Single value array being converted to String - Powershell - powershell

Question

I am converting this to JSON and sending in a POST request but the value of ContextTypes keeps getting converted to string.
$postParams = #{
instance=[PSCustomObject]#{
instanceId= $instanceId;
className="Permission";
schemaName="RBAC";
properties= #{
Name= $Name;
Description= $Description;
ServiceGPRId= 1;
CategoryId= 1;
ContextTypes=#('Object')
};
}
} | ConvertTo-Json
returns:
{
"instance": {
"instanceId": null,
"className": "Permission",
"schemaName": "RBAC",
"properties": {
"CategoryId": 1,
"ServiceGPRId": 1,
"Description": null,
"Name": null,
"ContextTypes": "Object"
}
}}
I have seen other answers and have tried (#(...)) as well, it doesn't work. For some reason, if I define the same name-value pair outside of the properties object, it works fine and returns:
{
"instance": {
"instanceId": null,
"className": "Permission",
"schemaName": "RBAC",
"ContextTypes": [
"Object"
],
"properties": {
"CategoryId": 1,
"ServiceGPRId": 1,
"Description": null,
"Name": null
}
}
}
I also tried converting it to Json using the -InputObject method, but that gives same results.
How do I make sure ContextTypes remains an array?

Answer 1

You need to add -Depth 3 to your ConvertTo-Json call to ensure that your object graph is serialized to its full depth:
#{
instance= [PSCustomObject] #{
instanceId= $instanceId
className="Permission"
schemaName="RBAC"
properties= [PSCustomObject] #{
Name= $Name
Description= $Description
ServiceGPRId = 1
CategoryId = 1
ContextTypes = #('Object')
}
}
} | ConvertTo-Json -Depth 3
Unfortunately, -Depth defaults to 2, which explains your - subtle - symptom: essentially, your array was serialized as its string-expanded value, which yielded just its (only) element (e.g., "$(#('foo'))" yields 'foo').
For background information, see:
this post.
this GitHub issue.