div><br></div>',
          '<colgroup><col></colgroup>',
          '<div><embed></div>',
          '<div><hr></div>',
          '<div><img></div>',
          '<div><input></div>',
          '<object><param>/<object>',
          '<audio><source></audio>',
          '<audio><track></audio>',
          '<p><wbr></p>',
        ].forEach((html) => {
          expect(parser.parse(html, 'TestComp').errors).toEqual([]);
        });
      });

      it('should close void elements on text nodes', () => {
        expect(humanizeDom(parser.parse('<p>before<br>after</p>', 'TestComp'))).toEqual([
          [html.Element, 'p', 0],
          [html.Text, 'before', 1, ['before']],
          [html.Element, 'br', 1],
          [html.Text, 'after', 1, ['after']],
        ]);
      });

      it('should support optional end tags', () => {
        expect(humanizeDom(parser.parse('<div><p>1<p>2</div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Element, 'p', 1],
          [html.Text, '1', 2, ['1']],
          [html.Element, 'p', 1],
          [html.Text, '2', 2, ['2']],
        ]);
      });

      it('should support nested elements', () => {
        expect(
          humanizeDom(parser.parse('<ul><li><ul><li></li></ul></li></ul>', 'TestComp')),
        ).toEqual([
          [html.Element, 'ul', 0],
          [html.Element, 'li', 1],
          [html.Element, 'ul', 2],
          [html.Element, 'li', 3],
        ]);
      });

      /**
       * Certain elements (like <tr> or <col>) require parent elements of a certain type (ex. <tr>
       * can only be inside <tbody> / <thead>). The Angular HTML parser doesn't validate those
       * HTML compliancy rules as "problematic" elements can be projected - in such case HTML (as
       * written in an Angular template) might be "invalid" (spec-wise) but the resulting DOM will
       * still be correct.
       */
      it('should not wraps elements in a required parent', () => {
        expect(humanizeDom(parser.parse('<div><tr></tr></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Element, 'tr', 1],
        ]);
      });

      it('should support explicit namespace', () => {
        expect(humanizeDom(parser.parse('<myns:div></myns:div>', 'TestComp'))).toEqual([
          [html.Element, ':myns:div', 0],
        ]);
      });

      it('should support implicit namespace', () => {
        expect(humanizeDom(parser.parse('<svg></svg>', 'TestComp'))).toEqual([
          [html.Element, ':svg:svg', 0],
        ]);
      });

      it('should propagate the namespace', () => {
        expect(humanizeDom(parser.parse('<myns:div><p></p></myns:div>', 'TestComp'))).toEqual([
          [html.Element, ':myns:div', 0],
          [html.Element, ':myns:p', 1],
        ]);
      });

      it('should match closing tags case sensitive', () => {
        const errors = parser.parse('<DiV><P></p></dIv>', 'TestComp').errors;
        expect(errors.length).toEqual(2);
        expect(humanizeErrors(errors)).toEqual([
          [
            'p',
            'Unexpected closing tag "p". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags',
            '0:8',
          ],
          [
            'dIv',
            'Unexpected closing tag "dIv". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags',
            '0:12',
          ],
        ]);
      });

      it('should support self closing void elements', () => {
        expect(humanizeDom(parser.parse('<input />', 'TestComp'))).toEqual([
          [html.Element, 'input', 0, '#selfClosing'],
        ]);
      });

      it('should support self closing foreign elements', () => {
        expect(humanizeDom(parser.parse('<math />', 'TestComp'))).toEqual([
          [html.Element, ':math:math', 0, '#selfClosing'],
        ]);
      });

      it('should ignore LF immediately after textarea, pre and listing', () => {
        expect(
          humanizeDom(
            parser.parse(
              '<p>\n</p><textarea>\n</textarea><pre>\n\n</pre><listing>\n\n</listing>',
              'TestComp',
            ),
          ),
        ).toEqual([
          [html.Element, 'p', 0],
          [html.Text, '\n', 1, ['\n']],
          [html.Element, 'textarea', 0],
          [html.Element, 'pre', 0],
          [html.Text, '\n', 1, ['\n']],
          [html.Element, 'listing', 0],
          [html.Text, '\n', 1, ['\n']],
        ]);
      });

      it('should normalize line endings in text', () => {
        let parsed: ParseTreeResult;
        parsed = parser.parse('<title> line 1 \r\n line 2 </title>', 'TestComp');
        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'title', 0],
          [html.Text, ' line 1 \n line 2 ', 1, [' line 1 \n line 2 ']],
        ]);
        expect(parsed.errors).toEqual([]);

        parsed = parser.parse('<script> line 1 \r\n line 2 </script>', 'TestComp');
        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'script', 0],
          [html.Text, ' line 1 \n line 2 ', 1, [' line 1 \n line 2 ']],
        ]);
        expect(parsed.errors).toEqual([]);

        parsed = parser.parse('<div> line 1 \r\n line 2 </div>', 'TestComp');
        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'div', 0],
          [html.Text, ' line 1 \n line 2 ', 1, [' line 1 \n line 2 ']],
        ]);
        expect(parsed.errors).toEqual([]);

        parsed = parser.parse('<span> line 1 \r\n line 2 </span>', 'TestComp');
        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'span', 0],
          [html.Text, ' line 1 \n line 2 ', 1, [' line 1 \n line 2 ']],
        ]);
        expect(parsed.errors).toEqual([]);
      });

      it('should parse element with JavaScript keyword tag name', () => {
        expect(humanizeDom(parser.parse('<constructor></constructor>', 'TestComp'))).toEqual([
          [html.Element, 'constructor', 0],
        ]);
      });
    });

    describe('attributes', () => {
      it('should parse attributes on regular elements case sensitive', () => {
        expect(humanizeDom(parser.parse('<div kEy="v" key2=v2></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'kEy', 'v', ['v']],
          [html.Attribute, 'key2', 'v2', ['v2']],
        ]);
      });

      it('should parse attributes containing interpolation', () => {
        expect(humanizeDom(parser.parse('<div foo="1{{message}}2"></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'foo', '1{{message}}2', ['1'], ['{{', 'message', '}}'], ['2']],
        ]);
      });

      it('should parse attributes containing unquoted interpolation', () => {
        expect(humanizeDom(parser.parse('<div foo={{message}}></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'foo', '{{message}}', [''], ['{{', 'message', '}}'], ['']],
        ]);
      });

      it('should parse bound inputs with expressions containing newlines', () => {
        expect(
          humanizeDom(
            parser.parse(
              `<app-component\n                        [attr]="[\n                        {text: 'some text',url:'//www.google.com'},\n                        {text:'other text',url:'//www.google.com'}]">` +
                `</app-component>`,
              'TestComp',
            ),
          ),
        ).toEqual([
          [html.Element, 'app-component', 0],
          [
            html.Attribute,
            '[attr]',
            `[\n                        {text: 'some text',url:'//www.google.com'},\n                        {text:'other text',url:'//www.google.com'}]`,
            [
              `[\n                        {text: 'some text',url:'//www.google.com'},\n                        {text:'other text',url:'//www.google.com'}]`,
            ],
          ],
        ]);
      });

      it('should parse attributes containing encoded entities', () => {
        expect(humanizeDom(parser.parse('<div foo="&amp;"></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'foo', '&', [''], ['&', '&amp;'], ['']],
        ]);
      });

      it('should parse attributes containing encoded entities (5+ hex digits)', () => {
        // Test with 🛈 (U+1F6C8 - Circled Information Source)
        expect(humanizeDom(parser.parse('<div foo="&#x1F6C8;"></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'foo', '\u{1F6C8}', [''], ['\u{1F6C8}', '&#x1F6C8;'], ['']],
        ]);
      });

      it('should parse attributes containing encoded decimal entities (5+ digits)', () => {
        // Test with 🛈 (U+1F6C8 - Circled Information Source) as decimal 128712
        expect(humanizeDom(parser.parse('<div foo="&#128712;"></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'foo', '\u{1F6C8}', [''], ['\u{1F6C8}', '&#128712;'], ['']],
        ]);
      });

      it('should decode HTML entities in interpolated attributes', () => {
        // Note that the detail of decoding corner-cases is tested in the
        // "should decode HTML entities in interpolations" spec.
        expect(
          humanizeDomSourceSpans(parser.parse('<div foo="{{&amp;}}"></div>', 'TestComp')),
        ).toEqual([
          [
            html.Element,
            'div',
            0,
            '<div foo="{{&amp;}}"></div>',
            '<div foo="{{&amp;}}">',
            '</div>',
          ],
          [html.Attribute, 'foo', '{{&}}', [''], ['{{', '&amp;', '}}'], [''], 'foo="{{&amp;}}"'],
        ]);
      });

      it('should normalize line endings within attribute values', () => {
        const result = parser.parse('<div key="  \r\n line 1 \r\n   line 2  "></div>', 'TestComp');
        expect(humanizeDom(result)).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'key', '  \n line 1 \n   line 2  ', ['  \n line 1 \n   line 2  ']],
        ]);
        expect(result.errors).toEqual([]);
      });

      it('should parse attributes without values', () => {
        expect(humanizeDom(parser.parse('<div k></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'k', ''],
        ]);
      });

