Add SparseVerb --add

[wilbaker]

Resolves #76

• Added SparseVerb to Scalar
• SparseVerb supports adding folders to the sparse-checkout with --add and --add-stdin
• SparseVerb add prefetches the requested folders before calling git sparse-checkout add with the specified folders

TODO

• Wire-up a call to git sparse-checkout add
• Add support for providing folders over stdin

[wilbaker]

@derrickstolee there is still some work to do here, but I'm putting my current changes up in a PR in case you want to pick this work up before I get back to it.

Sample output with the current changes:

~/ScalarTest/src>git status
On branch master
Your branch is up to date with 'origin/master'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   License.md

no changes added to commit (use "git add" and/or "git commit -a")
~/ScalarTest/src>
~/ScalarTest/src>
~/ScalarTest/src>~/Repos/GSD/Publish/scalar sparse --add GVFS/GVFS
Running git status...Failed

On branch master
Your branch is up to date with 'origin/master'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   License.md

no changes added to commit (use "git add" and/or "git commit -a")

git status reported that you have dirty files
Either commit your changes or reset and clean
sparse was aborted
~/ScalarTest/src>git checkout -- License.md 
~/ScalarTest/src>~/Repos/GSD/Publish/scalar sparse --add GVFS/GVFS
Running git status...Succeeded
All requested files are already available. Nothing new to prefetch.
~/ScalarTest/src>~/Repos/GSD/Publish/scalar sparse --add Scripts/
Running git status...Succeeded
Authenticating...Succeeded
Querying remote for config...Succeeded
Configured cache server: None (https://gvfs.visualstudio.com/ci/_git/ForTests)
Fetching blobs from origin (no cache server)...Succeeded

Stats:
  Matched blobs:    13
  Already cached:   13
  Downloaded:       0
~/ScalarTest/src>

[derrickstolee]

I like the progress! Just a few ideas for the future direction.

[derrickstolee]

@wilbaker now that #54 is merged, you can rebase this topic onto master and start using the git sparse-checkout add command.

[wilbaker]

@derrickstolee thanks for feedback! I am going to push a few more commits while this is still WIP, and then clean up the commit history before removing the WIP.

[wilbaker]

Sample run with current changes:

~>cd ScalarTests/src
~/ScalarTests/src>git sparse-checkout list
/*
!/*/*
~/ScalarTests/src>~/Repos/GSD/Publish/scalar sparse --add "GVFS/GVFS.GVFlt;GVFS/GVFS"
Authenticating...Succeeded
Querying remote for config...Succeeded
Configured cache server: None (https://gvfs.visualstudio.com/ci/_git/ForTests)
Fetching blobs from origin (no cache server)...Succeeded

Stats:
  Matched blobs:    67
  Already cached:   67
  Downloaded:       0
~/ScalarTests/src>git sparse-checkout list
/*
!/*/*
/GVFS/*
!/GVFS/*/*
/GVFS/GVFS/*
/GVFS/GVFS.GVFlt/*
~/ScalarTests/src>~/Repos/GSD/Publish/scalar sparse --add-stdin
Scripts
GitHooksLoader
Authenticating...Succeeded
Querying remote for config...Succeeded
Configured cache server: None (https://gvfs.visualstudio.com/ci/_git/ForTests)
Fetching blobs from origin (no cache server)...Succeeded

Stats:
  Matched blobs:    21
  Already cached:   21
  Downloaded:       0
~/ScalarTests/src>git sparse-checkout list
/*
!/*/*
/GVFS/*
!/GVFS/*/*
/GVFS/GVFS/*
/GVFS/GVFS.GVFlt/*
/GitHooksLoader/*
/Scripts/*
~/ScalarTests/src>

[wilbaker]

@derrickstolee the functional tests are still running but this PR is ready for another look 😄

I squashed my changes down to a single commit.

[derrickstolee]

@wilbaker This looks good to me. It doesn't seem to collide with #84 at all, and would unblock @jeschu1 to build more tests as part of #78.