;" syntax', '0:0'
        ]]);
        expect(tokenizeAndHumanizeErrors('sdf;')).toEqual([
          [lex.TokenType.TEXT, 'Unexpected character "s"', '0:3']
        ]);
        expect(tokenizeAndHumanizeErrors('
sdf;')).toEqual([
          [lex.TokenType.TEXT, 'Unexpected character "s"', '0:4']
        ]);
        expect(tokenizeAndHumanizeErrors('઼')).toEqual([
          [lex.TokenType.TEXT, 'Unexpected character "EOF"', '0:6']
        ]);
      });
    });
    describe('regular text', () => {
      it('should parse text', () => {
        expect(tokenizeAndHumanizeParts('a')).toEqual([
          [lex.TokenType.TEXT, 'a'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should parse interpolation', () => {
        expect(tokenizeAndHumanizeParts('{{ a }}b{{ c // comment }}')).toEqual([
          [lex.TokenType.TEXT, '{{ a }}b{{ c // comment }}'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should parse interpolation with custom markers', () => {
        expect(tokenizeAndHumanizeParts('{% a %}', {interpolationConfig: {start: '{%', end: '%}'}}))
            .toEqual([
              [lex.TokenType.TEXT, '{% a %}'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should handle CR & LF', () => {
        expect(tokenizeAndHumanizeParts('t\ne\rs\r\nt')).toEqual([
          [lex.TokenType.TEXT, 't\ne\ns\nt'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should parse entities', () => {
        expect(tokenizeAndHumanizeParts('a&b')).toEqual([
          [lex.TokenType.TEXT, 'a&b'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should parse text starting with "&"', () => {
        expect(tokenizeAndHumanizeParts('a && b &')).toEqual([
          [lex.TokenType.TEXT, 'a && b &'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should store the locations', () => {
        expect(tokenizeAndHumanizeSourceSpans('a')).toEqual([
          [lex.TokenType.TEXT, 'a'],
          [lex.TokenType.EOF, ''],
        ]);
      });
      it('should allow "<" in text nodes', () => {
        expect(tokenizeAndHumanizeParts('{{ a < b ? c : d }}')).toEqual([
          [lex.TokenType.TEXT, '{{ a < b ? c : d }}'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeSourceSpans('a')).toEqual([
          [lex.TokenType.TAG_OPEN_START, '
'],
          [lex.TokenType.TEXT, 'a'],
          [lex.TokenType.EOF, ''],
        ]);
        expect(tokenizeAndHumanizeParts('< a>')).toEqual([
          [lex.TokenType.TEXT, '< a>'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should parse valid start tag in interpolation', () => {
        expect(tokenizeAndHumanizeParts('{{ a  d }}')).toEqual([
          [lex.TokenType.TEXT, '{{ a '],
          [lex.TokenType.TAG_OPEN_START, '', 'b'],
          [lex.TokenType.ATTR_NAME, '', '&&'],
          [lex.TokenType.ATTR_NAME, '', 'c'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TEXT, ' d }}'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should be able to escape {', () => {
        expect(tokenizeAndHumanizeParts('{{ "{" }}')).toEqual([
          [lex.TokenType.TEXT, '{{ "{" }}'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should be able to escape {{', () => {
        expect(tokenizeAndHumanizeParts('{{ "{{" }}')).toEqual([
          [lex.TokenType.TEXT, '{{ "{{" }}'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should treat expansion form as text when they are not parsed', () => {
        expect(tokenizeAndHumanizeParts(
                   '{a, b, =4 {c}}', {tokenizeExpansionForms: false}))
            .toEqual([
              [lex.TokenType.TAG_OPEN_START, '', 'span'],
              [lex.TokenType.TAG_OPEN_END],
              [lex.TokenType.TEXT, '{a, b, =4 {c}}'],
              [lex.TokenType.TAG_CLOSE, '', 'span'],
              [lex.TokenType.EOF],
            ]);
      });
    });
    describe('raw text', () => {
      it('should parse text', () => {
        expect(tokenizeAndHumanizeParts(``)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'script'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.RAW_TEXT, 't\ne\ns\nt'],
          [lex.TokenType.TAG_CLOSE, '', 'script'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should not detect entities', () => {
        expect(tokenizeAndHumanizeParts(``)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'script'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.RAW_TEXT, '&'],
          [lex.TokenType.TAG_CLOSE, '', 'script'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should ignore other opening tags', () => {
