How to use the oracledb.fetchArraySize function in oracledb

it('13.3.1 should use oracledb.fetchArraySize for fetching', function (done) {
      var defaultFetchArraySize;
      var testFetchArraySize = 9;

      defaultFetchArraySize = oracledb.fetchArraySize;
      oracledb.fetchArraySize = testFetchArraySize;
      var stream = connection.queryStream('SELECT employee_name FROM nodb_stream1 ORDER BY employee_name');

      stream.on('data', function () {
        stream.pause();

        // Using the internal/private caches to validate
        should.equal(stream._resultSet._rowCache.length, testFetchArraySize - (1 + stream._readableState.buffer.length));

        // Using internal close method for Node.js versions < 8
        stream._close(function() {
          oracledb.fetchArraySize = defaultFetchArraySize;
          done();
        });
      });

      stream.on('end', function () {

it('58.1.6 fetchArraySize', function() {
      var t = oracledb.fetchArraySize;
      oracledb.fetchArraySize = t + 1;

      t.should.eql(defaultValues.fetchArraySize);
      (oracledb.fetchArraySize).should.eql(defaultValues.fetchArraySize + 1);
    });

it('58.1.6 fetchArraySize', function() {
      var t = oracledb.fetchArraySize;
      oracledb.fetchArraySize = t + 1;

      t.should.eql(defaultValues.fetchArraySize);
      (oracledb.fetchArraySize).should.eql(defaultValues.fetchArraySize + 1);
    });

var fun_query_out = function(affectFromId, maxArraySizeVal, fetchArraySizeVal, cb) {
      oracledb.fetchArraySize = fetchArraySizeVal;
      connection.execute(
        "BEGIN :output := nodb_ref_fun_pkg.array_out(:c); END;",
        {
          c: { type: oracledb.NUMBER, dir: oracledb.BIND_IN, val: affectFromId },
          output: { type: oracledb.NUMBER, dir: oracledb.BIND_OUT, maxArraySize: maxArraySizeVal }
        },
        function(err, result) {
          should.not.exist(err);
          should.strictEqual(result.outBinds.output.length, tableSize - affectFromId);
          fun_verifyResult_out(result.outBinds.output, affectFromId);
          cb();
        }
      );
    };

describe("151. fetchArraySize4.js", function() {

  var connection = null;
  var default_fetcArraySize = oracledb.fetchArraySize;
  var default_maxRows = oracledb.maxRows;
  var tableName = "nodb_fetchArraySize_151";
  var tableSize = 1000;

  var create_table = "BEGIN \n" +
                     "    DECLARE \n" +
                     "        e_table_missing EXCEPTION; \n" +
                     "        PRAGMA EXCEPTION_INIT(e_table_missing, -00942); \n" +
                     "    BEGIN \n" +
                     "        EXECUTE IMMEDIATE('DROP TABLE " + tableName + " PURGE'); \n" +
                     "    EXCEPTION \n" +
                     "        WHEN e_table_missing \n" +
                     "        THEN NULL; \n" +
                     "    END; \n" +
                     "    EXECUTE IMMEDIATE (' \n" +
                     "        CREATE TABLE " + tableName + " ( \n" +

function(err, result) {
        should.not.exist(err);
        should.strictEqual(oracledb.fetchArraySize, 100);
        should.strictEqual(result.rows[0][0], "fetchArraySize");
        cb();
      }
    );

describe("150. fetchArraySize3.js", function() {

  var connection = null;
  var default_fetcArraySize = oracledb.fetchArraySize;
  var default_maxRows = oracledb.maxRows;
  var tableName = "nodb_fetchArraySize_150";
  var tableSize = 1000;

  var create_table = "BEGIN \n" +
                     "    DECLARE \n" +
                     "        e_table_missing EXCEPTION; \n" +
                     "        PRAGMA EXCEPTION_INIT(e_table_missing, -00942); \n" +
                     "    BEGIN \n" +
                     "        EXECUTE IMMEDIATE('DROP TABLE " + tableName + " PURGE'); \n" +
                     "    EXCEPTION \n" +
                     "        WHEN e_table_missing \n" +
                     "        THEN NULL; \n" +
                     "    END; \n" +
                     "    EXECUTE IMMEDIATE (' \n" +
                     "        CREATE TABLE " + tableName + " ( \n" +

afterEach(function(done) {
      oracledb.fetchArraySize = default_fetcArraySize;
      oracledb.maxRows = default_maxRows;
      done();
    });

after('restore the values', function() {
      oracledb.poolMin          = defaultValues.poolMin;
      oracledb.poolMax          = defaultValues.poolMax;
      oracledb.poolIncrement    = defaultValues.poolIncrement;
      oracledb.poolTimeout      = defaultValues.poolTimeout;
      oracledb.maxRows          = defaultValues.maxRows;
      oracledb.fetchArraySize   = defaultValues.fetchArraySize;
      oracledb.autoCommit       = defaultValues.autoCommit;
      oracledb.connectionClass  = defaultValues.connectionClass;
      oracledb.externalAuth     = defaultValues.externalAuth;
      oracledb.fetchAsString    = defaultValues.fetchAsString;
      oracledb.outFormat        = defaultValues.outFormat;
      oracledb.lobPrefetchSize  = defaultValues.lobPrefetchSize;
      oracledb.queueTimeout     = defaultValues.queueTimeout;
      oracledb.stmtCacheSize    = defaultValues.stmtCacheSize;
      oracledb.poolPingInterval = defaultValues.poolPingInterval;
      oracledb.fetchAsBuffer    = defaultValues.fetchAsBuffer;
      oracledb.edition          = defaultValues.edition;
      oracledb.events           = defaultValues.events;
    });

describe("148. fetchArraySize1.js", function() {

  var connection = null;
  var defaultVal = oracledb.fetchArraySize;

  before(function(done) {
    oracledb.getConnection(dbConfig, function(err, conn) {
      should.strictEqual(defaultVal, 100);
      should.not.exist(err);
      connection = conn;
      done();
    });
  });

  after(function(done) {
    connection.close(function(err) {
      should.not.exist(err);
      done();
    });
  });