Add release notes.

Bump version.
Obsolete Async method (wasn't properly async anyway).

docs/ReleaseNotes.md

@@ -1,5 +1,9 @@
 # Sylvan.Data.Excel Release Notes
 
+_0.4.16_
+- Adds ExcelFileType class that exposes constants about supported Excel formats: extensions and content types.
+- Add `Obsolete` to `TryOpenWorksheetAsync`, use `TryOpenWorksheet` instead. Information about future Async strategy will be forthcoming.
+
 _0.4.15_
 - Fix a bug that prevented .xlsx reader from working on .NET Framework versions.
 - Fix a bug where FieldRowCount would be incorrect on empty rows.

source/Sylvan.Data.Excel/ExcelDataReader.cs

@@ -8,7 +8,6 @@
 using System.Globalization;
 using System.IO;
 using System.Linq;
-using System.Net;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -175,24 +174,12 @@ public static ExcelDataReader Create(Stream stream, ExcelWorkbookType fileType,
  }
  }
 
- static readonly Dictionary<string, ExcelWorkbookType> FileTypeMap = new(StringComparer.OrdinalIgnoreCase)
- {
- { ".xls", ExcelWorkbookType.Excel },
- { ".xlsx", ExcelWorkbookType.ExcelXml },
- { ".xlsm", ExcelWorkbookType.ExcelXml },
- { ".xlsb", ExcelWorkbookType.ExcelBinary },
- };
-
  /// <summary>
  /// Gets the type of an Excel workbook from the file name.
  /// </summary>
  public static ExcelWorkbookType GetWorkbookType(string filename)
  {
- var ext = Path.GetExtension(filename);
- return
- FileTypeMap.TryGetValue(ext, out var type)
- ? type
- : 0;
+ return ExcelFileType.FindForFilename(filename)?.WorkbookType ?? ExcelWorkbookType.Unknown;
  }
 
  /// <summary>
@@ -202,7 +189,9 @@ public static ExcelWorkbookType GetWorkbookType(string filename)
  /// <returns>True if the sheet was opened, otherwise false.</returns>
  public bool TryOpenWorksheet(string name)
  {
+#pragma warning disable // disable obsolete warning for now.
  return TryOpenWorksheetAsync(name).GetAwaiter().GetResult();
+#pragma warning enable
  }
 
  /// <summary>
@@ -211,6 +200,7 @@ public bool TryOpenWorksheet(string name)
  /// <param name="name">The name of the worksheet to open.</param>
  /// <param name="cancel">A cancellation token for the async operation.</param>
  /// <returns>True if the sheet was opened, otherwise false.</returns>
+ [Obsolete("TryOpenWorksheetAsync will be removed in a future version. Use TryOpenWorksheet instead.")]
  public Task<bool> TryOpenWorksheetAsync(string name, CancellationToken cancel = default)
  {
  var sheetIdx = -1;

source/Sylvan.Data.Excel/Sylvan.Data.Excel.csproj

@@ -3,7 +3,7 @@
  <PropertyGroup>
  <TargetFrameworks>net6.0;netstandard2.1;netstandard2.0</TargetFrameworks>
  <LangVersion>latest</LangVersion>
- <VersionPrefix>0.4.15</VersionPrefix>
+ <VersionPrefix>0.4.16</VersionPrefix>
  <Description>A cross-platform .NET library for reading Excel data files.</Description>
  <PackageTags>excel;xls;xlsx;xlsb;datareader</PackageTags>
  <Nullable>enable</Nullable>