Fix dimension writing in FastMode (#659)

* Add tests for fast mode

* Fix dimension writing in FastMode

src/MiniExcel/OpenXml/Constants/WorksheetXml.cs

@@ -8,10 +8,9 @@ namespace MiniExcelLibs.OpenXml.Constants
         internal const string StartWorksheetWithRelationship = @"<?xml version=""1.0"" encoding=""utf-8""?><x:worksheet xmlns:r=""http://schemas.openxmlformats.org/officeDocument/2006/relationships"" xmlns:x=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"" >";
         internal const string EndWorksheet = "</x:worksheet>";
 
-        internal const string StartDimension = @"<x:dimension ref=""";
+        internal const string StartDimension = "<x:dimension ref=\"";
         internal const string DimensionPlaceholder = "                              />";
-        internal static string Dimension(string dimensionRef)
-            => $"{StartDimension}{dimensionRef}\"/>";
+        internal static string Dimension(string dimensionRef) => $"{StartDimension}{dimensionRef}\" />";
 
         internal const string StartSheetViews = "<x:sheetViews>";
         internal const string EndSheetViews = "</x:sheetViews>";

src/MiniExcel/OpenXml/ExcelOpenXmlSheetWriter.Async.cs

@@ -77,9 +77,28 @@ namespace MiniExcelLibs.OpenXml
             await writer.WriteAsync(ExcelXml.EmptySheetXml);
         }
 
+        private async Task<long> WriteDimensionPlaceholderAsync(MiniExcelAsyncStreamWriter writer)
+        {
+            var dimensionPlaceholderPostition = await writer.WriteAndFlushAsync(WorksheetXml.StartDimension);
+            await writer.WriteAsync(WorksheetXml.DimensionPlaceholder); // end of code will be replaced
+
+            return dimensionPlaceholderPostition;
+        }
+
+        private async Task WriteDimensionAsync(MiniExcelAsyncStreamWriter writer, int maxRowIndex, int maxColumnIndex, long placeholderPosition)
+        {
+            // Flush and save position so that we can get back again.
+            var position = await writer.FlushAsync();
+
+            writer.SetPosition(placeholderPosition);
+            await writer.WriteAndFlushAsync($@"{GetDimensionRef(maxRowIndex, maxColumnIndex)}""");
+
+            writer.SetPosition(position);
+        }
+
         private async Task GenerateSheetByIDataReaderAsync(MiniExcelAsyncStreamWriter writer, IDataReader reader)
         {
-            long dimensionWritePosition = 0;
+            long dimensionPlaceholderPostition = 0;
             await writer.WriteAsync(WorksheetXml.StartWorksheet);
             var yIndex = 1;
             int maxColumnIndex;
@@ -87,8 +106,7 @@ namespace MiniExcelLibs.OpenXml
             {
                 if (_configuration.FastMode)
                 {
-                    dimensionWritePosition = await writer.WriteAndFlushAsync(WorksheetXml.StartDimension);
-                    await writer.WriteAsync(WorksheetXml.DimensionPlaceholder); // end of code will be replaced
+                    dimensionPlaceholderPostition = await WriteDimensionPlaceholderAsync(writer);
                 }
 
                 var props = new List<ExcelColumnInfo>();
@@ -139,8 +157,7 @@ namespace MiniExcelLibs.OpenXml
 
             if (_configuration.FastMode)
             {
-                writer.SetPosition(dimensionWritePosition);
-                await writer.WriteAndFlushAsync($@"{GetDimensionRef(maxRowIndex, maxColumnIndex)}""");
+                await WriteDimensionAsync(writer, maxRowIndex, maxColumnIndex, dimensionPlaceholderPostition);
             }
         }
 
@@ -210,14 +227,12 @@ namespace MiniExcelLibs.OpenXml
 
             await writer.WriteAsync(WorksheetXml.StartWorksheetWithRelationship);
 
-            long dimensionWritePosition = 0;
+            long dimensionPlaceholderPostition = 0;
 
             // We can write the dimensions directly if the row count is known
             if (_configuration.FastMode && rowCount == null)
             {
-                // Write a placeholder for the table dimensions and save thee position for later
-                dimensionWritePosition = await writer.WriteAndFlushAsync(WorksheetXml.StartDimension);
-                await writer.WriteAsync(WorksheetXml.DimensionPlaceholder);
+                dimensionPlaceholderPostition = await WriteDimensionPlaceholderAsync(writer);
             }
             else
             {
@@ -269,9 +284,7 @@ namespace MiniExcelLibs.OpenXml
             // The dimension has already been written if row count is defined
             if (_configuration.FastMode && rowCount == null)
             {
-                // Seek back and write the dimensions of the table
-                writer.SetPosition(dimensionWritePosition);
-                await writer.WriteAndFlushAsync($@"{GetDimensionRef(maxRowIndex, maxColumnIndex)}""");
+                await WriteDimensionAsync(writer, maxRowIndex, maxColumnIndex, dimensionPlaceholderPostition);
             }
         }
 

src/MiniExcel/OpenXml/ExcelOpenXmlSheetWriter.cs

@@ -109,19 +109,36 @@ namespace MiniExcelLibs.OpenXml
             writer.Write(ExcelXml.EmptySheetXml);
         }
 
