Branches

The following code creates an item and specifies the branch id. It does not create a real branch.

public void HowToSetBranchId()
{
  var branchId = Sitecore.Data.ID.NewID;

  using (var db = new Sitecore.FakeDb.Db
    {
      new Sitecore.FakeDb.DbItem("home") { BranchId = branchId }
    })
  {
    Sitecore.Data.Items.Item item = db.GetItem("/sitecore/content/home");

    // assert
    Xunit.Assert.Equal(branchId, item.BranchId);
  }
}

The following code creates a fake branch, then creates a an item based on the fake branch.

public void HowToCreateBranch()
{
  var branchId = Sitecore.Data.ID.NewID;
  var parentId = Sitecore.Data.ID.NewID;

  using (var db = new Sitecore.FakeDb.Db
    {
      new Sitecore.FakeDb.DbItem(
        "Branch Template",
        branchId,
        Sitecore.TemplateIDs.BranchTemplate),

      new Sitecore.FakeDb.DbItem("Parent", parentId)
    })
  {
    var parent = db.GetItem(parentId);
    var child = parent.Add("Child Based on Branch", new Sitecore.Data.BranchId(branchId));

    // assert
    Xunit.Assert.Equal(branchId, child.BranchId);
  }
}