        expect(tokenizeAndHumanizeParts(``)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'script'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.RAW_TEXT, 'a'],
          [lex.TokenType.TAG_CLOSE, '', 'script'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should ignore other closing tags', () => {
        expect(tokenizeAndHumanizeParts(``)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'script'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.RAW_TEXT, 'a'],
          [lex.TokenType.TAG_CLOSE, '', 'script'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should store the locations', () => {
        expect(tokenizeAndHumanizeSourceSpans(``)).toEqual([
          [lex.TokenType.TAG_OPEN_START, ''],
          [lex.TokenType.EOF, ''],
        ]);
      });
    });
    describe('escapable raw text', () => {
      it('should parse text', () => {
        expect(tokenizeAndHumanizeParts(`
t\ne\rs\r\nt`)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'title'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.ESCAPABLE_RAW_TEXT, 't\ne\ns\nt'],
          [lex.TokenType.TAG_CLOSE, '', 'title'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should detect entities', () => {
        expect(tokenizeAndHumanizeParts(`
&`)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'title'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.ESCAPABLE_RAW_TEXT, '&'],
          [lex.TokenType.TAG_CLOSE, '', 'title'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should ignore other opening tags', () => {
        expect(tokenizeAndHumanizeParts(`
a`)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'title'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.ESCAPABLE_RAW_TEXT, 'a
'],
          [lex.TokenType.TAG_CLOSE, '', 'title'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should ignore other closing tags', () => {
        expect(tokenizeAndHumanizeParts(`
a`)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'title'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.ESCAPABLE_RAW_TEXT, 'a'],
          [lex.TokenType.TAG_CLOSE, '', 'title'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should store the locations', () => {
        expect(tokenizeAndHumanizeSourceSpans(`
a`)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '
'],
          [lex.TokenType.ESCAPABLE_RAW_TEXT, 'a'],
          [lex.TokenType.TAG_CLOSE, ''],
          [lex.TokenType.EOF, ''],
        ]);
      });
    });
    describe('expansion forms', () => {
      it('should parse an expansion form', () => {
        expect(
            tokenizeAndHumanizeParts(
                '{one.two, three, =4 {four} =5 {five} foo {bar} }', {tokenizeExpansionForms: true}))
            .toEqual([
              [lex.TokenType.EXPANSION_FORM_START],
              [lex.TokenType.RAW_TEXT, 'one.two'],
              [lex.TokenType.RAW_TEXT, 'three'],
              [lex.TokenType.EXPANSION_CASE_VALUE, '=4'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.TEXT, 'four'],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_CASE_VALUE, '=5'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.TEXT, 'five'],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_CASE_VALUE, 'foo'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.TEXT, 'bar'],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_FORM_END],
              [lex.TokenType.EOF],
            ]);
      });
      it('should parse an expansion form with text elements surrounding it', () => {
        expect(tokenizeAndHumanizeParts(
                   'before{one.two, three, =4 {four}}after', {tokenizeExpansionForms: true}))
            .toEqual([
              [lex.TokenType.TEXT, 'before'],
              [lex.TokenType.EXPANSION_FORM_START],
              [lex.TokenType.RAW_TEXT, 'one.two'],
              [lex.TokenType.RAW_TEXT, 'three'],
              [lex.TokenType.EXPANSION_CASE_VALUE, '=4'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.TEXT, 'four'],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_FORM_END],
              [lex.TokenType.TEXT, 'after'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should parse an expansion form as a tag single child', () => {
        expect(tokenizeAndHumanizeParts(
                   '
{a, b, =4 {c}}
', {tokenizeExpansionForms: true}))
            .toEqual([
              [lex.TokenType.TAG_OPEN_START, '', 'div'],
              [lex.TokenType.TAG_OPEN_END],