      it('should parse attributes on svg elements case sensitive', () => {
        expect(humanizeDom(parser.parse('<svg viewBox="0"></svg>', 'TestComp'))).toEqual([
          [html.Element, ':svg:svg', 0],
          [html.Attribute, 'viewBox', '0', ['0']],
        ]);
      });

      it('should parse attributes on <ng-template> elements', () => {
        expect(humanizeDom(parser.parse('<ng-template k="v"></ng-template>', 'TestComp'))).toEqual([
          [html.Element, 'ng-template', 0],
          [html.Attribute, 'k', 'v', ['v']],
        ]);
      });

      it('should support namespace', () => {
        expect(humanizeDom(parser.parse('<svg:use xlink:href="Port" />', 'TestComp'))).toEqual([
          [html.Element, ':svg:use', 0, '#selfClosing'],
          [html.Attribute, ':xlink:href', 'Port', ['Port']],
        ]);
      });

      it('should support a prematurely terminated interpolation in attribute', () => {
        const {errors, rootNodes} = parser.parse('<div p="{{ abc"><span></span>', 'TestComp');
        expect(humanizeNodes(rootNodes, true)).toEqual([
          [html.Element, 'div', 0, '<div p="{{ abc">', '<div p="{{ abc">', null],
          [html.Attribute, 'p', '{{ abc', [''], ['{{', ' abc'], [''], 'p="{{ abc"'],
          [html.Element, 'span', 1, '<span></span>', '<span>', '</span>'],
        ]);
        expect(humanizeErrors(errors)).toEqual([]);
      });

      describe('animate instructions', () => {
        it('should parse animate.enter as a static attribute', () => {
          expect(humanizeDom(parser.parse(`<div animate.enter="foo"></div>`, 'TestComp'))).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, 'animate.enter', 'foo', ['foo']],
          ]);
        });

        it('should parse animate.leave as a static attribute', () => {
          expect(humanizeDom(parser.parse(`<div animate.leave="bar"></div>`, 'TestComp'))).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, 'animate.leave', 'bar', ['bar']],
          ]);
        });

        it('should not parse any other animate prefix binding as animate.leave', () => {
          expect(humanizeDom(parser.parse(`<div animateAbc="bar"></div>`, 'TestComp'))).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, 'animateAbc', 'bar', ['bar']],
          ]);
        });

        it('should parse both animate.enter and animate.leave as static attributes', () => {
          expect(
            humanizeDom(
              parser.parse(`<div animate.enter="foo" animate.leave="bar"></div>`, 'TestComp'),
            ),
          ).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, 'animate.enter', 'foo', ['foo']],
            [html.Attribute, 'animate.leave', 'bar', ['bar']],
          ]);
        });

        it('should parse animate.enter as a property binding', () => {
          expect(
            humanizeDom(parser.parse(`<div [animate.enter]="'foo'"></div>`, 'TestComp')),
          ).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, '[animate.enter]', `'foo'`, [`'foo'`]],
          ]);
        });

        it('should parse animate.leave as a property binding with a string array', () => {
          expect(
            humanizeDom(parser.parse(`<div [animate.leave]="['bar', 'baz']"></div>`, 'TestComp')),
          ).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, '[animate.leave]', `['bar', 'baz']`, [`['bar', 'baz']`]],
          ]);
        });

        it('should parse animate.enter as an event binding', () => {
          expect(
            humanizeDom(
              parser.parse(`<div (animate.enter)="onAnimation($event)"></div>`, 'TestComp'),
            ),
          ).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, '(animate.enter)', 'onAnimation($event)', ['onAnimation($event)']],
          ]);
        });

        it('should parse animate.leave as an event binding', () => {
          expect(
            humanizeDom(
              parser.parse(`<div (animate.leave)="onAnimation($event)"></div>`, 'TestComp'),
            ),
          ).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, '(animate.leave)', 'onAnimation($event)', ['onAnimation($event)']],
          ]);
        });

        it('should not parse other animate prefixes as animate.leave', () => {
          expect(
            humanizeDom(parser.parse(`<div (animateXYZ)="onAnimation()"></div>`, 'TestComp')),
          ).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, '(animateXYZ)', 'onAnimation()', ['onAnimation()']],
          ]);
        });

        it('should parse a combination of animate property and event bindings', () => {
          expect(
            humanizeDom(
              parser.parse(
                `<div [animate.enter]="'foo'" (animate.leave)="onAnimation($event)"></div>`,
                'TestComp',
              ),
            ),
          ).toEqual([
            [html.Element, 'div', 0],
            [html.Attribute, '[animate.enter]', `'foo'`, [`'foo'`]],
            [html.Attribute, '(animate.leave)', 'onAnimation($event)', ['onAnimation($event)']],
          ]);
        });
      });

      it('should parse square-bracketed attributes more permissively', () => {
        expect(
          humanizeDom(
            parser.parse(
              `<foo [class.text-primary/80]="expr" ` +
                `[class.data-active:text-green-300/80]="expr2" ` +
                `[class.data-[size='large']:p-8] = "expr3" some-attr/>`,
              'TestComp',
            ),
          ),
        ).toEqual([
          [html.Element, 'foo', 0, '#selfClosing'],
          [html.Attribute, '[class.text-primary/80]', 'expr', ['expr']],
          [html.Attribute, '[class.data-active:text-green-300/80]', 'expr2', ['expr2']],
          [html.Attribute, "[class.data-[size='large']:p-8]", 'expr3', ['expr3']],
          [html.Attribute, 'some-attr', ''],
        ]);
      });
    });

    describe('comments', () => {
      it('should preserve comments', () => {
        expect(humanizeDom(parser.parse('<!-- comment --><div></div>', 'TestComp'))).toEqual([
          [html.Comment, 'comment', 0],
          [html.Element, 'div', 0],
        ]);
      });
      it('should normalize line endings within comments', () => {
        expect(humanizeDom(parser.parse('<!-- line 1 \r\n line 2 -->', 'TestComp'))).toEqual([
          [html.Comment, 'line 1 \n line 2', 0],
        ]);
      });
    });

    describe('expansion forms', () => {
      it('should parse out expansion forms (with multiple cases)', () => {
        const parsed = parser.parse(
          `<div>before{messages.length, plural, =0 {You have <b>no</b> messages} =1 {One {{message}}}}after</div>`,
          'TestComp',
          {tokenizeExpansionForms: true},
        );

        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'div', 0],
          [html.Text, 'before', 1, ['before']],
          [html.Expansion, 'messages.length', 'plural', 1],
          [html.ExpansionCase, '=0', 2],
          [html.ExpansionCase, '=1', 2],
          [html.Text, 'after', 1, ['after']],
        ]);
        const cases = (<any>parsed.rootNodes[0]).children[1].cases;

        expect(humanizeDom(new ParseTreeResult(cases[0].expression, []))).toEqual([
          [html.Text, 'You have ', 0, ['You have ']],
          [html.Element, 'b', 0],
          [html.Text, 'no', 1, ['no']],
          [html.Text, ' messages', 0, [' messages']],
        ]);

        expect(humanizeDom(new ParseTreeResult(cases[1].expression, []))).toEqual([
          [html.Text, 'One {{message}}', 0, ['One '], ['{{', 'message', '}}'], ['']],
        ]);
      });

      it('should normalize line-endings in expansion forms in inline templates if `i18nNormalizeLineEndingsInICUs` is true', () => {
        const parsed = parser.parse(
          `<div>\r\n` +
            `  {\r\n` +
            `    messages.length,\r\n` +
            `    plural,\r\n` +
            `    =0 {You have \r\nno\r\n messages}\r\n` +
            `    =1 {One {{message}}}}\r\n` +
            `</div>`,
          'TestComp',
          {
            tokenizeExpansionForms: true,
            escapedString: true,
            i18nNormalizeLineEndingsInICUs: true,
          },
        );

        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'div', 0],
          [html.Text, '\n  ', 1, ['\n  ']],
          [html.Expansion, '\n    messages.length', 'plural', 1],
          [html.ExpansionCase, '=0', 2],
          [html.ExpansionCase, '=1', 2],
          [html.Text, '\n', 1, ['\n']],
        ]);
        const cases = (<any>parsed.rootNodes[0]).children[1].cases;

        expect(humanizeDom(new ParseTreeResult(cases[0].expression, []))).toEqual([
          [html.Text, 'You have \nno\n messages', 0, ['You have \nno\n messages']],
        ]);

        expect(humanizeDom(new ParseTreeResult(cases[1].expression, []))).toEqual([
          [html.Text, 'One {{message}}', 0, ['One '], ['{{', 'message', '}}'], ['']],
        ]);

        expect(parsed.errors).toEqual([]);
      });

      it('should not normalize line-endings in ICU expressions in external templates when `i18nNormalizeLineEndingsInICUs` is not set', () => {
        const parsed = parser.parse(
          `<div>\r\n` +
            `  {\r\n` +
            `    messages.length,\r\n` +
            `    plural,\r\n` +
            `    =0 {You have \r\nno\r\n messages}\r\n` +
            `    =1 {One {{message}}}}\r\n` +
            `</div>`,
          'TestComp',
          {tokenizeExpansionForms: true, escapedString: true},
        );

