xVhdFileDirectory Unit Tests

[dacarab]

Pull Request (PR) description

PR that adds some basic initial unit tests for the xVhdFileDirectory resource. There is a bug that I'd like to fix around copying to VHDs with multiple partitions - before I look into that, I'd like to put some unit tests in place.

I have not covered off tests for any of the private functions within the resource as of yet, as I may propose to change a couple.

This Pull Request (PR) fixes the following issues

• Potentially contributes to #119

Task list

• [x] Added an entry under the Unreleased section of the change log in the CHANGELOG.md. Entry should say what was changed, and how that affects users (if applicable).
• [ ] Resource documentation added/updated in README.md.
• [ ] Resource parameter descriptions added/updated in README.md, schema.mof and comment-based help.
• [ ] Comment-based help added/updated.
• [ ] Localization strings added/updated in all localization files as appropriate.
• [ ] Examples appropriately added/updated.
• [x] Unit tests added/updated. See DSC Resource Testing Guidelines.
• [ ] Integration tests added/updated (where possible). See DSC Resource Testing Guidelines.
• [x] New/changed code adheres to DSC Resource Style Guidelines and Best Practices.

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This change is 

[codecov[bot]]

Codecov Report

Merging #180 into dev will not change coverage. The diff coverage is n/a.

@@         Coverage Diff         @@
##            dev   #180   +/-   ##
===================================
  Coverage    83%    83%           
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  Files        11     11           
  Lines      1401   1401           
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  Hits       1166   1166           
  Misses      235    235

[johlju]

@mcollera or @aromano2 you are listed as maintainers for this module. Do you have time to review this one?

[aromano2]

@johlju yes looking at it now, thanks!