Add try/catch, warning, and tests

Public/Open-ExcelPackage.ps1

@@ -35,7 +35,12 @@
         if ($pkgobj) {
             foreach ($w in $pkgobj.Workbook.Worksheets) {
                 $sb = [scriptblock]::Create(('$this.workbook.Worksheets["{0}"]' -f $w.name))
-                Add-Member -InputObject $pkgobj -MemberType ScriptProperty -Name $w.name -Value $sb
+                try { 
+                    Add-Member -InputObject $pkgobj -MemberType ScriptProperty -Name $w.name -Value $sb -ErrorAction Stop
+                }
+                catch {
+                    Write-Warning "Could not add sheet $($w.name) as 'short cut', you need to access it via `$wb.Worksheets['$($w.name)'] "
+                }
             }
             return $pkgobj
         }

__tests__/Open-ExcelPackage.tests.ps1

@@ -0,0 +1,39 @@
+#Requires -Modules Pester
+
+if (-not (Get-command Import-Excel -ErrorAction SilentlyContinue)) {
+    Import-Module $PSScriptRoot\..\ImportExcel.psd1
+}
+
+<#
+Methods
+-------
+Dispose
+Equals
+GetAsByteArray
+GetHashCode
+GetType
+Load
+Save
+SaveAs
+ToString
+
+Properties
+----------
+
+Compatibility
+Compression
+DoAdjustDrawings
+Encryption
+File
+Package
+Stream
+Workbook
+#>
+
+Describe "Test Open Excel Package" -Tag Open-ExcelPackage { 
+    It "Should handle opening a workbook with Worksheet Names that will cause errors" {
+        $xlFilename = "$PSScriptRoot\UnsupportedWorkSheetNames.xlsx"
+
+        { Open-ExcelPackage -Path $xlFilename -ErrorAction Stop } | Should -Not -Throw
+    }
+}