in src/infertypes.ts [262:278]
var addValue = function(v) {
if (v === undefined) {
optional = true;
return;
}
var is_special_num = is_special_numeric(v);
setVals.push(v);
// Detect non-numeric column
if ((typeof v != "number" && !is_special_num && isNaN(v)) ||
v === true || v === false) {
numeric = false;
can_be_timestamp = false;
}
if (!Number.isSafeInteger(v) || v < 0) {
can_be_timestamp = false;
}
}