pdfjs-dist/lib/test/unit/stream_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.
 */
'use strict';

var corePrimitives = require('../../core/primitives.js');
var coreStream = require('../../core/stream.js');
var Dict = corePrimitives.Dict;
var Stream = coreStream.Stream;
var PredictorStream = coreStream.PredictorStream;
describe('stream', function () {
  beforeEach(function () {
    jasmine.addMatchers({
      toMatchTypedArray: function toMatchTypedArray(util, customEqualityTesters) {
        return {
          compare: function compare(actual, expected) {
            var result = {};
            if (actual.length !== expected.length) {
              result.pass = false;
              result.message = 'Array length: ' + actual.length + ', expected: ' + expected.length;
              return result;
            }
            result.pass = true;
            for (var i = 0, ii = expected.length; i < ii; i++) {
              var a = actual[i],
                  b = expected[i];
              if (a !== b) {
                result.pass = false;
                break;
              }
            }
            return result;
          }
        };
      }
    });
  });
  describe('PredictorStream', function () {
    it('should decode simple predictor data', function () {
      var dict = new Dict();
      dict.set('Predictor', 12);
      dict.set('Colors', 1);
      dict.set('BitsPerComponent', 8);
      dict.set('Columns', 2);
      var input = new Stream(new Uint8Array([2, 100, 3, 2, 1, 255, 2, 1, 255]), 0, 9, dict);
      var predictor = new PredictorStream(input, 9, dict);
      var result = predictor.getBytes(6);
      expect(result).toMatchTypedArray(new Uint8Array([100, 3, 101, 2, 102, 1]));
    });
  });
});