Fix for issue 876 on the maintenance branch (#879)

* Fixes issue 876 on the maintenance branch

* Moved check for sheet name length after the GetSheetInfos call

Signed-off-by: Michele Bastione <[email protected]>

---------

Signed-off-by: Michele Bastione <[email protected]>

Author: michelebastione

src/MiniExcel/OpenXml/ExcelOpenXmlSheetWriter.DefaultOpenXml.cs

@@ -28,6 +28,9 @@ private IEnumerable<Tuple<SheetDto, object>> GetSheets()
                 {
                     sheetId++;
                     var sheetInfos = GetSheetInfos(sheet.Key);
+                    if (sheetInfos.ExcelSheetName.Length > 31)
+                        throw new ArgumentException("Sheet names must be less than 31 characters");
+
                     yield return Tuple.Create(sheetInfos.ToDto(sheetId), sheet.Value);
                 }
 
@@ -424,3 +427,4 @@ private string GetCellXfId(string styleIndex)
         }
     }
 }
+

tests/MiniExcelTests/MiniExcelIssueTests.cs

@@ -4699,4 +4699,24 @@ public void TestIssue869(string fileName, DateOnlyConversionMode mode, bool thro
             }
         }
     }
+    
+    [Fact]
+    public void TestIssue876()
+    {
+        var someTable = new[] 
+        {
+            new { Name = "Jack", Age = 25 }, 
+        };
+
+        var sheets = new Dictionary<string, object>
+        {
+            ["SomeVeryLongNameWithMoreThan31Characters"] = someTable
+        };
+
+        Assert.Throws<ArgumentException>(() =>
+        {
+            using var outputPath = AutoDeletingPath.Create();
+            MiniExcel.SaveAs(outputPath.ToString(), sheets);
+        });
+    }
 }