Explain the intention of the test-binary-notnull-nulls test

I am trying to fix the failing test cases, but I cannot wrap my head around some, e.g. test-binary-notnull-nulls.

First,

fields[0].flags & FieldFlags.NOT_NULL

From: https://github.com/sidorares/node-mysql2/blob/e83efa4c561eb28f7de6aa9349764a265c1f1148/test/integration/connection/test-binary-notnull-nulls.js#L46

FieldFlags.NOT_NULL is 1 (a harcoded value), this will always be true. If you want to check that column is no nullable, then why not use IS?, e.g.

conn.execute("SELECT IS_NULLABLE FROM INFORMATION_SCHEMA.COLUMNS WHERE `table_schema`=DATABASE() AND `table_name` = 'tmp_account' AND `column_name`='username'", function (error, informationSchemaRows) {
  var usernameIsNullable = informationSchemaRows[0].IS_NULLABLE === 'YES';

Second rows[0][fields[0].name] === null (https://github.com/sidorares/node-mysql2/blob/e83efa4c561eb28f7de6aa9349764a265c1f1148/test/integration/connection/test-binary-notnull-nulls.js#L47).

Username is not null. Either the setup query is wrong or the assertion query is wrong. This could also have to do with the sql_mode=only_full_group_by introduced in 5.7. Though, if the previous behaviour relied on ANY_VALUE(), this would have been failing for a long time.