Add Sheet tests

Tests for `Sheets.get` and `Sheets.getSheets`.

tests/FsSpreadsheet.ExcelIO.Tests/FsSpreadsheet.ExcelIO.Tests.fsproj

@@ -9,6 +9,7 @@
   <ItemGroup>
     <Compile Include="Spreadsheet.fs" />
     <Compile Include="Workbook.fs" />
+    <Compile Include="Sheet.fs" />
     <Compile Include="Main.fs" />
   </ItemGroup>
 

tests/FsSpreadsheet.ExcelIO.Tests/Sheet.fs

@@ -0,0 +1,29 @@
+module Sheet
+
+open Expecto
+open FsSpreadsheet.ExcelIO
+open DocumentFormat.OpenXml
+
+let testFilePath = System.IO.Path.Combine(__SOURCE_DIRECTORY__, "data", "testUnit.xlsx")
+// *fox = from OpenXml, to distinguish between objects from FsSpreadsheet.ExcelIO
+let ssdFox = Packaging.SpreadsheetDocument.Open(testFilePath, false)
+let wbpFox = ssdFox.WorkbookPart
+let wbFox = wbpFox.Workbook
+let shtsFox = wbFox.Sheets
+let shtssFox = shtsFox.Descendants<Spreadsheet.Sheet>() |> Array.ofSeq      // array is needed since seqs cannot be compared
+
+
+[<Tests>]
+let sheetsTests =
+    testList "Sheets" [
+        testList "get" [
+            testCase "is equal to shtsFox" <| fun _ ->
+                let shts = Sheet.Sheets.get wbFox
+                Expect.equal shts shtsFox "Differs"
+        ]
+        testList "getSheets" [
+            testCase "is equal to shtssFox" <| fun _ ->
+                let shtss = Sheet.Sheets.getSheets shtsFox |> Array.ofSeq   // array is needed since seqs cannot be compared
+                Expect.equal shtss shtssFox "Differs"
+        ]
+    ]