tests/test.deflator.js

   1 /* eslint-disable no-console */
   2 const expect = chai.expect;
   3
   4 import { inflateInit, inflate } from "../vendor/pako/lib/zlib/inflate.js";
   5 import ZStream from "../vendor/pako/lib/zlib/zstream.js";
   6 import Deflator from "../core/deflator.js";
   7
   8 function _inflator(compText, expected) {
   9     let strm = new ZStream();
  10     let chunkSize = 1024 * 10 * 10;
  11     strm.output = new Uint8Array(chunkSize);
  12
  13     inflateInit(strm, 5);
  14
  15     if (expected > chunkSize) {
  16         chunkSize = expected;
  17         strm.output = new Uint8Array(chunkSize);
  18     }
  19
  20     /* eslint-disable camelcase */
  21     strm.input = compText;
  22     strm.avail_in = strm.input.length;
  23     strm.next_in = 0;
  24
  25     strm.next_out = 0;
  26     strm.avail_out = expected.length;
  27     /* eslint-enable camelcase */
  28
  29     let ret = inflate(strm, 0);
  30
  31     // Check that return code is not an error
  32     expect(ret).to.be.greaterThan(-1);
  33
  34     return new Uint8Array(strm.output.buffer, 0, strm.next_out);
  35 }
  36
  37 describe('Deflate data', function () {
  38
  39     it('should be able to deflate messages', function () {
  40         let deflator = new Deflator();
  41
  42         let text = "123asdf";
  43         let preText = new Uint8Array(text.length);
  44         for (let i = 0; i < preText.length; i++) {
  45             preText[i] = text.charCodeAt(i);
  46         }
  47
  48         let compText = deflator.deflate(preText);
  49
  50         let inflatedText = _inflator(compText, text.length);
  51         expect(inflatedText).to.array.equal(preText);
  52
  53     });
  54
  55     it('should be able to deflate large messages', function () {
  56         let deflator = new Deflator();
  57
  58         /* Generate a big string with random characters. Used because
  59            repetition of letters might be deflated more effectively than
  60            random ones. */
  61         let text = "";
  62         let characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  63         for (let i = 0; i < 300000; i++) {
  64             text += characters.charAt(Math.floor(Math.random() * characters.length));
  65         }
  66
  67         let preText = new Uint8Array(text.length);
  68         for (let i = 0; i < preText.length; i++) {
  69             preText[i] = text.charCodeAt(i);
  70         }
  71
  72         let compText = deflator.deflate(preText);
  73
  74         //Check that the compressed size is expected size
  75         expect(compText.length).to.be.greaterThan((1024 * 10 * 10) * 2);
  76
  77         let inflatedText = _inflator(compText, text.length);
  78
  79         expect(inflatedText).to.array.equal(preText);
  80
  81     });
  82 });