pdf.js/test/unit/parser_spec.js

/* Copyright 2017 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* eslint no-var: error */

import { Lexer, Linearization, Parser } from '../../src/core/parser';
import { FormatError } from '../../src/shared/util';
import { Name } from '../../src/core/primitives';
import { StringStream } from '../../src/core/stream';

describe('parser', function() {
  describe('Parser', function() {
    describe('inlineStreamSkipEI', function() {
      it('should skip over the EI marker if it is found', function() {
        const string = 'q 1 0 0 1 0 0 cm BI /W 10 /H 10 /BPC 1 ' +
                       '/F /A85 ID abc123~> EI Q';
        const input = new StringStream(string);
        const parser = new Parser({
          lexer: new Lexer(input),
          xref: null,
          allowStreams: true,
        });

        parser.inlineStreamSkipEI(input);
        expect(input.pos).toEqual(string.indexOf('Q'));
        expect(input.peekByte()).toEqual(0x51); // 'Q'
      });

      it('should skip to the end of stream if the EI marker is not found',
          function() {
        const string = 'q 1 0 0 1 0 0 cm BI /W 10 /H 10 /BPC 1 ' +
                       '/F /A85 ID abc123~> Q';
        const input = new StringStream(string);
        const parser = new Parser({
          lexer: new Lexer(input),
          xref: null,
          allowStreams: true,
        });

        parser.inlineStreamSkipEI(input);
        expect(input.pos).toEqual(string.length);
        expect(input.peekByte()).toEqual(-1);
      });
    });
  });

  describe('Lexer', function() {
    describe('nextChar', function() {
      it('should return and set -1 when the end of the stream is reached',
          function() {
        const input = new StringStream('');
        const lexer = new Lexer(input);
        expect(lexer.nextChar()).toEqual(-1);
        expect(lexer.currentChar).toEqual(-1);
      });

      it('should return and set the character after the current position',
          function() {
        const input = new StringStream('123');
        const lexer = new Lexer(input);
        expect(lexer.nextChar()).toEqual(0x32); // '2'
        expect(lexer.currentChar).toEqual(0x32); // '2'
      });
    });

    describe('peekChar', function() {
      it('should only return -1 when the end of the stream is reached',
          function() {
        const input = new StringStream('');
        const lexer = new Lexer(input);
        expect(lexer.peekChar()).toEqual(-1);
        expect(lexer.currentChar).toEqual(-1);
      });

      it('should only return the character after the current position',
          function() {
        const input = new StringStream('123');
        const lexer = new Lexer(input);
        expect(lexer.peekChar()).toEqual(0x32); // '2'
        expect(lexer.currentChar).toEqual(0x31); // '1'
      });
    });

    describe('getNumber', function() {
      it('should stop parsing numbers at the end of stream', function() {
        const input = new StringStream('11.234');
        const lexer = new Lexer(input);
        expect(lexer.getNumber()).toEqual(11.234);
      });

      it('should parse PostScript numbers', function() {
        const numbers = ['-.002', '34.5', '-3.62', '123.6e10', '1E-5', '-1.',
                         '0.0', '123', '-98', '43445', '0', '+17'];
        for (const number of numbers) {
          const input = new StringStream(number);
          const lexer = new Lexer(input);

          const result = lexer.getNumber(), expected = parseFloat(number);

          if (result !== expected && Math.abs(result - expected) < 1e-15) {
            console.error(`Fuzzy matching "${result}" with "${expected}" to ` +
                          'work-around rounding bugs in Chromium browsers.');

            expect(true).toEqual(true);
            continue;
          }
          expect(result).toEqual(expected);
        }
      });

      it('should ignore double negative before number', function() {
        const input = new StringStream('--205.88');
        const lexer = new Lexer(input);
        expect(lexer.getNumber()).toEqual(-205.88);
      });

      it('should ignore minus signs in the middle of number', function() {
        const input = new StringStream('205--.88');
        const lexer = new Lexer(input);
        expect(lexer.getNumber()).toEqual(205.88);
      });