              [lex.TokenType.TAG_OPEN_START, '', 'span'],
              [lex.TokenType.TAG_OPEN_END],
              [lex.TokenType.EXPANSION_FORM_START],
              [lex.TokenType.RAW_TEXT, 'a'],
              [lex.TokenType.RAW_TEXT, 'b'],
              [lex.TokenType.EXPANSION_CASE_VALUE, '=4'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.TEXT, 'c'],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_FORM_END],
              [lex.TokenType.TAG_CLOSE, '', 'span'],
              [lex.TokenType.TAG_CLOSE, '', 'div'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should parse an expansion forms with elements in it', () => {
        expect(tokenizeAndHumanizeParts(
                   '{one.two, three, =4 {four 
a}}', {tokenizeExpansionForms: true}))
            .toEqual([
              [lex.TokenType.EXPANSION_FORM_START],
              [lex.TokenType.RAW_TEXT, 'one.two'],
              [lex.TokenType.RAW_TEXT, 'three'],
              [lex.TokenType.EXPANSION_CASE_VALUE, '=4'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.TEXT, 'four '],
              [lex.TokenType.TAG_OPEN_START, '', 'b'],
              [lex.TokenType.TAG_OPEN_END],
              [lex.TokenType.TEXT, 'a'],
              [lex.TokenType.TAG_CLOSE, '', 'b'],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_FORM_END],
              [lex.TokenType.EOF],
            ]);
      });
      it('should parse an expansion forms containing an interpolation', () => {
        expect(tokenizeAndHumanizeParts(
                   '{one.two, three, =4 {four {{a}}}}', {tokenizeExpansionForms: true}))
            .toEqual([
              [lex.TokenType.EXPANSION_FORM_START],
              [lex.TokenType.RAW_TEXT, 'one.two'],
              [lex.TokenType.RAW_TEXT, 'three'],
              [lex.TokenType.EXPANSION_CASE_VALUE, '=4'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.TEXT, 'four {{a}}'],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_FORM_END],
              [lex.TokenType.EOF],
            ]);
      });
      it('should parse nested expansion forms', () => {
        expect(tokenizeAndHumanizeParts(
                   `{one.two, three, =4 { {xx, yy, =x {one}} }}`, {tokenizeExpansionForms: true}))
            .toEqual([
              [lex.TokenType.EXPANSION_FORM_START],
              [lex.TokenType.RAW_TEXT, 'one.two'],
              [lex.TokenType.RAW_TEXT, 'three'],
              [lex.TokenType.EXPANSION_CASE_VALUE, '=4'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.EXPANSION_FORM_START],
              [lex.TokenType.RAW_TEXT, 'xx'],
              [lex.TokenType.RAW_TEXT, 'yy'],
              [lex.TokenType.EXPANSION_CASE_VALUE, '=x'],
              [lex.TokenType.EXPANSION_CASE_EXP_START],
              [lex.TokenType.TEXT, 'one'],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_FORM_END],
              [lex.TokenType.TEXT, ' '],
              [lex.TokenType.EXPANSION_CASE_EXP_END],
              [lex.TokenType.EXPANSION_FORM_END],
              [lex.TokenType.EOF],
            ]);
      });
    });
    describe('errors', () => {
      it('should report unescaped "{" on error', () => {
        expect(tokenizeAndHumanizeErrors(`
before { after
`, {tokenizeExpansionForms: true}))
            .toEqual([[
              lex.TokenType.RAW_TEXT,
              `Unexpected character "EOF" (Do you have an unescaped "{" in your template? Use "{{ '{' }}") to escape it.)`,
              '0:21',
            ]]);
      });
      it('should include 2 lines of context in message', () => {
        const src = '111\n222\n333\nE\n444\n555\n666\n';
        const file = new ParseSourceFile(src, 'file://');
        const location = new ParseLocation(file, 12, 123, 456);
        const span = new ParseSourceSpan(location, location);
        const error = new lex.TokenError('**ERROR**', null !, span);
        expect(error.toString())
            .toEqual(`**ERROR** ("\n222\n333\n[ERROR ->]E\n444\n555\n"): file://@123:456`);
      });
    });
    describe('unicode characters', () => {
      it('should support unicode characters', () => {
        expect(tokenizeAndHumanizeSourceSpans(`
İ
`)).toEqual([
          [lex.TokenType.TAG_OPEN_START, '
'],
          [lex.TokenType.TEXT, 'İ'],
          [lex.TokenType.TAG_CLOSE, '
'],
          [lex.TokenType.EOF, ''],
        ]);
      });
    });
    describe('(processing escaped strings)', () => {
      it('should unescape standard escape sequences', () => {
