Using Visual Studio to develop and test Data Connector

[john_dawson]

This is a brilliant facility, at least in comparison to the native support for development of M in Power BI, which is little better than Notepad, which is pretty brutal

There is a basic testing facility which part of the VS setup, into which you typically hard-code some values to test your connector

The connector is called (say) MyConnectorName.pq, and the test harness is called MyConnectorName.query.pq - and I guess you could have more than one of those

I think I found a bug: if I change something in the test harness, it (somethimes?) isn't propagated; I only tracked this down by looking at a Fiddler trace

I've tried dropping re-building, re-starting, re-adding the MyConnectorName.query.pq file, to no avail

Anyone else found this? Is there a good workaround?

[v-jiascu-msft]

Hi @john_dawson,

Can you share some details? What did you change? 

Best Regards,

Dale

[john_dawson]

Hi Dale, our Data Connector (DC) takes a number of parameters, and the query.pq file calls the DC, with hard-coded values for the parameters

It was working fine for a while, but then I added another parameter to the DC, and I get an error message saying the parameter value is blank; at first I thought I'd made an error, but I checked the DC with the actual Power BI application and it worked fine, even though the query.pq still failed

I'm sorry, I'm not a liberty to share screenshots, as this is customer sensitive data

A further puzzle if if I actually delete the query.pq file completely from the solution (so not visible in solution explorer) and run the test, instred of saying it can't run the test (which I'd expect) it still comes up with the same error

It's as if the test is running an "invisible" query.pq file

I think I'll drop and re-created the solution completely; perhaps it's got messed up somehow - I'll let you know here

[john_dawson · Accepted solution]

I did drop and re-create my solution, which has indeed resolved the issue - apparently; I guess that will have to do as no way of finding out what was really going on. Thanks for reply