dynoexpr doesn't support list_append

[dawidk92]

dynoexpr doesn't support list_append

[dawidk92]

It works as expected right now. Thank you @ruicsh ❤️

[ruicsh]

hi @dawidk92 thanks for your missing feature report. It's implemented on 2.14.0. I don't have access to a DynamoDB right now, if you could test this out. I think you always need 2 args to list_append, one of them being the key

const params = dynoexpr({
  Update: { numbersArray: 'list_append([1, 2], numbersArray)' },
});

/*
{
  UpdateExpression: 'SET #neb9c = list_append(:v4136, #neb9c)',
  ExpressionAttributeNames: { '#neb9c': 'numbersArray' },
  ExpressionAttributeValues: { ':v4136': '[1, 2]' },
}
*/

[dawidk92]

Hi @ruicsh it's almost fine but it has a minor bug.

ExpressionAttributeValues returns value as a string:
{ ':v4136': '[1, 2]' }

and it should be returned as an array:
{ ':v4136': [1, 2] }

DynamoDB throws this error:
ValidationException: Invalid UpdateExpression: Incorrect operand type for operator or function; operator or function: list_append, operand type: S

[ruicsh]

hey, fixed it on v2.14.1:

const params = dynoexpr({
  Update: { numbersArray: 'list_append([1, 2], numbersArray)' },
});

/*
{
  UpdateExpression: 'SET #neb9c = list_append(:veb45, #neb9c)',
  ExpressionAttributeNames: { '#neb9c': 'numbersArray' },
  ExpressionAttributeValues: { ':veb45': [1, 2] },
}
*/

[dawidk92]

@ruicsh it works fine with an array of numbers but it doesn't work with an array of strings:

const params = dynoexpr({
  Update: { stringsArray: 'list_append(["a", "b"], stringsArray)' },
});

/*
{
  UpdateExpression: 'SET #neb9c = list_append(:veb45, #neb9c)',
  ExpressionAttributeNames: { '#neb9c': 'stringsArray' },
  ExpressionAttributeValues: { ':veb45': [null] },
}
*/

DynamoDB throws an error:
Error: Special numeric value NaN is not allowed

I created a temporary hack in my app where I put the output of the previously (v2.14.0) created value from ExpressionAttributeValues to JSON.parse() and it works just fine. Maybe that would be a solution to that problem.

[ruicsh]

yea, fixed it on v2.14.2