        expect(tokenizeAndHumanizeParts('\\\' \\\' \\\'', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\' \' \''],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\" \\" \\"', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\" \" \"'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\` \\` \\`', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\` \` \`'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\\\ \\\\ \\\\', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\\ \\ \\'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\n \\n \\n', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\n \n \n'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\r \\r \\r', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\n \n \n'],  // post processing converts `\r` to `\n`
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\v \\v \\v', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\v \v \v'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\t \\t \\t', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\t \t \t'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\b \\b \\b', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\b \b \b'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\f \\f \\f', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\f \f \f'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts(
                   '\\\' \\" \\` \\\\ \\n \\r \\v \\t \\b \\f', {escapedString: true}))
            .toEqual([
              [lex.TokenType.TEXT, '\' \" \` \\ \n \n \v \t \b \f'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should unescape null sequences', () => {
        expect(tokenizeAndHumanizeParts('\\0', {escapedString: true})).toEqual([
          [lex.TokenType.EOF],
        ]);
        // \09 is not an octal number so the \0 is taken as EOF
        expect(tokenizeAndHumanizeParts('\\09', {escapedString: true})).toEqual([
          [lex.TokenType.EOF],
        ]);
      });
      it('should unescape octal sequences', () => {
        // \19 is read as an octal `\1` followed by a normal char `9`
        // \1234 is read as an octal `\123` followed by a normal char `4`
        // \999 is not an octal number so its backslash just gets removed.
        expect(tokenizeAndHumanizeParts(
                   '\\001 \\01 \\1 \\12 \\223 \\19 \\2234 \\999', {escapedString: true}))
            .toEqual([
              [lex.TokenType.TEXT, '\x01 \x01 \x01 \x0A \x93 \x019 \x934 999'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should unescape hex sequences', () => {
        expect(tokenizeAndHumanizeParts('\\x12 \\x4F \\xDC', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\x12 \x4F \xDC'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should report an error on an invalid hex sequence', () => {
        expect(tokenizeAndHumanizeErrors('\\xGG', {escapedString: true})).toEqual([
          [null, 'Invalid hexadecimal escape sequence', '0:2']
        ]);
        expect(tokenizeAndHumanizeErrors('abc \\x xyz', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, 'Invalid hexadecimal escape sequence', '0:6']
        ]);
        expect(tokenizeAndHumanizeErrors('abc\\x', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, 'Unexpected character "EOF"', '0:5']
        ]);
      });
      it('should unescape fixed length Unicode sequences', () => {
        expect(tokenizeAndHumanizeParts('\\u0123 \\uABCD', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, '\u0123 \uABCD'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should error on an invalid fixed length Unicode sequence', () => {
        expect(tokenizeAndHumanizeErrors('\\uGGGG', {escapedString: true})).toEqual([
          [null, 'Invalid hexadecimal escape sequence', '0:2']
        ]);
      });
      it('should unescape variable length Unicode sequences', () => {
        expect(tokenizeAndHumanizeParts(
                   '\\u{01} \\u{ABC} \\u{1234} \\u{123AB}', {escapedString: true}))
            .toEqual([
              [lex.TokenType.TEXT, '\u{01} \u{ABC} \u{1234} \u{123AB}'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should error on an invalid variable length Unicode sequence', () => {
        expect(tokenizeAndHumanizeErrors('\\u{GG}', {escapedString: true})).toEqual([
          [null, 'Invalid hexadecimal escape sequence', '0:3']
        ]);
      });
      it('should unescape line continuations', () => {
