ui/src/base/resizable_array_buffer_unittest.ts

// Copyright (C) 2018 The Android Open Source Project
//
// 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.

import {pseudoRand} from './rand';
import {ResizableArrayBuffer} from './resizable_array_buffer';

test('ResizableArrayBuffer.simple', () => {
  const buf = new ResizableArrayBuffer();
  buf.append([1, 2]);
  expect(buf.get()).toEqual(new Uint8Array([1, 2]));

  buf.append([3]);
  expect(buf.get()).toEqual(new Uint8Array([1, 2, 3]));

  buf.clear();
  expect(buf.get().length).toEqual(0);
  expect(buf.get()).toEqual(new Uint8Array([]));
});

test('ResizableArrayBuffer.merge', () => {
  const buf = new ResizableArrayBuffer();

  // Append to the buffer in batches of variables sizes, filling with a
  // pseudo-random sequence.
  const randState = {seed: 1};
  const randU8 = () => (pseudoRand(randState) * 256) & 0xff;
  const BATCH_SIZES = [11, 129, 1023, 1024 * 7];
  const TOTAL_SIZE = BATCH_SIZES.reduce((a, s) => a + s, 0);
  const expected = new Uint8Array(TOTAL_SIZE);
  let e = 0;
  for (const batchSize of BATCH_SIZES) {
    const batch = new Uint8Array(batchSize);
    for (let i = 0; i < batch.length; i++) {
      const num = randU8();
      batch[i] = num;
      expected[e++] = num;
    }
    buf.append(batch);
  }

  // Now reset the seed and check that the random sequence of the merged array
  // matches.
  const merged = buf.get();
  expect(merged.length).toEqual(expected.length);
  expect(merged).toEqual(expected);
});