      it('should ignore line-breaks between operator and digit in number',
          function() {
        const minusInput = new StringStream('-\r\n205.88');
        const minusLexer = new Lexer(minusInput);
        expect(minusLexer.getNumber()).toEqual(-205.88);

        const plusInput = new StringStream('+\r\n205.88');
        const plusLexer = new Lexer(plusInput);
        expect(plusLexer.getNumber()).toEqual(205.88);
      });

      it('should treat a single decimal point as zero', function() {
        const input = new StringStream('.');
        const lexer = new Lexer(input);
        expect(lexer.getNumber()).toEqual(0);

        const numbers = ['..', '-.', '+.', '-\r\n.', '+\r\n.'];
        for (const number of numbers) {
          const input = new StringStream(number);
          const lexer = new Lexer(input);

          expect(function() {
            return lexer.getNumber();
          }).toThrowError(FormatError, /^Invalid number:\s/);
        }
      });

      it('should handle glued numbers and operators', function() {
        const input = new StringStream('123ET');
        const lexer = new Lexer(input);
        expect(lexer.getNumber()).toEqual(123);
        // The lexer must not have consumed the 'E'
        expect(lexer.currentChar).toEqual(0x45); // 'E'
      });
    });

    describe('getString', function() {
      it('should stop parsing strings at the end of stream', function() {
        const input = new StringStream('(1$4)');
        input.getByte = function(super_getByte) {
          // Simulating end of file using null (see issue 2766).
          const ch = super_getByte.call(input);
          return (ch === 0x24 /* '$' */ ? -1 : ch);
        }.bind(input, input.getByte);
        const lexer = new Lexer(input);
        expect(lexer.getString()).toEqual('1');
      });

      it('should ignore escaped CR and LF', function() {
        // '(\101\<CR><LF>\102)' should be parsed as 'AB'.
        const input = new StringStream('(\\101\\\r\n\\102\\\r\\103\\\n\\104)');
        const lexer = new Lexer(input);
        expect(lexer.getString()).toEqual('ABCD');
      });
    });

    describe('getHexString', function() {
      it('should not throw exception on bad input', function() {
        // '7 0 2 15 5 2 2 2 4 3 2 4' should be parsed as '70 21 55 22 24 32'.
        const input = new StringStream('<7 0 2 15 5 2 2 2 4 3 2 4>');
        const lexer = new Lexer(input);
        expect(lexer.getHexString()).toEqual('p!U"$2');
      });
    });

    describe('getName', function() {
      it('should handle Names with invalid usage of NUMBER SIGN (#)',
          function() {
        const inputNames = ['/# 680 0 R', '/#AQwerty', '/#A<</B'];
        const expectedNames = ['#', '#AQwerty', '#A'];

        for (let i = 0, ii = inputNames.length; i < ii; i++) {
          const input = new StringStream(inputNames[i]);
          const lexer = new Lexer(input);
          expect(lexer.getName()).toEqual(Name.get(expectedNames[i]));
        }
      });
    });
  });

  describe('Linearization', function() {
    it('should not find a linearization dictionary', function() {
      // Not an actual linearization dictionary.
      const stream1 = new StringStream(
        '3 0 obj\n' +
        '<<\n' +
        '/Length 4622\n' +
        '/Filter /FlateDecode\n' +
        '>>\n' +
        'endobj'
      );
      expect(Linearization.create(stream1)).toEqual(null);

      // Linearization dictionary with invalid version number.
      const stream2 = new StringStream(
        '1 0 obj\n' +
        '<<\n' +
        '/Linearized 0\n' +
        '>>\n' +
        'endobj'
      );
      expect(Linearization.create(stream2)).toEqual(null);
    });