        expect(tokenizeAndHumanizeParts('abc\\\ndef', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, 'abcdef'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeParts('\\\nx\\\ny\\\n', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, 'xy'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should remove backslash from "non-escape" sequences', () => {
        expect(tokenizeAndHumanizeParts('\a \g \~', {escapedString: true})).toEqual([
          [lex.TokenType.TEXT, 'a g ~'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should unescape sequences in plain text', () => {
        expect(tokenizeAndHumanizeParts('abc\ndef\\nghi\\tjkl\\`\\\'\\"mno', {escapedString: true}))
            .toEqual([
              [lex.TokenType.TEXT, 'abc\ndef\nghi\tjkl`\'"mno'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should unescape sequences in raw text', () => {
        expect(tokenizeAndHumanizeParts(
                   '', {escapedString: true}))
            .toEqual([
              [lex.TokenType.TAG_OPEN_START, '', 'script'],
              [lex.TokenType.TAG_OPEN_END],
              [lex.TokenType.RAW_TEXT, 'abc\ndef\nghi\tjkl`\'"mno'],
              [lex.TokenType.TAG_CLOSE, '', 'script'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should unescape sequences in escapable raw text', () => {
        expect(tokenizeAndHumanizeParts(
                   '
abc\ndef\\nghi\\tjkl\\`\\\'\\"mno', {escapedString: true}))
            .toEqual([
              [lex.TokenType.TAG_OPEN_START, '', 'title'],
              [lex.TokenType.TAG_OPEN_END],
              [lex.TokenType.ESCAPABLE_RAW_TEXT, 'abc\ndef\nghi\tjkl`\'"mno'],
              [lex.TokenType.TAG_CLOSE, '', 'title'],
              [lex.TokenType.EOF],
            ]);
      });
      it('should parse over escape sequences in tag definitions', () => {
        expect(tokenizeAndHumanizeParts('
', {escapedString: true}))
            .toEqual([
              [lex.TokenType.TAG_OPEN_START, '', 't'],
              [lex.TokenType.ATTR_NAME, '', 'a'],
              [lex.TokenType.ATTR_QUOTE, '"'],
              [lex.TokenType.ATTR_VALUE, 'b'],
              [lex.TokenType.ATTR_QUOTE, '"'],
              [lex.TokenType.ATTR_NAME, '', 'c'],
              [lex.TokenType.ATTR_QUOTE, '\''],
              [lex.TokenType.ATTR_VALUE, 'd'],
              [lex.TokenType.ATTR_QUOTE, '\''],
              [lex.TokenType.TAG_OPEN_END],
              [lex.TokenType.EOF],
            ]);
      });
      it('should parse over escaped new line in tag definitions', () => {
        const text = '';
        expect(tokenizeAndHumanizeParts(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 't'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TAG_CLOSE, '', 't'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should parse over escaped characters in tag definitions', () => {
        const text = '';
        expect(tokenizeAndHumanizeParts(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 't'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TAG_CLOSE, '', 't'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should unescape characters in tag names', () => {
        const text = '';
        expect(tokenizeAndHumanizeParts(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 'td'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TAG_CLOSE, '', 'td'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeSourceSpans(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, ''],
          [lex.TokenType.TAG_CLOSE, ''],
          [lex.TokenType.EOF, ''],
        ]);
      });
      it('should unescape characters in attributes', () => {
        const text = '';
        expect(tokenizeAndHumanizeParts(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 't'],
          [lex.TokenType.ATTR_NAME, '', 'd'],
          [lex.TokenType.ATTR_QUOTE, '"'],
          [lex.TokenType.ATTR_VALUE, 'e'],
          [lex.TokenType.ATTR_QUOTE, '"'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TAG_CLOSE, '', 't'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should parse over escaped new line in attribute values', () => {
        const text = '';
        expect(tokenizeAndHumanizeParts(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 't'],
          [lex.TokenType.ATTR_NAME, '', 'a'],
          [lex.TokenType.ATTR_VALUE, 'b'],
          [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TAG_CLOSE, '', 't'],
          [lex.TokenType.EOF],
        ]);
      });
      it('should tokenize the correct span when there are escape sequences', () => {