        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'div', 0],
          [html.Text, '\n  ', 1, ['\n  ']],
          [html.Expansion, '\r\n    messages.length', 'plural', 1],
          [html.ExpansionCase, '=0', 2],
          [html.ExpansionCase, '=1', 2],
          [html.Text, '\n', 1, ['\n']],
        ]);
        const cases = (<any>parsed.rootNodes[0]).children[1].cases;

        expect(humanizeDom(new ParseTreeResult(cases[0].expression, []))).toEqual([
          [html.Text, 'You have \nno\n messages', 0, ['You have \nno\n messages']],
        ]);

        expect(humanizeDom(new ParseTreeResult(cases[1].expression, []))).toEqual([
          [html.Text, 'One {{message}}', 0, ['One '], ['{{', 'message', '}}'], ['']],
        ]);

        expect(parsed.errors).toEqual([]);
      });

      it('should normalize line-endings in expansion forms in external templates if `i18nNormalizeLineEndingsInICUs` is true', () => {
        const parsed = parser.parse(
          `<div>\r\n` +
            `  {\r\n` +
            `    messages.length,\r\n` +
            `    plural,\r\n` +
            `    =0 {You have \r\nno\r\n messages}\r\n` +
            `    =1 {One {{message}}}}\r\n` +
            `</div>`,
          'TestComp',
          {
            tokenizeExpansionForms: true,
            escapedString: false,
            i18nNormalizeLineEndingsInICUs: true,
          },
        );

        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'div', 0],
          [html.Text, '\n  ', 1, ['\n  ']],
          [html.Expansion, '\n    messages.length', 'plural', 1],
          [html.ExpansionCase, '=0', 2],
          [html.ExpansionCase, '=1', 2],
          [html.Text, '\n', 1, ['\n']],
        ]);
        const cases = (<any>parsed.rootNodes[0]).children[1].cases;

        expect(humanizeDom(new ParseTreeResult(cases[0].expression, []))).toEqual([
          [html.Text, 'You have \nno\n messages', 0, ['You have \nno\n messages']],
        ]);

        expect(humanizeDom(new ParseTreeResult(cases[1].expression, []))).toEqual([
          [html.Text, 'One {{message}}', 0, ['One '], ['{{', 'message', '}}'], ['']],
        ]);

        expect(parsed.errors).toEqual([]);
      });

      it('should not normalize line-endings in ICU expressions in external templates when `i18nNormalizeLineEndingsInICUs` is not set (escapedString:false)', () => {
        const parsed = parser.parse(
          `<div>\r\n` +
            `  {\r\n` +
            `    messages.length,\r\n` +
            `    plural,\r\n` +
            `    =0 {You have \r\nno\r\n messages}\r\n` +
            `    =1 {One {{message}}}}\r\n` +
            `</div>`,
          'TestComp',
          {tokenizeExpansionForms: true, escapedString: false},
        );

        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'div', 0],
          [html.Text, '\n  ', 1, ['\n  ']],
          [html.Expansion, '\r\n    messages.length', 'plural', 1],
          [html.ExpansionCase, '=0', 2],
          [html.ExpansionCase, '=1', 2],
          [html.Text, '\n', 1, ['\n']],
        ]);
        const cases = (<any>parsed.rootNodes[0]).children[1].cases;

        expect(humanizeDom(new ParseTreeResult(cases[0].expression, []))).toEqual([
          [html.Text, 'You have \nno\n messages', 0, ['You have \nno\n messages']],
        ]);

        expect(humanizeDom(new ParseTreeResult(cases[1].expression, []))).toEqual([
          [html.Text, 'One {{message}}', 0, ['One '], ['{{', 'message', '}}'], ['']],
        ]);

        expect(parsed.errors).toEqual([]);
      });

      it('should parse out expansion forms', () => {
        const parsed = parser.parse(`<div><span>{a, plural, =0 {b}}</span></div>`, 'TestComp', {
          tokenizeExpansionForms: true,
        });

        expect(humanizeDom(parsed)).toEqual([
          [html.Element, 'div', 0],
          [html.Element, 'span', 1],
          [html.Expansion, 'a', 'plural', 2],
          [html.ExpansionCase, '=0', 3],
        ]);
      });

      it('should parse out nested expansion forms', () => {
        const parsed = parser.parse(
          `{messages.length, plural, =0 { {p.gender, select, male {m}} }}`,
          'TestComp',
          {tokenizeExpansionForms: true},
        );
        expect(humanizeDom(parsed)).toEqual([
          [html.Expansion, 'messages.length', 'plural', 0],
          [html.ExpansionCase, '=0', 1],
        ]);

        const firstCase = (<any>parsed.rootNodes[0]).cases[0];

        expect(humanizeDom(new ParseTreeResult(firstCase.expression, []))).toEqual([
          [html.Expansion, 'p.gender', 'select', 0],
          [html.ExpansionCase, 'male', 1],
          [html.Text, ' ', 0, [' ']],
        ]);
      });

      it('should normalize line endings in nested expansion forms for inline templates, when `i18nNormalizeLineEndingsInICUs` is true', () => {
        const parsed = parser.parse(
          `{\r\n` +
            `  messages.length, plural,\r\n` +
            `  =0 { zero \r\n` +
            `       {\r\n` +
            `         p.gender, select,\r\n` +
            `         male {m}\r\n` +
            `       }\r\n` +
            `     }\r\n` +
            `}`,
          'TestComp',
          {
            tokenizeExpansionForms: true,
            escapedString: true,
            i18nNormalizeLineEndingsInICUs: true,
          },
        );
        expect(humanizeDom(parsed)).toEqual([
          [html.Expansion, '\n  messages.length', 'plural', 0],
          [html.ExpansionCase, '=0', 1],
        ]);

        const expansion = parsed.rootNodes[0] as html.Expansion;
        expect(humanizeDom(new ParseTreeResult(expansion.cases[0].expression, []))).toEqual([
          [html.Text, 'zero \n       ', 0, ['zero \n       ']],
          [html.Expansion, '\n         p.gender', 'select', 0],
          [html.ExpansionCase, 'male', 1],
          [html.Text, '\n     ', 0, ['\n     ']],
        ]);

        expect(parsed.errors).toEqual([]);
      });

      it('should not normalize line endings in nested expansion forms for inline templates, when `i18nNormalizeLineEndingsInICUs` is not defined', () => {
        const parsed = parser.parse(
          `{\r\n` +
            `  messages.length, plural,\r\n` +
            `  =0 { zero \r\n` +
            `       {\r\n` +
            `         p.gender, select,\r\n` +
            `         male {m}\r\n` +
            `       }\r\n` +
            `     }\r\n` +
            `}`,
          'TestComp',
          {tokenizeExpansionForms: true, escapedString: true},
        );
        expect(humanizeDom(parsed)).toEqual([
          [html.Expansion, '\r\n  messages.length', 'plural', 0],
          [html.ExpansionCase, '=0', 1],
        ]);

        const expansion = parsed.rootNodes[0] as html.Expansion;
        expect(humanizeDom(new ParseTreeResult(expansion.cases[0].expression, []))).toEqual([
          [html.Text, 'zero \n       ', 0, ['zero \n       ']],
          [html.Expansion, '\r\n         p.gender', 'select', 0],
          [html.ExpansionCase, 'male', 1],
          [html.Text, '\n     ', 0, ['\n     ']],
        ]);

        expect(parsed.errors).toEqual([]);
      });

      it('should not normalize line endings in nested expansion forms for external templates, when `i18nNormalizeLineEndingsInICUs` is not set', () => {
        const parsed = parser.parse(
          `{\r\n` +
            `  messages.length, plural,\r\n` +
            `  =0 { zero \r\n` +
            `       {\r\n` +
            `         p.gender, select,\r\n` +
            `         male {m}\r\n` +
            `       }\r\n` +
            `     }\r\n` +
            `}`,
          'TestComp',
          {tokenizeExpansionForms: true},
        );
        expect(humanizeDom(parsed)).toEqual([
          [html.Expansion, '\r\n  messages.length', 'plural', 0],
          [html.ExpansionCase, '=0', 1],
        ]);

        const expansion = parsed.rootNodes[0] as html.Expansion;
        expect(humanizeDom(new ParseTreeResult(expansion.cases[0].expression, []))).toEqual([
          [html.Text, 'zero \n       ', 0, ['zero \n       ']],
          [html.Expansion, '\r\n         p.gender', 'select', 0],
          [html.ExpansionCase, 'male', 1],
          [html.Text, '\n     ', 0, ['\n     ']],
        ]);

        expect(parsed.errors).toEqual([]);
      });

      it('should error when expansion form is not closed', () => {
        const p = parser.parse(`{messages.length, plural, =0 {one}`, 'TestComp', {
          tokenizeExpansionForms: true,
        });
        expect(humanizeErrors(p.errors)).toEqual([
          [null, "Invalid ICU message. Missing '}'.", '0:34'],
        ]);
      });

      it('should support ICU expressions with cases that contain numbers', () => {
        const p = parser.parse(`{sex, select, male {m} female {f} 0 {other}}`, 'TestComp', {
          tokenizeExpansionForms: true,
        });
        expect(p.errors.length).toEqual(0);
      });

