Certain characters generate errors when used in JSON global variables in config files, such as the .
below.
{
"globals": {
"jest.": true
}
}
Leading spaces and numbers are also disallowed:
{
"globals": {
"123ABC": true
}
}
As are certain unicode characters:
{
"globals": {
"\u2604": true
}
}
To fix this error, rename variables to exclude disallowed characters and leading numbers or spaces.