        const text =
            'selector: "app-root",\ntemplate: "line 1\\n\\"line 2\\"\\nline 3",\ninputs: []';
        const range = {
          startPos: 33,
          startLine: 1,
          startCol: 10,
          endPos: 59,
        };
        expect(tokenizeAndHumanizeParts(text, {range, escapedString: true})).toEqual([
          [lex.TokenType.TEXT, 'line 1\n"line 2"\nline 3'],
          [lex.TokenType.EOF],
        ]);
        expect(tokenizeAndHumanizeSourceSpans(text, {range, escapedString: true})).toEqual([
          [lex.TokenType.TEXT, 'line 1\\n\\"line 2\\"\\nline 3'],
          [lex.TokenType.EOF, ''],
        ]);
      });
      it('should account for escape sequences when computing source spans ', () => {
        const text = 'line 1\n' +  // <- unescaped line break
            'line 2\\n' +          // <- escaped line break
            'line 3\\\n' +             // <- line continuation
            '';
        expect(tokenizeAndHumanizeParts(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, '', 't'], [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TEXT, 'line 1'], [lex.TokenType.TAG_CLOSE, '', 't'],
          [lex.TokenType.TEXT, '\n'],
          [lex.TokenType.TAG_OPEN_START, '', 't'], [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TEXT, 'line 2'], [lex.TokenType.TAG_CLOSE, '', 't'],
          [lex.TokenType.TEXT, '\n'],
          [lex.TokenType.TAG_OPEN_START, '', 't'], [lex.TokenType.TAG_OPEN_END],
          [lex.TokenType.TEXT, 'line 3'],  // <- line continuation does not appear in token
          [lex.TokenType.TAG_CLOSE, '', 't'],
          [lex.TokenType.EOF]
        ]);
        expect(tokenizeAndHumanizeLineColumn(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, '0:0'],
          [lex.TokenType.TAG_OPEN_END, '0:2'],
          [lex.TokenType.TEXT, '0:3'],
          [lex.TokenType.TAG_CLOSE, '0:9'],
          [lex.TokenType.TEXT, '0:13'],  // <- real newline increments the row
          [lex.TokenType.TAG_OPEN_START, '1:0'],
          [lex.TokenType.TAG_OPEN_END, '1:2'],
          [lex.TokenType.TEXT, '1:3'],
          [lex.TokenType.TAG_CLOSE, '1:9'],
          [lex.TokenType.TEXT, '1:13'],  // <- escaped newline does not increment the row
          [lex.TokenType.TAG_OPEN_START, '1:15'],
          [lex.TokenType.TAG_OPEN_END, '1:17'],
          [lex.TokenType.TEXT, '1:18'],  // <- the line continuation increments the row
          [lex.TokenType.TAG_CLOSE, '2:0'],
          [lex.TokenType.EOF, '2:4'],
        ]);
        expect(tokenizeAndHumanizeSourceSpans(text, {escapedString: true})).toEqual([
          [lex.TokenType.TAG_OPEN_START, ''],
          [lex.TokenType.TEXT, 'line 1'], [lex.TokenType.TAG_CLOSE, ''],
          [lex.TokenType.TEXT, '\n'],
          [lex.TokenType.TAG_OPEN_START, ''],
          [lex.TokenType.TEXT, 'line 2'], [lex.TokenType.TAG_CLOSE, ''],
          [lex.TokenType.TEXT, '\\n'],
          [lex.TokenType.TAG_OPEN_START, ''],
          [lex.TokenType.TEXT, 'line 3\\\n'], [lex.TokenType.TAG_CLOSE, ''],
          [lex.TokenType.EOF, '']
        ]);
      });
    });
  });
}
function tokenizeWithoutErrors(input: string, options?: lex.TokenizeOptions): lex.Token[] {
  const tokenizeResult = lex.tokenize(input, 'someUrl', getHtmlTagDefinition, options);
  if (tokenizeResult.errors.length > 0) {
    const errorString = tokenizeResult.errors.join('\n');
    throw new Error(`Unexpected parse errors:\n${errorString}`);
  }
  return tokenizeResult.tokens;
}
function tokenizeAndHumanizeParts(input: string, options?: lex.TokenizeOptions): any[] {
  return tokenizeWithoutErrors(input, options).map(token => [token.type].concat(token.parts));
}
function tokenizeAndHumanizeSourceSpans(input: string, options?: lex.TokenizeOptions): any[] {
  return tokenizeWithoutErrors(input, options)
      .map(token => [token.type, token.sourceSpan.toString()]);
}
function humanizeLineColumn(location: ParseLocation): string {
  return `${location.line}:${location.col}`;
}
function tokenizeAndHumanizeLineColumn(input: string, options?: lex.TokenizeOptions): any[] {
  return tokenizeWithoutErrors(input, options)
      .map(token => [token.type, humanizeLineColumn(token.sourceSpan.start)]);
}
function tokenizeAndHumanizeErrors(input: string, options?: lex.TokenizeOptions): any[] {
  return lex.tokenize(input, 'someUrl', getHtmlTagDefinition, options)
      .errors.map(e => [e.tokenType, e.msg, humanizeLineColumn(e.span.start)]);
}