      it(`should support ICU expressions with cases that contain any character except '}'`, () => {
        const p = parser.parse(`{a, select, b {foo} % bar {% bar}}`, 'TestComp', {
          tokenizeExpansionForms: true,
        });
        expect(p.errors.length).toEqual(0);
      });

      it('should error when expansion case is not properly closed', () => {
        const p = parser.parse(`{a, select, b {foo} % { bar {% bar}}`, 'TestComp', {
          tokenizeExpansionForms: true,
        });
        expect(humanizeErrors(p.errors)).toEqual([
          [
            'Unexpected character "EOF" (Do you have an unescaped "{" in your template? Use "{{ \'{\' }}") to escape it.)',
            '0:36',
          ],
          [null, "Invalid ICU message. Missing '}'.", '0:22'],
        ]);
      });

      it('should error when expansion case is not closed', () => {
        const p = parser.parse(`{messages.length, plural, =0 {one`, 'TestComp', {
          tokenizeExpansionForms: true,
        });
        expect(humanizeErrors(p.errors)).toEqual([
          [null, "Invalid ICU message. Missing '}'.", '0:29'],
        ]);
      });

      it('should error when invalid html in the case', () => {
        const p = parser.parse(`{messages.length, plural, =0 {<b/>}`, 'TestComp', {
          tokenizeExpansionForms: true,
        });
        expect(humanizeErrors(p.errors)).toEqual([
          ['b', 'Only void, custom and foreign elements can be self closed "b"', '0:30'],
        ]);
      });
    });

    describe('blocks', () => {
      it('should parse a block', () => {
        expect(humanizeDom(parser.parse('@defer (a b; c d){hello}', 'TestComp'))).toEqual([
          [html.Block, 'defer', 0],
          [html.BlockParameter, 'a b'],
          [html.BlockParameter, 'c d'],
          [html.Text, 'hello', 1, ['hello']],
        ]);
      });

      it('should parse a block with an HTML element', () => {
        expect(humanizeDom(parser.parse('@defer {<my-cmp/>}', 'TestComp'))).toEqual([
          [html.Block, 'defer', 0],
          [html.Element, 'my-cmp', 1, '#selfClosing'],
        ]);
      });

      it('should parse a block containing mixed plain text and HTML', () => {
        expect(
          humanizeDom(
            parser.parse(
              '@switch (expr) {' +
                '@case (1) {hello<my-cmp/>there}' +
                '@case (two) {<p>Two...</p>}' +
                '@case (isThree(3)) {T<strong>htr<i>e</i>e</strong>!}' +
                '}',
              'TestComp',
            ),
          ),
        ).toEqual([
          [html.Block, 'switch', 0],
          [html.BlockParameter, 'expr'],
          [html.Block, 'case', 1],
          [html.BlockParameter, '1'],
          [html.Text, 'hello', 2, ['hello']],
          [html.Element, 'my-cmp', 2, '#selfClosing'],
          [html.Text, 'there', 2, ['there']],
          [html.Block, 'case', 1],
          [html.BlockParameter, 'two'],
          [html.Element, 'p', 2],
          [html.Text, 'Two...', 3, ['Two...']],
          [html.Block, 'case', 1],
          [html.BlockParameter, 'isThree(3)'],
          [html.Text, 'T', 2, ['T']],
          [html.Element, 'strong', 2],
          [html.Text, 'htr', 3, ['htr']],
          [html.Element, 'i', 3],
          [html.Text, 'e', 4, ['e']],
          [html.Text, 'e', 3, ['e']],
          [html.Text, '!', 2, ['!']],
        ]);
      });

      it('should parse nested blocks', () => {
        const markup =
          `<root-sibling-one/>` +
          `@if (root) {` +
          `<outer-child-one/>` +
          `<outer-child-two>` +
          `@if (childParam === 1) {` +
          `@if (innerChild1 === foo) {` +
          `<inner-child-one/>` +
          `@switch (grandChild) {` +
          `@case (innerGrandChild) {` +
          `<inner-grand-child-one/>` +
          `}` +
          `@case (innerGrandChild) {` +
          `<inner-grand-child-two/>` +
          `}` +
          `}` +
          `}` +
          `@if (innerChild) {` +
          `<inner-child-two/>` +
          `}` +
          `}` +
          `</outer-child-two>` +
          `@for (outerChild1; outerChild2) {` +
          `<outer-child-three/>` +
          `}` +
          `} <root-sibling-two/>`;

        expect(humanizeDom(parser.parse(markup, 'TestComp'))).toEqual([
          [html.Element, 'root-sibling-one', 0, '#selfClosing'],
          [html.Block, 'if', 0],
          [html.BlockParameter, 'root'],
          [html.Element, 'outer-child-one', 1, '#selfClosing'],
          [html.Element, 'outer-child-two', 1],
          [html.Block, 'if', 2],
          [html.BlockParameter, 'childParam === 1'],
          [html.Block, 'if', 3],
          [html.BlockParameter, 'innerChild1 === foo'],
          [html.Element, 'inner-child-one', 4, '#selfClosing'],
          [html.Block, 'switch', 4],
          [html.BlockParameter, 'grandChild'],
          [html.Block, 'case', 5],
          [html.BlockParameter, 'innerGrandChild'],
          [html.Element, 'inner-grand-child-one', 6, '#selfClosing'],
          [html.Block, 'case', 5],
          [html.BlockParameter, 'innerGrandChild'],
          [html.Element, 'inner-grand-child-two', 6, '#selfClosing'],
          [html.Block, 'if', 3],
          [html.BlockParameter, 'innerChild'],
          [html.Element, 'inner-child-two', 4, '#selfClosing'],
          [html.Block, 'for', 1],
          [html.BlockParameter, 'outerChild1'],
          [html.BlockParameter, 'outerChild2'],
          [html.Element, 'outer-child-three', 2, '#selfClosing'],
          [html.Text, ' ', 0, [' ']],
          [html.Element, 'root-sibling-two', 0, '#selfClosing'],
        ]);
      });

      it('should infer namespace through block boundary', () => {
        expect(humanizeDom(parser.parse('<svg>@if (cond) {<circle/>}</svg>', 'TestComp'))).toEqual([
          [html.Element, ':svg:svg', 0],
          [html.Block, 'if', 1],
          [html.BlockParameter, 'cond'],
          [html.Element, ':svg:circle', 2, '#selfClosing'],
        ]);
      });

      it('should parse an empty block', () => {
        expect(humanizeDom(parser.parse('@defer{}', 'TestComp'))).toEqual([
          [html.Block, 'defer', 0],
        ]);
      });

      it('should parse a block with void elements', () => {
        expect(humanizeDom(parser.parse('@defer {<br>}', 'TestComp'))).toEqual([
          [html.Block, 'defer', 0],
          [html.Element, 'br', 1],
        ]);
      });

      it('should parse consecutive @case statements', () => {
        expect(
          humanizeDom(
            parser.parse(`@switch (expr) {@case ('foo') @case ('bar') { <input> }}`, `TestComp`),
          ),
        ).toEqual([
          [html.Block, 'switch', 0],
          [html.BlockParameter, 'expr'],
          [html.Block, 'case', 1],
          [html.BlockParameter, `'foo'`],
          [html.Block, 'case', 1],
          [html.BlockParameter, `'bar'`],
          [html.Text, ' ', 2, [' ']],
          [html.Element, 'input', 2],
          [html.Text, ' ', 2, [' ']],
        ]);
      });

      it('should parse empty cases in a switch block', () => {
        expect(
          humanizeDom(
            parser.parse(
              `@switch (expr) {@case ('foo') {} @case ('bar') {bar} @case('baz') { baz }}`,
              `TestComp`,
            ),
          ),
        ).toEqual([
          [html.Block, 'switch', 0],
          [html.BlockParameter, 'expr'],
          [html.Block, 'case', 1],
          [html.BlockParameter, `'foo'`],
          [html.Text, ' ', 1, [' ']],
          [html.Block, 'case', 1],
          [html.BlockParameter, `'bar'`],
          [html.Text, 'bar', 2, ['bar']],
          [html.Text, ' ', 1, [' ']],
          [html.Block, 'case', 1],
          [html.BlockParameter, `'baz'`],
          [html.Text, ' baz ', 2, [' baz ']],
        ]);
      });

      it('should parse exhaustive default checks in a switch block', () => {
        expect(
          humanizeDom(
            parser.parse(`@switch (expr) {@case ('foo') {} @default never;}`, `TestComp`),
          ),
        ).toEqual([
          [html.Block, 'switch', 0],
          [html.BlockParameter, 'expr'],
          [html.Block, 'case', 1],
          [html.BlockParameter, `'foo'`],
          [html.Text, ' ', 1, [' ']],
          [html.Block, 'default never', 1],
        ]);
      });

      it('should close void elements used right before a block', () => {
        expect(humanizeDom(parser.parse('<img>@defer {hello}', 'TestComp'))).toEqual([
          [html.Element, 'img', 0],
          [html.Block, 'defer', 0],
          [html.Text, 'hello', 1, ['hello']],
        ]);
      });

      it('should report an unclosed block', () => {
        const errors = parser.parse('@defer {hello', 'TestComp').errors;
        expect(errors.length).toEqual(1);
        expect(humanizeErrors(errors)).toEqual([['defer', 'Unclosed block "defer"', '0:0']]);
      });

