xSQLServerCommon.Tests: Example test might need more logic to use example file configuration data hash table

[johlju]

Details of the scenario you try and problem that is occurring:
When creating an example file with more logic, for example evaluating variables in the ConfigurationData hash table. Then the test will ignore those.

The test uses a default mock ConfigurationData block.
https://github.com/PowerShell/xSQLServer/blob/dev/Tests/xSQLServerCommon.Tests.ps1#L51

Instead it should use the ConfigurationData hash table if it exists in the example file. The hash table must have a predetermined variable name so we know what to look for.

One example of this is the example for the new resource xSQLServerAlwaysOnAvailabilityGroup.
https://github.com/PowerShell/xSQLServer/pull/338/files#diff-4431c91d275e14a60f0e1ce5e29ae081

The DSC configuration that is using the resource (as detailed as possible):
n/a

Version of the Operating System, SQL Server and PowerShell the DSC Target Node is running:
n/a

Version of the DSC module you're using, or 'dev' if you're using current dev branch:
Dev

[johlju]

I suggest the predetermined variable name should be $ConfigurationData. In the test there is a $mockConfigurationData that will be used by default. But if $ConfigurationData is found when dot sourcing the example into the common test, then $ConfigurationData will be used instead of $mockConfigurationData.

[johlju]

How the layout of the examples should look like needs to be added to the specific contribution guidelines as well.

[johlju]

Putting this on hold since this is being worked on as a common test over at Powershell\DscResource.Tests

[johlju]

Closing this one as we should use the common test for this. In progress in issue #669.