test/dataview/dataview_read_write.js

/* eslint-disable no-eval */
'use strict';

const assert = require('assert');

module.exports = require('../common').runTest(test);

function test (binding) {
  function expected (type, value) {
    return eval(`(new ${type}Array([${value}]))[0]`);
  }

  function nativeReadDataView (dataview, type, offset, value) {
    return eval(`binding.dataview_read_write.get${type}(dataview, offset)`);
  }

  function nativeWriteDataView (dataview, type, offset, value) {
    eval(`binding.dataview_read_write.set${type}(dataview, offset, value)`);
  }

  // eslint-disable-next-line no-unused-vars
  function isLittleEndian () {
    const buffer = new ArrayBuffer(2);
    new DataView(buffer).setInt16(0, 256, true /* littleEndian */);
    return new Int16Array(buffer)[0] === 256;
  }

  function jsReadDataView (dataview, type, offset, value) {
    return eval(`dataview.get${type}(offset, isLittleEndian())`);
  }

  function jsWriteDataView (dataview, type, offset, value) {
    eval(`dataview.set${type}(offset, value, isLittleEndian())`);
  }

  function testReadData (dataview, type, offset, value) {
    jsWriteDataView(dataview, type, offset, 0);
    assert.strictEqual(jsReadDataView(dataview, type, offset), 0);

    jsWriteDataView(dataview, type, offset, value);
    assert.strictEqual(
      nativeReadDataView(dataview, type, offset), expected(type, value));
  }

  function testWriteData (dataview, type, offset, value) {
    jsWriteDataView(dataview, type, offset, 0);
    assert.strictEqual(jsReadDataView(dataview, type, offset), 0);

    nativeWriteDataView(dataview, type, offset, value);
    assert.strictEqual(
      jsReadDataView(dataview, type, offset), expected(type, value));
  }

  function testInvalidOffset (dataview, type, offset, value) {
    assert.throws(() => {
      nativeReadDataView(dataview, type, offset);
    }, RangeError);

    assert.throws(() => {
      nativeWriteDataView(dataview, type, offset, value);
    }, RangeError);
  }

  const dataview = new DataView(new ArrayBuffer(22));

  testReadData(dataview, 'Float32', 0, 10.2);
  testReadData(dataview, 'Float64', 4, 20.3);
  testReadData(dataview, 'Int8', 5, 120);
  testReadData(dataview, 'Int16', 7, 15000);
  testReadData(dataview, 'Int32', 11, 200000);
  testReadData(dataview, 'Uint8', 12, 128);
  testReadData(dataview, 'Uint16', 14, 32768);
  testReadData(dataview, 'Uint32', 18, 1000000);

  testWriteData(dataview, 'Float32', 0, 10.2);
  testWriteData(dataview, 'Float64', 4, 20.3);
  testWriteData(dataview, 'Int8', 5, 120);
  testWriteData(dataview, 'Int16', 7, 15000);
  testWriteData(dataview, 'Int32', 11, 200000);
  testWriteData(dataview, 'Uint8', 12, 128);
  testWriteData(dataview, 'Uint16', 14, 32768);
  testWriteData(dataview, 'Uint32', 18, 1000000);

  testInvalidOffset(dataview, 'Float32', 22, 10.2);
  testInvalidOffset(dataview, 'Float64', 22, 20.3);
  testInvalidOffset(dataview, 'Int8', 22, 120);
  testInvalidOffset(dataview, 'Int16', 22, 15000);
  testInvalidOffset(dataview, 'Int32', 22, 200000);
  testInvalidOffset(dataview, 'Uint8', 22, 128);
  testInvalidOffset(dataview, 'Uint16', 22, 32768);
  testInvalidOffset(dataview, 'Uint32', 22, 1000000);
}