      it('should report an unexpected block close', () => {
        const errors = parser.parse('hello}', 'TestComp').errors;
        expect(errors.length).toEqual(1);
        expect(humanizeErrors(errors)).toEqual([
          [
            null,
            'Unexpected closing block. The block may have been closed earlier. If you meant to write the `}` character, you should use the "&#125;" HTML entity instead.',
            '0:5',
          ],
        ]);
      });

      it('should report unclosed tags inside of a block', () => {
        const errors = parser.parse('@defer {<strong>hello}', 'TestComp').errors;
        expect(errors.length).toEqual(1);
        expect(humanizeErrors(errors)).toEqual([
          [
            null,
            'Unexpected closing block. The block may have been closed earlier. Did you forget to close the <strong> element? If you meant to write the `}` character, you should use the "&#125;" HTML entity instead.',
            '0:21',
          ],
        ]);
      });

      it('should report an unexpected closing tag inside a block', () => {
        const errors = parser.parse('<div>@if (cond) {hello</div>}', 'TestComp').errors;
        expect(errors.length).toEqual(2);
        expect(humanizeErrors(errors)).toEqual([
          [
            'div',
            'Unexpected closing tag "div". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags',
            '0:22',
          ],
          [
            null,
            'Unexpected closing block. The block may have been closed earlier. If you meant to write the `}` character, you should use the "&#125;" HTML entity instead.',
            '0:28',
          ],
        ]);
      });

      it('should report a final @case without a body', () => {
        const errors = parser.parse('@switch (expr) {@case (1)}', 'TestComp').errors;
        expect(errors.length).toEqual(1);
        expect(humanizeErrors(errors)).toEqual([
          [
            'case',
            'Incomplete block "case". If you meant to write the @ character, you should use the "&#64;" HTML entity instead.',
            '0:16',
          ],
        ]);
      });

      it('should store the source locations of blocks', () => {
        const markup =
          '@switch (expr) {' +
          '@case (1) {<div>hello</div>world}' +
          '@case (two) {Two}' +
          '@case (isThree(3)) {Placeholde<strong>r</strong>}' +
          '}';

        expect(humanizeDomSourceSpans(parser.parse(markup, 'TestComp'))).toEqual([
          [
            html.Block,
            'switch',
            0,
            '@switch (expr) {@case (1) {<div>hello</div>world}@case (two) {Two}@case (isThree(3)) {Placeholde<strong>r</strong>}}',
            '@switch (expr) {',
            '}',
          ],
          [html.BlockParameter, 'expr', 'expr'],
          [html.Block, 'case', 1, '@case (1) {<div>hello</div>world}', '@case (1) {', '}'],
          [html.BlockParameter, '1', '1'],
          [html.Element, 'div', 2, '<div>hello</div>', '<div>', '</div>'],
          [html.Text, 'hello', 3, ['hello'], 'hello'],
          [html.Text, 'world', 2, ['world'], 'world'],
          [html.Block, 'case', 1, '@case (two) {Two}', '@case (two) {', '}'],
          [html.BlockParameter, 'two', 'two'],
          [html.Text, 'Two', 2, ['Two'], 'Two'],
          [
            html.Block,
            'case',
            1,
            '@case (isThree(3)) {Placeholde<strong>r</strong>}',
            '@case (isThree(3)) {',
            '}',
          ],
          [html.BlockParameter, 'isThree(3)', 'isThree(3)'],
          [html.Text, 'Placeholde', 2, ['Placeholde'], 'Placeholde'],
          [html.Element, 'strong', 2, '<strong>r</strong>', '<strong>', '</strong>'],
          [html.Text, 'r', 3, ['r'], 'r'],
        ]);
      });

      it('should parse an incomplete block with no parameters', () => {
        const result = parser.parse('This is the @if() block', 'TestComp');

        expect(humanizeNodes(result.rootNodes, true)).toEqual([
          [html.Text, 'This is the ', 0, ['This is the '], 'This is the '],
          [html.Block, 'if', 0, '@if() ', '@if() ', null],
          [html.Text, 'block', 0, ['block'], 'block'],
        ]);

        expect(humanizeErrors(result.errors)).toEqual([
          [
            'if',
            'Incomplete block "if". If you meant to write the @ character, you should use the "&#64;" HTML entity instead.',
            '0:12',
          ],
        ]);
      });

      it('should parse an incomplete block with no body', () => {
        const result = parser.parse(
          'This is the @if({alias: "foo"}) block with params',
          'TestComp',
        );

        expect(humanizeNodes(result.rootNodes, true)).toEqual([
          [html.Text, 'This is the ', 0, ['This is the '], 'This is the '],
          [html.Block, 'if', 0, '@if({alias: "foo"}) ', '@if({alias: "foo"}) ', null],
          [html.BlockParameter, '{alias: "foo"}', '{alias: "foo"}'],
          [html.Text, 'block with params', 0, ['block with params'], 'block with params'],
        ]);

        expect(humanizeErrors(result.errors)).toEqual([
          [
            'if',
            'Incomplete block "if". If you meant to write the @ character, you should use the "&#64;" HTML entity instead.',
            '0:12',
          ],
        ]);
      });
    });

    describe('let declaration', () => {
      it('should parse a let declaration', () => {
        expect(humanizeDom(parser.parse('@let foo = 123;', 'TestCmp'))).toEqual([
          [html.LetDeclaration, 'foo', '123'],
        ]);
      });

      it('should parse a let declaration that is nested in a parent', () => {
        expect(
          humanizeDom(parser.parse('@defer {@if (true) {@let foo = 123;}}', 'TestCmp')),
        ).toEqual([
          [html.Block, 'defer', 0],
          [html.Block, 'if', 1],
          [html.BlockParameter, 'true'],
          [html.LetDeclaration, 'foo', '123'],
        ]);
      });

      it('should store the source location of a @let declaration', () => {
        expect(humanizeDomSourceSpans(parser.parse('@let foo = 123 + 456;', 'TestCmp'))).toEqual([
          [html.LetDeclaration, 'foo', '123 + 456', '@let foo = 123 + 456;', 'foo', '123 + 456'],
        ]);
      });

      it('should report an error for an incomplete let declaration', () => {
        expect(humanizeErrors(parser.parse('@let foo =', 'TestCmp').errors)).toEqual([
          [
            'foo',
            'Incomplete @let declaration "foo". @let declarations must be written as `@let <name> = <value>;`',
            '0:0',
          ],
        ]);
      });

      it('should store the locations of an incomplete let declaration', () => {
        const parseResult = parser.parse('@let foo =', 'TestCmp');

        // It's expected that errors will be reported for the incomplete declaration,
        // but we still want to check the spans since they're important even for broken templates.
        parseResult.errors = [];

        expect(humanizeDomSourceSpans(parseResult)).toEqual([
          [html.LetDeclaration, 'foo', '', '@let foo =', 'foo =', ''],
        ]);
      });
    });

    describe('directive nodes', () => {
      const options: TokenizeOptions = {
        selectorlessEnabled: true,
      };

      it('should parse a directive with no attributes', () => {
        const parsed = humanizeDom(parser.parse('<div @Dir></div>', '', options));

        expect(parsed).toEqual([
          [html.Element, 'div', 0],
          [html.Directive, 'Dir'],
        ]);
      });

      it('should parse a directive with attributes', () => {
        const parsed = humanizeDom(
          parser.parse('<div @Dir(a="1" [b]="two" (c)="c()")></div>', '', options),
        );

        expect(parsed).toEqual([
          [html.Element, 'div', 0],
          [html.Directive, 'Dir'],
          [html.Attribute, 'a', '1', ['1']],
          [html.Attribute, '[b]', 'two', ['two']],
          [html.Attribute, '(c)', 'c()', ['c()']],
        ]);
      });

      it('should parse directives on a component node', () => {
        const parsed = humanizeDom(
          parser.parse('<MyComp @Dir @OtherDir(a="1" [b]="two" (c)="c()")></MyComp>', '', options),
        );

        expect(parsed).toEqual([
          [html.Component, 'MyComp', null, 'MyComp', 0],
          [html.Directive, 'Dir'],
          [html.Directive, 'OtherDir'],
          [html.Attribute, 'a', '1', ['1']],
          [html.Attribute, '[b]', 'two', ['two']],
          [html.Attribute, '(c)', 'c()', ['c()']],
        ]);
      });

      it('should report a missing directive closing paren', () => {
        expect(
          humanizeErrors(parser.parse('<div @Dir(a="1" (b)="2"></div>', '', options).errors),
        ).toEqual([[null, 'Unterminated directive definition', '0:5']]);
        expect(
          humanizeErrors(parser.parse('<MyComp @Dir(a="1" (b)="2"/>', '', options).errors),
        ).toEqual([[null, 'Unterminated directive definition', '0:8']]);
      });

      it('should parse a directive mixed with other attributes', () => {
        const parsed = humanizeDom(
          parser.parse(
            '<div before="foo" @Dir middle @OtherDir([a]="a" (b)="b()") after="123"></div>',
            '',
            options,
          ),
        );

