pdfjs-dist/lib/test/unit/stream_spec.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2021 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.
 *
 * @licend The above is the entire license notice for the
 * Javascript code in this page
 */
"use strict";

var _primitives = require("../../core/primitives.js");

var _predictor_stream = require("../../core/predictor_stream.js");

var _stream = require("../../core/stream.js");

describe("stream", function () {
  beforeEach(function () {
    jasmine.addMatchers({
      toMatchTypedArray(util, customEqualityTesters) {
        return {
          compare(actual, expected) {
            const result = {};

            if (actual.length !== expected.length) {
              result.pass = false;
              result.message = "Array length: " + actual.length + ", expected: " + expected.length;
              return result;
            }

            result.pass = true;

            for (let i = 0, ii = expected.length; i < ii; i++) {
              const 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 () {
      const dict = new _primitives.Dict();
      dict.set("Predictor", 12);
      dict.set("Colors", 1);
      dict.set("BitsPerComponent", 8);
      dict.set("Columns", 2);
      const input = new _stream.Stream(new Uint8Array([2, 100, 3, 2, 1, 255, 2, 1, 255]), 0, 9, dict);
      const predictor = new _predictor_stream.PredictorStream(input, 9, dict);
      const result = predictor.getBytes(6);
      expect(result).toMatchTypedArray(new Uint8Array([100, 3, 101, 2, 102, 1]));
      predictor.reset();
      const clampedResult = predictor.getBytes(6, true);
      expect(clampedResult).toEqual(new Uint8ClampedArray([100, 3, 101, 2, 102, 1]));
    });
  });
});