Adding a substring in powershell - json

Question

I import a csv file in powershell with this code:
import-csv "input.csv" | ConvertTo-Json | Add-Content -Path "output.json"
My output:
{
"users": [
{
"firstName": "name1",
"lastName": "lastname1",
}
{
"firstName": "name2",
"lastName": "lastname2",
}
}
The csv file look like this:
firstname,lastname
name1,lastname1
name2,lastname2
But I need to ad a extra column called "roles" with sub content (I dont know what its called). It should be after lastname, but still part of the users object and in every entry.
Need this output
{
"users": [
{
"firstName": "name1",
"lastName": "lastname1"
"roles:" ["role1", "role2"]
}
{
"firstName": "name2",
"lastName": "lastname2",
"roles:" ["role1", "role2"]
}
}
New output
"Roles": {
"value": [
"Role1",
"Role2"
],
"Count": 2
}

Answer 1

Add-Member is a somewhat slow method but viable...
$json = ConvertFrom-Json #'
{
"users": [{
"firstName": "name1",
"lastName": "lastname1"
},
{
"firstName": "name2",
"lastName": "lastname2"
}
]
}
'#
$json.users | Add-Member -MemberType NoteProperty -Name Roles -Value 'empty'
$json | ConvertTo-Json
Output
{
"users": [{
"firstName": "name1",
"lastName": "lastname1",
"Roles": "empty"
},
{
"firstName": "name2",
"lastName": "lastname2",
"Roles": "empty"
}
]
}
But we are leaning towards you are looking for something like this instead...
$json | Add-Member -MemberType NoteProperty -Name roles -Value #('role1','role2')
Output
{
"users": [
{
"firstName": "name1",
"lastName": "lastname1"
},
{
"firstName": "name2",
"lastName": "lastname2"
}
],
"roles": [
"role1",
"role2"
]
}

Answer 2

#'
firstname,lastname
name1,lastname1
name2,lastname2
'# |
ConvertFrom-Csv |
Select-Object -Property *,#{Name = 'Roles';Expression= {#('Role1','Role2')}} |
ConvertTo-Json
... produces this output:
[
{
"firstname": "name1",
"lastname": "lastname1",
"Roles": [
"Role1",
"Role2"
]
},
{
"firstname": "name2",
"lastname": "lastname2",
"Roles": [
"Role1",
"Role2"
]
}
]