        expect(parsed).toEqual([
          [html.Element, 'div', 0],
          [html.Attribute, 'before', 'foo', ['foo']],
          [html.Attribute, 'middle', ''],
          [html.Attribute, 'after', '123', ['123']],
          [html.Directive, 'Dir'],
          [html.Directive, 'OtherDir'],
          [html.Attribute, '[a]', 'a', ['a']],
          [html.Attribute, '(b)', 'b()', ['b()']],
        ]);
      });

      it('should store the source locations of directives', () => {
        const markup = '<div @Dir @OtherDir(a="1" [b]="two" (c)="c()")></div>';

        expect(humanizeDomSourceSpans(parser.parse(markup, '', options))).toEqual([
          [
            html.Element,
            'div',
            0,
            '<div @Dir @OtherDir(a="1" [b]="two" (c)="c()")></div>',
            '<div @Dir @OtherDir(a="1" [b]="two" (c)="c()")>',
            '</div>',
          ],
          [html.Directive, 'Dir', '@Dir', '@Dir', null],
          [html.Directive, 'OtherDir', '@OtherDir(a="1" [b]="two" (c)="c()")', '@OtherDir(', ')'],
          [html.Attribute, 'a', '1', ['1'], 'a="1"'],
          [html.Attribute, '[b]', 'two', ['two'], '[b]="two"'],
          [html.Attribute, '(c)', 'c()', ['c()'], '(c)="c()"'],
        ]);
      });
    });

    describe('component nodes', () => {
      const options: TokenizeOptions = {
        selectorlessEnabled: true,
      };

      it('should parse a simple component node', () => {
        const parsed = humanizeDom(parser.parse('<MyComp>Hello</MyComp>', '', options));

        expect(parsed).toEqual([
          [html.Component, 'MyComp', null, 'MyComp', 0],
          [html.Text, 'Hello', 1, ['Hello']],
        ]);
      });

      it('should parse a self-closing component node', () => {
        const parsed = humanizeDom(parser.parse('<MyComp/>Hello', '', options));

        expect(parsed).toEqual([
          [html.Component, 'MyComp', null, 'MyComp', 0, '#selfClosing'],
          [html.Text, 'Hello', 0, ['Hello']],
        ]);
      });

      it('should parse a component node with a tag name', () => {
        const parsed = humanizeDom(
          parser.parse('<MyComp:button>Hello</MyComp:button>', '', options),
        );

        expect(parsed).toEqual([
          [html.Component, 'MyComp', 'button', 'MyComp:button', 0],
          [html.Text, 'Hello', 1, ['Hello']],
        ]);
      });

      it('should parse a component node with a tag name and namespace', () => {
        const parsed = humanizeDom(
          parser.parse('<MyComp:svg:title>Hello</MyComp:svg:title>', '', options),
        );

        expect(parsed).toEqual([
          [html.Component, 'MyComp', ':svg:title', 'MyComp:svg:title', 0],
          [html.Text, 'Hello', 1, ['Hello']],
        ]);
      });

      it('should parse a component node with an inferred namespace and no tag name', () => {
        const parsed = humanizeDom(parser.parse('<svg><MyComp>Hello</MyComp></svg>', '', options));

        expect(parsed).toEqual([
          [html.Element, ':svg:svg', 0],
          [html.Component, 'MyComp', ':svg:ng-component', 'MyComp:svg:ng-component', 1],
          [html.Text, 'Hello', 2, ['Hello']],
        ]);
      });

      it('should parse a component node with an inferred namespace and a tag name', () => {
        const parsed = humanizeDom(
          parser.parse('<svg><MyComp:button>Hello</MyComp:button></svg>', '', options),
        );

        expect(parsed).toEqual([
          [html.Element, ':svg:svg', 0],
          [html.Component, 'MyComp', ':svg:button', 'MyComp:svg:button', 1],
          [html.Text, 'Hello', 2, ['Hello']],
        ]);
      });

      it('should parse a component node with an inferred namespace plus an explicit namespace and tag name', () => {
        const parsed = humanizeDom(
          parser.parse('<math><MyComp:svg:title>Hello</MyComp:svg:title></math>', '', options),
        );

        expect(parsed).toEqual([
          [html.Element, ':math:math', 0],
          [html.Component, 'MyComp', ':svg:title', 'MyComp:svg:title', 1],
          [html.Text, 'Hello', 2, ['Hello']],
        ]);
      });

      it('should distinguish components with tag names from ones without', () => {
        const parsed = humanizeDom(
          parser.parse('<MyComp:button><MyComp>Hello</MyComp></MyComp:button>', '', options),
        );

        expect(parsed).toEqual([
          [html.Component, 'MyComp', 'button', 'MyComp:button', 0],
          [html.Component, 'MyComp', null, 'MyComp', 1],
          [html.Text, 'Hello', 2, ['Hello']],
        ]);
      });

      it('should implicitly close a component', () => {
        const parsed = humanizeDom(parser.parse('<MyComp>Hello', '', options));

        expect(parsed).toEqual([
          [html.Component, 'MyComp', null, 'MyComp', 0],
          [html.Text, 'Hello', 1, ['Hello']],
        ]);
      });

      it('should parse a component tag nested within other markup', () => {
        const parsed = humanizeDom(
          parser.parse(
            '@if (expr) {<div>Hello: <MyComp><span><OtherComp/></span></MyComp></div>}',
            '',
            options,
          ),
        );

        expect(parsed).toEqual([
          [html.Block, 'if', 0],
          [html.BlockParameter, 'expr'],
          [html.Element, 'div', 1],
          [html.Text, 'Hello: ', 2, ['Hello: ']],
          [html.Component, 'MyComp', null, 'MyComp', 2],
          [html.Element, 'span', 3],
          [html.Component, 'OtherComp', null, 'OtherComp', 4, '#selfClosing'],
        ]);
      });

      it('should report closing tag whose tag name does not match the opening tag', () => {
        expect(
          humanizeErrors(parser.parse('<MyComp:button>Hello</MyComp>', '', options).errors),
        ).toEqual([
          ['MyComp', 'Unexpected closing tag "MyComp", did you mean "MyComp:button"?', '0:20'],
        ]);
        expect(
          humanizeErrors(parser.parse('<MyComp>Hello</MyComp:button>', '', options).errors),
        ).toEqual([
          [
            'MyComp:button',
            'Unexpected closing tag "MyComp:button", did you mean "MyComp"?',
            '0:13',
          ],
        ]);
      });

      it('should parse a component node with attributes and directives', () => {
        const parsed = humanizeDom(
          parser.parse(
            '<MyComp before="foo" @Dir middle @OtherDir([a]="a" (b)="b()") after="123">Hello</MyComp>',
            '',
            options,
          ),
        );

        expect(parsed).toEqual([
          [html.Component, 'MyComp', null, 'MyComp', 0],
          [html.Attribute, 'before', 'foo', ['foo']],
          [html.Attribute, 'middle', ''],
          [html.Attribute, 'after', '123', ['123']],
          [html.Directive, 'Dir'],
          [html.Directive, 'OtherDir'],
          [html.Attribute, '[a]', 'a', ['a']],
          [html.Attribute, '(b)', 'b()', ['b()']],
          [html.Text, 'Hello', 1, ['Hello']],
        ]);
      });

      it('should store the source locations of a component with attributes and content', () => {
        const markup = '<MyComp one="1" two [three]="3">Hello</MyComp>';

        expect(humanizeDomSourceSpans(parser.parse(markup, '', options))).toEqual([
          [
            html.Component,
            'MyComp',
            null,
            'MyComp',
            0,
            '<MyComp one="1" two [three]="3">Hello</MyComp>',
            '<MyComp one="1" two [three]="3">',
            '</MyComp>',
          ],
          [html.Attribute, 'one', '1', ['1'], 'one="1"'],
          [html.Attribute, 'two', '', 'two'],
          [html.Attribute, '[three]', '3', ['3'], '[three]="3"'],
          [html.Text, 'Hello', 1, ['Hello'], 'Hello'],
        ]);
      });

      it('should store the source locations of self-closing components', () => {
        const markup = '<MyComp one="1" two [three]="3"/>Hello<MyOtherComp/><MyThirdComp:button/>';

        expect(humanizeDomSourceSpans(parser.parse(markup, '', options))).toEqual([
          [
            html.Component,
            'MyComp',
            null,
            'MyComp',
            0,
            '<MyComp one="1" two [three]="3"/>',
            '#selfClosing',
            '<MyComp one="1" two [three]="3"/>',
            '<MyComp one="1" two [three]="3"/>',
          ],
          [html.Attribute, 'one', '1', ['1'], 'one="1"'],
          [html.Attribute, 'two', '', 'two'],
          [html.Attribute, '[three]', '3', ['3'], '[three]="3"'],
          [html.Text, 'Hello', 0, ['Hello'], 'Hello'],
          [
            html.Component,
            'MyOtherComp',
            null,
            'MyOtherComp',
            0,
            '<MyOtherComp/>',
            '#selfClosing',
            '<MyOtherComp/>',
            '<MyOtherComp/>',
          ],
          [
            html.Component,
            'MyThirdComp',
            'button',
            'MyThirdComp:button',
            0,
            '<MyThirdComp:button/>',
            '#selfClosing',
            '<MyThirdComp:button/>',
            '<MyThirdComp:button/>',
          ],
        ]);
      });
    });

