"Credentials are required" if "optional" is removed from parameter

Preflight Checklist

• I have installed the latest version of Power Query SDK.
• I have checked existing resources, including the common issues and the release notes.
• I have searched for similar issues.

Power Query SDK

0.4.0

Regression From

No response

Platform

Windows

Architecture

x64

OS Version

Windows 11

VSCode version

1.91.1

PQSdkTool Path

No response

Bug Description

This isn't an issue with the tool, but regarding modifying the sample code. If I remove "optional" from the DefaultConnector.Contents parameter, I get "Credentials are required to connect to the DefaultConnector source". I have credentials set and it works fine until I make this change.
I'm thinking having this work in the sample is important because I understand optional parameters are not displayed in the Power BI connector configuration GUI and are just assigned null.

SETTING CREDENTIALS:
[3:11:26 PM] [Info] CreateAuthState {
"Details": {
"Kind": "DefaultConnector",
"Path": "DefaultConnector",
"NormalizedPath": "DefaultConnector",
"IsDefaultForKind": false
},
"Message": "Successfully set credential",
"Status": "Success"
}
...
RUN WITHOUT CHANGES
[3:11:39 PM] [Info] RunTestBattery result [
{
"ActivityId": "770e4cd9-88be-45ff-8fc2-1c0732284696",
"DataSourceAnalysis": [
{
"Kind": "DataSource",
"FunctionName": "DefaultConnector.Contents",
"DataSource": {
"Kind": "DefaultConnector",
"NormalizedPath": "DefaultConnector",
"Path": "DefaultConnector"
}
}
],
"Details": "// Use this file to write queries to test your data connector\r\nlet\r\n result = DefaultConnector.Contents()\r\nin\r\n result\r\n",
"EndTime": "2024-07-14T19:11:39.2428572+00:00",
"Method": "PQTest.RunTest",
"Name": "DefaultConnector.query.pq",
"StartTime": "2024-07-14T19:11:38.3535741+00:00",
"Output": [
{
"Value": "Hello from DefaultConnector: (no message)"
}
],
"DiagnosticEvents": {},
"RowCount": 1,
"Status": "Passed",
"Type": "PQTest.Expression"
}
]
...
RUN WITH PASSING IN A STRING
[3:11:59 PM] [Info] RunTestBattery result [
{
"ActivityId": "98016a87-8190-45e2-8d53-fc39e529f32e",
"DataSourceAnalysis": [
{
"Kind": "DataSource",
"FunctionName": "DefaultConnector.Contents",
"DataSource": {
"Kind": "DefaultConnector",
"NormalizedPath": "DefaultConnector",
"Path": "DefaultConnector"
}
}
],
"Details": "// Use this file to write queries to test your data connector\r\nlet\r\n result = DefaultConnector.Contents("xyzzy")\r\nin\r\n result\r\n",
"EndTime": "2024-07-14T19:11:59.7930444+00:00",
"Method": "PQTest.RunTest",
"Name": "DefaultConnector.query.pq",
"StartTime": "2024-07-14T19:11:58.8065551+00:00",
"Output": [
{
"Value": "Hello from DefaultConnector: xyzzy"
}
],
"DiagnosticEvents": {},
"RowCount": 1,
"Status": "Passed",
"Type": "PQTest.Expression"
}
]
...
RUN HAVING REMOVED "OPTIONAL" FROM PARAMETER
[3:12:30 PM] [Info] RunTestBattery result [
{
"ActivityId": "b1e1417d-c9ba-4e4a-b826-c9ec24a2616d",
"DataSourceAnalysis": [
{
"Kind": "DataSource",
"FunctionName": "DefaultConnector.Contents",
"DataSource": {
"Kind": "DefaultConnector",
"NormalizedPath": "{"message":"xyzzy"}",
"Path": "{"message":"xyzzy"}"
}
}
],
"Details": "Credentials are required to connect to the DefaultConnector source. (Source at {"message":"xyzzy"}.)",
"EndTime": "2024-07-14T19:12:30.3237535+00:00",
"Method": "PQTest.RunTest",
"Name": "DefaultConnector.query.pq",
"StartTime": "2024-07-14T19:12:29.3827084+00:00",
"DiagnosticEvents": {},
"RowCount": 0,
"Status": "Failed",
"Type": "PQTest.Expression",
"Error": {
"Message": "Credentials are required to connect to the DefaultConnector source. (Source at {"message":"xyzzy"}.)",
"Details": {
"Microsoft.Data.Mashup.CredentialError.Reason": "CredentialMissing",
"Microsoft.Data.Mashup.CredentialError.DataSourceKind": "DefaultConnector",
"Microsoft.Data.Mashup.CredentialError.DataSourcePath": "{"message":"xyzzy"}",
"Microsoft.Data.Mashup.MashupSecurityException.Reason": "CredentialMissing",
"Microsoft.Data.Mashup.MashupSecurityException.DataSources": "[{"kind":"DefaultConnector","path":"{\"message\":\"xyzzy\"}"}]"
}
}
}
]

Steps to Reproduce

1. Launch SDK extension.
2. Modify DefaultConnector.pq by removing "optional" from the parameter in DefaultConnector.Contents.
3. Pass a string in to the call to DefaultConnector.Contents in DefaultConnector.query.pq.
4. Set Credentials.
5. Evaluate DefaultConnector.query.pq

Actual Experience

Results pane shows output with message.

Expected Experience

Error "Credentials are required to connect to the DefaultConnector source."

Additional Context

No response

Start with the sample files DefaultConnector.pq and DefaultConnector.query.pq, then reproduce the listed steps in the Power Query SDK using the test battery. Compare behavior with the parameter marked optional and with it removed; done means the credential handling and result match the intended expected experience documented in the issue.