    it('should accept a valid linearization dictionary', function() {
      const stream = new StringStream(
        '131 0 obj\n' +
        '<<\n' +
        '/Linearized 1\n' +
        '/O 133\n' +
        '/H [ 1388 863 ]\n' +
        '/L 90\n' +
        '/E 43573\n' +
        '/N 18\n' +
        '/T 193883\n' +
        '>>\n' +
        'endobj'
      );
      const expectedLinearizationDict = {
        length: 90,
        hints: [1388, 863],
        objectNumberFirst: 133,
        endFirst: 43573,
        numPages: 18,
        mainXRefEntriesOffset: 193883,
        pageFirst: 0,
      };
      expect(Linearization.create(stream)).toEqual(expectedLinearizationDict);
    });

    it('should reject a linearization dictionary with invalid ' +
       'integer parameters', function() {
      // The /L parameter should be equal to the stream length.
      const stream1 = new StringStream(
        '1 0 obj\n' +
        '<<\n' +
        '/Linearized 1\n' +
        '/O 133\n' +
        '/H [ 1388 863 ]\n' +
        '/L 196622\n' +
        '/E 43573\n' +
        '/N 18\n' +
        '/T 193883\n' +
        '>>\n' +
        'endobj'
      );
      expect(function() {
        return Linearization.create(stream1);
      }).toThrow(new Error('The "L" parameter in the linearization ' +
                           'dictionary does not equal the stream length.'));

      // The /E parameter should not be zero.
      const stream2 = new StringStream(
        '1 0 obj\n' +
        '<<\n' +
        '/Linearized 1\n' +
        '/O 133\n' +
        '/H [ 1388 863 ]\n' +
        '/L 84\n' +
        '/E 0\n' +
        '/N 18\n' +
        '/T 193883\n' +
        '>>\n' +
        'endobj'
      );
      expect(function() {
        return Linearization.create(stream2);
      }).toThrow(new Error('The "E" parameter in the linearization ' +
                           'dictionary is invalid.'));

      // The /O parameter should be an integer.
      const stream3 = new StringStream(
        '1 0 obj\n' +
        '<<\n' +
        '/Linearized 1\n' +
        '/O /abc\n' +
        '/H [ 1388 863 ]\n' +
        '/L 89\n' +
        '/E 43573\n' +
        '/N 18\n' +
        '/T 193883\n' +
        '>>\n' +
        'endobj'
      );
      expect(function() {
        return Linearization.create(stream3);
      }).toThrow(new Error('The "O" parameter in the linearization ' +
                           'dictionary is invalid.'));
    });

    it('should reject a linearization dictionary with invalid hint parameters',
       function() {
      // The /H parameter should be an array.
      const stream1 = new StringStream(
        '1 0 obj\n' +
        '<<\n' +
        '/Linearized 1\n' +
        '/O 133\n' +
        '/H 1388\n' +
        '/L 80\n' +
        '/E 43573\n' +
        '/N 18\n' +
        '/T 193883\n' +
        '>>\n' +
        'endobj'
      );
      expect(function() {
        return Linearization.create(stream1);
      }).toThrow(new Error('Hint array in the linearization dictionary ' +
                           'is invalid.'));

      // The hint array should contain two, or four, elements.
      const stream2 = new StringStream(
        '1 0 obj\n' +
        '<<\n' +
        '/Linearized 1\n' +
        '/O 133\n' +
        '/H [ 1388 ]\n' +
        '/L 84\n' +
        '/E 43573\n' +
        '/N 18\n' +
        '/T 193883\n' +
        '>>\n' +
        'endobj'
      );
      expect(function() {
        return Linearization.create(stream2);
      }).toThrow(new Error('Hint array in the linearization dictionary ' +
                           'is invalid.'));

      // The hint array should not contain zero.
      const stream3 = new StringStream(
        '1 0 obj\n' +
        '<<\n' +
        '/Linearized 1\n' +
        '/O 133\n' +
        '/H [ 1388 863 0 234]\n' +
        '/L 93\n' +
        '/E 43573\n' +
        '/N 18\n' +
        '/T 193883\n' +
        '>>\n' +
        'endobj'
      );
      expect(function() {
        return Linearization.create(stream3);
      }).toThrow(new Error('Hint (2) in the linearization dictionary ' +
                           'is invalid.'));
    });
  });
});