    describe('ignored syntax', () => {
      it('should ignore doctype declaration', () => {
        expect(humanizeDom(parser.parse(`<!DOCTYPE html>hello`, 'TestComp'))).toEqual([
          [html.Text, 'hello', 0, ['hello']],
        ]);
      });

      it('should ignore processing instruction', () => {
        expect(
          humanizeDom(parser.parse(`<?xml version="1.0" encoding="UTF-8"?>hello`, 'TestComp')),
        ).toEqual([[html.Text, 'hello', 0, ['hello']]]);
      });
    });

    describe('source spans', () => {
      it('should store the location', () => {
        expect(
          humanizeDomSourceSpans(
            parser.parse('<div [prop]="v1" (e)="do()" attr="v2" noValue>\na\n</div>', ' TestComp'),
          ),
        ).toEqual([
          [
            html.Element,
            'div',
            0,
            '<div [prop]="v1" (e)="do()" attr="v2" noValue>\na\n</div>',
            '<div [prop]="v1" (e)="do()" attr="v2" noValue>',
            '</div>',
          ],
          [html.Attribute, '[prop]', 'v1', ['v1'], '[prop]="v1"'],
          [html.Attribute, '(e)', 'do()', ['do()'], '(e)="do()"'],
          [html.Attribute, 'attr', 'v2', ['v2'], 'attr="v2"'],
          [html.Attribute, 'noValue', '', 'noValue'],
          [html.Text, '\na\n', 1, ['\na\n'], '\na\n'],
        ]);
      });

      it('should set the start and end source spans', () => {
        const node = <html.Element>parser.parse('<div>a</div>', 'TestComp').rootNodes[0];

        expect(node.startSourceSpan.start.offset).toEqual(0);
        expect(node.startSourceSpan.end.offset).toEqual(5);

        expect(node.endSourceSpan!.start.offset).toEqual(6);
        expect(node.endSourceSpan!.end.offset).toEqual(12);
      });

      // This checks backward compatibility with a previous version of the lexer, which would
      // treat interpolation expressions as regular HTML escapable text.
      it('should decode HTML entities in interpolations', () => {
        expect(
          humanizeDomSourceSpans(
            parser.parse(
              '{{&amp;}}' +
                '{{&#x25BE;}}' +
                '{{&#9662;}}' +
                '{{&unknown;}}' +
                '{{&amp (no semi-colon)}}' +
                '{{&#xyz; (invalid hex)}}' +
                '{{&#25BE; (invalid decimal)}}',
              'TestComp',
            ),
          ),
        ).toEqual([
          [
            html.Text,
            '{{&}}' +
              '{{\u25BE}}' +
              '{{\u25BE}}' +
              '{{&unknown;}}' +
              '{{&amp (no semi-colon)}}' +
              '{{&#xyz; (invalid hex)}}' +
              '{{&#25BE; (invalid decimal)}}',
            0,
            [''],
            ['{{', '&amp;', '}}'],
            [''],
            ['{{', '&#x25BE;', '}}'],
            [''],
            ['{{', '&#9662;', '}}'],
            [''],
            ['{{', '&unknown;', '}}'],
            [''],
            ['{{', '&amp (no semi-colon)', '}}'],
            [''],
            ['{{', '&#xyz; (invalid hex)', '}}'],
            [''],
            ['{{', '&#25BE; (invalid decimal)', '}}'],
            [''],
            '{{&amp;}}' +
              '{{&#x25BE;}}' +
              '{{&#9662;}}' +
              '{{&unknown;}}' +
              '{{&amp (no semi-colon)}}' +
              '{{&#xyz; (invalid hex)}}' +
              '{{&#25BE; (invalid decimal)}}',
          ],
        ]);
      });

      it('should decode HTML entities with 5+ hex digits in interpolations', () => {
        // Test with 🛈 (U+1F6C8 - Circled Information Source)
        expect(
          humanizeDomSourceSpans(parser.parse('{{&#x1F6C8;}}' + '{{&#128712;}}', 'TestComp')),
        ).toEqual([
          [
            html.Text,
            '{{\u{1F6C8}}}' + '{{\u{1F6C8}}}',
            0,
            [''],
            ['{{', '&#x1F6C8;', '}}'],
            [''],
            ['{{', '&#128712;', '}}'],
            [''],
            '{{&#x1F6C8;}}' + '{{&#128712;}}',
          ],
        ]);
      });

      it('should support interpolations in text', () => {
        expect(
          humanizeDomSourceSpans(parser.parse('<div> pre {{ value }} post </div>', 'TestComp')),
        ).toEqual([
          [html.Element, 'div', 0, '<div> pre {{ value }} post </div>', '<div>', '</div>'],
          [
            html.Text,
            ' pre {{ value }} post ',
            1,
            [' pre '],
            ['{{', ' value ', '}}'],
            [' post '],
            ' pre {{ value }} post ',
          ],
        ]);
      });

      it('should not set the end source span for void elements', () => {
        expect(humanizeDomSourceSpans(parser.parse('<div><br></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0, '<div><br></div>', '<div>', '</div>'],
          [html.Element, 'br', 1, '<br>', '<br>', null],
        ]);
      });

      it('should not set the end source span for multiple void elements', () => {
        expect(humanizeDomSourceSpans(parser.parse('<div><br><hr></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0, '<div><br><hr></div>', '<div>', '</div>'],
          [html.Element, 'br', 1, '<br>', '<br>', null],
          [html.Element, 'hr', 1, '<hr>', '<hr>', null],
        ]);
      });

      it('should not set the end source span for standalone void elements', () => {
        expect(humanizeDomSourceSpans(parser.parse('<br>', 'TestComp'))).toEqual([
          [html.Element, 'br', 0, '<br>', '<br>', null],
        ]);
      });

      it('should set the end source span for standalone self-closing elements', () => {
        expect(humanizeDomSourceSpans(parser.parse('<br/>', 'TestComp'))).toEqual([
          [html.Element, 'br', 0, '<br/>', '#selfClosing', '<br/>', '<br/>'],
        ]);
      });

      it('should set the end source span for self-closing elements', () => {
        expect(humanizeDomSourceSpans(parser.parse('<div><br/></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0, '<div><br/></div>', '<div>', '</div>'],
          [html.Element, 'br', 1, '<br/>', '#selfClosing', '<br/>', '<br/>'],
        ]);
      });

      it('should not include leading trivia from the following node of an element in the end source', () => {
        expect(
          humanizeDomSourceSpans(
            parser.parse('<input type="text" />\n\n\n  <span>\n</span>', 'TestComp', {
              leadingTriviaChars: [' ', '\n', '\r', '\t'],
            }),
          ),
        ).toEqual([
          [
            html.Element,
            'input',
            0,
            '<input type="text" />',
            '#selfClosing',
            '<input type="text" />',
            '<input type="text" />',
          ],
          [html.Attribute, 'type', 'text', ['text'], 'type="text"'],
          [html.Text, '\n\n\n  ', 0, ['\n\n\n  '], '', '\n\n\n  '],
          [html.Element, 'span', 0, '<span>\n</span>', '<span>', '</span>'],
          [html.Text, '\n', 1, ['\n'], '', '\n'],
        ]);
      });

      it('should not set the end source span for elements that are implicitly closed', () => {
        expect(humanizeDomSourceSpans(parser.parse('<div><p></div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0, '<div><p></div>', '<div>', '</div>'],
          [html.Element, 'p', 1, '<p>', '<p>', null],
        ]);
        expect(humanizeDomSourceSpans(parser.parse('<div><li>A<li>B</div>', 'TestComp'))).toEqual([
          [html.Element, 'div', 0, '<div><li>A<li>B</div>', '<div>', '</div>'],
          [html.Element, 'li', 1, '<li>', '<li>', null],
          [html.Text, 'A', 2, ['A'], 'A'],
          [html.Element, 'li', 1, '<li>', '<li>', null],
          [html.Text, 'B', 2, ['B'], 'B'],
        ]);
      });

      it('should support expansion form', () => {
        expect(
          humanizeDomSourceSpans(
            parser.parse('<div>{count, plural, =0 {msg}}</div>', 'TestComp', {
              tokenizeExpansionForms: true,
            }),
          ),
        ).toEqual([
          [html.Element, 'div', 0, '<div>{count, plural, =0 {msg}}</div>', '<div>', '</div>'],
          [html.Expansion, 'count', 'plural', 1, '{count, plural, =0 {msg}}'],
          [html.ExpansionCase, '=0', 2, '=0 {msg}'],
        ]);
      });

      it('should not report a value span for an attribute without a value', () => {
        const ast = parser.parse('<div bar></div>', 'TestComp');
        expect((ast.rootNodes[0] as html.Element).attrs[0].valueSpan).toBeUndefined();
      });

      it('should report a value span for an attribute with a value', () => {
        const ast = parser.parse('<div bar="12"></div>', 'TestComp');
        const attr = (ast.rootNodes[0] as html.Element).attrs[0];
        expect(attr.valueSpan!.start.offset).toEqual(10);
        expect(attr.valueSpan!.end.offset).toEqual(12);
      });

