Powershell script Missingtypename - json

Question

I am trying to make some API calls through powershell using this documentation
https://octopus.com/blog/manually-push-build-information-to-octopus
$Headers = #{"X-Octopus-ApiKey"=$MYKEY"}
$jsonBody = #{
PackageId = "Test"
Version = "1.1.1"
OctopusBuildInformation =
#{
BuildEnvironment = "Jenkins"
BuildNumber = "1"
BuildURL = "myURL"
VcsCommitNumber = "250"
VcsType = "Git"
Commits = [{Id = "250" LinkUrl = "gitUrl" Comment = "someComment"}]
VcsRoot = "gitUrl"
}
} | ConvertTo-Json -Depth 5
Invoke-RestMethod -Method Post -Uri "http://alfadeployment/api/build-information" -Headers $Headers -Body $jsonBody
However, since I added the commits array, I am getting the following error:
Missing type name after '['.
+ CategoryInfo : ParserError: (:) [], ParseException
+ FullyQualifiedErrorId : MissingTypename

Answer 1

PowerShell arrays aren't enclosed in [...] - the latter is used for type literals, i.e. to refer to .NET types - hence the error message.
You may - but don't have to - enclose PowerShell arrays in #(...), the array-subexpression operator; using ,, the array constructor operator is enough, though #(...) can be helpful for visual clarity, and to create an empty (#()) or single-element arrays (#('foo')), which is perhaps clearer than the unary use of , (, 'foo')).
Additionally, the array element in your case must be a hashtable too (#{ ... }, not { ... }, the latter is a script block), and, given that the property definitions are on the same line, they must be ;-separated.
To put it all together:
Commits = #(
#{ Id = "250"; LinkUrl = "gitUrl"; Comment = "someComment" }
)