Elasticsearch failed to execute script - elasticsearch

Question

Elasticsearch version 7.7.0
This is the part of the mapping:
const PROFILE_MAPPING = {
mappings: {
properties: {
_userLocation: {
type: "geo_point"
},
_ignoredBy: {
type: "nested"
}
}
}
};
_ignoredBy data example:
[{
"until" : "2020-12-03T16:20:43.176Z",
"user" : <USER_ID>
}]
and this is the script I'm running to update it:
await client.update({
index,
id: target,
refresh: "wait_for",
body: {
script: {
source:
"ctx._source._ignoredBy.removeIf(item -> item.user ==
params.by.user);ctx._source._ignoredBy.add(params.by)",
params: {
by: {
user: initiator,
until: addSeconds(new Date(), ignoreInterval)
}
}
}
}
});
and this is the error I'm getting:
{
"error": {
"root_cause": [
{
"type": "illegal_argument_exception",
"reason": "failed to execute script"
}
],
"type": "illegal_argument_exception",
"reason": "failed to execute script",
"caused_by": {
"type": "script_exception",
"reason": "runtime error",
"script_stack": ["item -> item.user == params.by.user);", "^---- HERE"],
"script": "ctx._source._ignoredBy.removeIf(item -> item.user == params.by.user);ctx._source._ignoredBy.add(params.by)",
"lang": "painless",
"position": { "offset": 32, "start": 32, "end": 69 },
"caused_by": { "type": "null_pointer_exception", "reason": null }
}
},
"status": 400
}
The weird thing is that this works 99% of the time but errors are appearing on logs and can't figure out what's the reason. The params passed in are 100% there as they appear on logs.

Answer 1

Such null pointers are hard to wrap one's head around but my hunch is that there's something off with ctx._source._ignoredBy itself.
In that spirit, I'd suggest to add one more check before I'm calling .removeIf on it -- perhaps initialize it in case it's null:
{
"script": {
"source": "if (ctx._source._ignoredBy == null) {ctx._source._ignoredBy = []; } ctx._source._ignoredBy.removeIf(item -> item.user == params.by.user); ctx._source._ignoredBy.add(params.by)",
"params": {
...
}
}
}