      it('should report a value span for an unquoted attribute value', () => {
        const ast = parser.parse('<div bar=12></div>', 'TestComp');
        const attr = (ast.rootNodes[0] as html.Element).attrs[0];
        expect(attr.valueSpan!.start.offset).toEqual(9);
        expect(attr.valueSpan!.end.offset).toEqual(11);
      });
    });

    describe('visitor', () => {
      it('should visit text nodes', () => {
        const result = humanizeDom(parser.parse('text', 'TestComp'));
        expect(result).toEqual([[html.Text, 'text', 0, ['text']]]);
      });

      it('should visit element nodes', () => {
        const result = humanizeDom(parser.parse('<div></div>', 'TestComp'));
        expect(result).toEqual([[html.Element, 'div', 0]]);
      });

      it('should visit attribute nodes', () => {
        const result = humanizeDom(parser.parse('<div id="foo"></div>', 'TestComp'));
        expect(result).toContain([html.Attribute, 'id', 'foo', ['foo']]);
      });

      it('should visit all nodes', () => {
        const result = parser.parse(
          '<div id="foo"><span id="bar">a</span><span>b</span></div>',
          'TestComp',
        );
        const accumulator: html.Node[] = [];
        const visitor = new (class implements html.Visitor {
          visit(node: html.Node, context: any) {
            accumulator.push(node);
          }
          visitElement(element: html.Element, context: any): any {
            html.visitAll(this, element.attrs);
            html.visitAll(this, element.directives);
            html.visitAll(this, element.children);
          }
          visitAttribute(attribute: html.Attribute, context: any): any {}
          visitText(text: html.Text, context: any): any {}
          visitComment(comment: html.Comment, context: any): any {}
          visitExpansion(expansion: html.Expansion, context: any): any {
            html.visitAll(this, expansion.cases);
          }
          visitExpansionCase(expansionCase: html.ExpansionCase, context: any): any {}
          visitBlock(block: html.Block, context: any) {
            html.visitAll(this, block.parameters);
            html.visitAll(this, block.children);
          }
          visitBlockParameter(parameter: html.BlockParameter, context: any) {}
          visitLetDeclaration(decl: html.LetDeclaration, context: any) {}
          visitComponent(component: html.Component, context: any) {
            html.visitAll(this, component.attrs);
            html.visitAll(this, component.directives);
            html.visitAll(this, component.children);
          }
          visitDirective(directive: html.Directive, context: any) {
            html.visitAll(this, directive.attrs);
          }
        })();

        html.visitAll(visitor, result.rootNodes);
        expect(accumulator.map((n) => n.constructor)).toEqual([
          html.Element,
          html.Attribute,
          html.Element,
          html.Attribute,
          html.Text,
          html.Element,
          html.Text,
        ]);
      });

      it('should skip typed visit if visit() returns a truthy value', () => {
        const visitor = new (class implements html.Visitor {
          visit(node: html.Node, context: any) {
            return true;
          }
          visitElement(element: html.Element, context: any): any {
            throw Error('Unexpected');
          }
          visitAttribute(attribute: html.Attribute, context: any): any {
            throw Error('Unexpected');
          }
          visitText(text: html.Text, context: any): any {
            throw Error('Unexpected');
          }
          visitComment(comment: html.Comment, context: any): any {
            throw Error('Unexpected');
          }
          visitExpansion(expansion: html.Expansion, context: any): any {
            throw Error('Unexpected');
          }
          visitExpansionCase(expansionCase: html.ExpansionCase, context: any): any {
            throw Error('Unexpected');
          }
          visitBlock(block: html.Block, context: any) {
            throw Error('Unexpected');
          }
          visitBlockParameter(parameter: html.BlockParameter, context: any) {
            throw Error('Unexpected');
          }
          visitLetDeclaration(decl: html.LetDeclaration, context: any) {
            throw Error('Unexpected');
          }
          visitComponent(component: html.Component, context: any) {
            throw Error('Unexpected');
          }
          visitDirective(directive: html.Directive, context: any) {
            throw Error('Unexpected');
          }
        })();
        const result = parser.parse('<div id="foo"></div><div id="bar"></div>', 'TestComp');
        const traversal = html.visitAll(visitor, result.rootNodes);
        expect(traversal).toEqual([true, true]);
      });
    });

    describe('errors', () => {
      it('should report unexpected closing tags', () => {
        const errors = parser.parse('<div></p></div>', 'TestComp').errors;
        expect(errors.length).toEqual(1);
        expect(humanizeErrors(errors)).toEqual([
          [
            'p',
            'Unexpected closing tag "p". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags',
            '0:5',
          ],
        ]);
      });

      it('gets correct close tag for parent when a child is not closed', () => {
        const {errors, rootNodes} = parser.parse('<div><span></div>', 'TestComp');
        expect(errors.length).toEqual(1);
        expect(humanizeErrors(errors)).toEqual([
          [
            'div',
            'Unexpected closing tag "div". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags',
            '0:11',
          ],
        ]);
        expect(humanizeNodes(rootNodes, true)).toEqual([
          [html.Element, 'div', 0, '<div><span></div>', '<div>', '</div>'],
          [html.Element, 'span', 1, '<span>', '<span>', null],
        ]);
      });

      describe('incomplete element tag', () => {
        it('should parse and report incomplete tags after the tag name', () => {
          const {errors, rootNodes} = parser.parse('<div<span><div  </span>', 'TestComp');

          expect(humanizeNodes(rootNodes, true)).toEqual([
            [html.Element, 'div', 0, '<div', '<div', null],
            [html.Element, 'span', 0, '<span><div  </span>', '<span>', '</span>'],
            [html.Element, 'div', 1, '<div  ', '<div  ', null],
          ]);

          expect(humanizeErrors(errors)).toEqual([
            ['div', 'Opening tag "div" not terminated.', '0:0'],
            ['div', 'Opening tag "div" not terminated.', '0:10'],
          ]);
        });

        it('should parse and report incomplete tags after attribute', () => {
          const {errors, rootNodes} = parser.parse('<div class="hi" sty<span></span>', 'TestComp');

          expect(humanizeNodes(rootNodes, true)).toEqual([
            [html.Element, 'div', 0, '<div class="hi" sty', '<div class="hi" sty', null],
            [html.Attribute, 'class', 'hi', ['hi'], 'class="hi"'],
            [html.Attribute, 'sty', '', 'sty'],
            [html.Element, 'span', 0, '<span></span>', '<span>', '</span>'],
          ]);

          expect(humanizeErrors(errors)).toEqual([
            ['div', 'Opening tag "div" not terminated.', '0:0'],
          ]);
        });

        it('should parse and report incomplete tags after quote', () => {
          const {errors, rootNodes} = parser.parse('<div "<span></span>', 'TestComp');

          expect(humanizeNodes(rootNodes, true)).toEqual([
            [html.Element, 'div', 0, '<div ', '<div ', null],
            [html.Text, '"', 0, ['"'], '"'],
            [html.Element, 'span', 0, '<span></span>', '<span>', '</span>'],
          ]);

          expect(humanizeErrors(errors)).toEqual([
            ['div', 'Opening tag "div" not terminated.', '0:0'],
          ]);
        });

        it('should report subsequent open tags without proper close tag', () => {
          const errors = parser.parse('<div</div>', 'TestComp').errors;
          expect(errors.length).toEqual(2);
          expect(humanizeErrors(errors)).toEqual([
            ['div', 'Opening tag "div" not terminated.', '0:0'],
            // TODO(ayazhafiz): the following error is unnecessary and can be pruned if we keep
            // track of the incomplete tag names.
            [
              'div',
              'Unexpected closing tag "div". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags',
              '0:4',
            ],
          ]);
        });
      });

      it('should report closing tag for void elements', () => {
        const errors = parser.parse('<input></input>', 'TestComp').errors;
        expect(errors.length).toEqual(1);
        expect(humanizeErrors(errors)).toEqual([
          ['input', 'Void elements do not have end tags "input"', '0:7'],
        ]);
      });

      it('should report self closing html element', () => {
        const errors = parser.parse('<p />', 'TestComp').errors;
        expect(errors.length).toEqual(1);
        expect(humanizeErrors(errors)).toEqual([
          ['p', 'Only void, custom and foreign elements can be self closed "p"', '0:0'],
        ]);
      });

      it('should not report self closing custom element', () => {
        expect(parser.parse('<my-cmp />', 'TestComp').errors).toEqual([]);
      });

      it('should also report lexer errors', () => {
        const errors = parser.parse('<!-err--><div></p></div>', 'TestComp').errors;
        expect(errors.length).toEqual(2);
        expect(humanizeErrors(errors)).toEqual([
          ['Unexpected character "e"', '0:3'],
          [
            'p',
            'Unexpected closing tag "p". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags',
            '0:14',
          ],
        ]);
      });
    });
  });
});

export function humanizeErrors(errors: ParseError[]): any[] {
  return errors.map((e) => {
    if (e instanceof TreeError) {
      // Parser errors
      return [<any>e.elementName, e.msg, humanizeLineColumn(e.span.start)];
    }
    // Tokenizer errors
    return [e.msg, humanizeLineColumn(e.span.start)];
  });
}