+        private long WriteDimensionPlaceholder(MiniExcelStreamWriter writer)
+        {
+            var dimensionPlaceholderPostition = writer.WriteAndFlush(WorksheetXml.StartDimension);
+            writer.Write(WorksheetXml.DimensionPlaceholder); // end of code will be replaced
+
+            return dimensionPlaceholderPostition;
+        }
+
+        private void WriteDimension(MiniExcelStreamWriter writer, int maxRowIndex, int maxColumnIndex, long placeholderPosition)
+        {
+            // Flush and save position so that we can get back again.
+            var position = writer.Flush();
+
+            writer.SetPosition(placeholderPosition);
+            writer.WriteAndFlush($@"{GetDimensionRef(maxRowIndex, maxColumnIndex)}""");
+
+            writer.SetPosition(position);
+        }
+
         private void GenerateSheetByIDataReader(MiniExcelStreamWriter writer, IDataReader reader)
         {
-            long dimensionWritePosition = 0;
+            long dimensionPlaceholderPosition = 0;
             writer.Write(WorksheetXml.StartWorksheet);
             var yIndex = 1;
             int maxColumnIndex;
             int maxRowIndex;
             {
-
                 if (_configuration.FastMode)
                 {
-                    dimensionWritePosition = writer.WriteAndFlush(WorksheetXml.StartDimension);
-                    writer.Write(WorksheetXml.DimensionPlaceholder); // end of code will be replaced
+                    dimensionPlaceholderPosition = WriteDimensionPlaceholder(writer);
                 }
 
                 var props = new List<ExcelColumnInfo>();
@@ -177,8 +194,7 @@ namespace MiniExcelLibs.OpenXml
 
             if (_configuration.FastMode)
             {
-                writer.SetPosition(dimensionWritePosition);
-                writer.WriteAndFlush($@"{GetDimensionRef(maxRowIndex, maxColumnIndex)}""");
+                WriteDimension(writer, maxRowIndex, maxColumnIndex, dimensionPlaceholderPosition);
             }
         }
 
@@ -248,14 +264,12 @@ namespace MiniExcelLibs.OpenXml
 
             writer.Write(WorksheetXml.StartWorksheetWithRelationship);
 
-            long dimensionWritePosition = 0;
+            long dimensionPlaceholderPostition = 0;
 
             // We can write the dimensions directly if the row count is known
             if (_configuration.FastMode && rowCount == null)
             {
-                // Write a placeholder for the table dimensions and save thee position for later
-                dimensionWritePosition = writer.WriteAndFlush(WorksheetXml.StartDimension);
-                writer.Write(WorksheetXml.DimensionPlaceholder);
+                dimensionPlaceholderPostition = WriteDimensionPlaceholder(writer);
             }
             else
             {
@@ -310,9 +324,7 @@ namespace MiniExcelLibs.OpenXml
             // The dimension has already been written if row count is defined
             if (_configuration.FastMode && rowCount == null)
             {
-                // Seek back and write the dimensions of the table
-                writer.SetPosition(dimensionWritePosition);
-                writer.WriteAndFlush($@"{GetDimensionRef(maxRowIndex, maxColumnIndex)}""");
+                WriteDimension(writer, maxRowIndex, maxColumnIndex, dimensionPlaceholderPostition);
             }
         }
 

tests/MiniExcelTests/MiniExcelIssueTests.cs

@@ -3734,5 +3734,82 @@ MyProperty4,MyProperty1,MyProperty5,MyProperty2,MyProperty6,,MyProperty3
             MiniExcel.SaveAs( path, values, excelType: ExcelType.XLSX, configuration: config, overwriteFile: true );
             
         }
+
+        private class Issue658TestData
+        {
+            public string FirstName { get; set; }
+            public string LastName { get; set; }
+        }
+
+        /// <summary>
+        /// https://github.com/mini-software/MiniExcel/issues/658
+        /// </summary>
+        [Fact]
+        public void Issue_658()
+        {
+            static IEnumerable<Issue658TestData> GetTestData()
+            {
+                yield return new() { FirstName = "Unit", LastName = "Test" };
+                yield return new() { FirstName = "Unit1", LastName = "Test1" };
+                yield return new() { FirstName = "Unit2", LastName = "Test2" };
+            }
+
+            using var memoryStream = new MemoryStream();
+            var testData = GetTestData();
+            memoryStream.SaveAs(testData, configuration: new OpenXmlConfiguration
+            {
+                FastMode = true,
+            });
+
+            memoryStream.Position = 0;
+
+            var queryData = memoryStream.Query<Issue658TestData>().ToList();
+
+            Assert.Equal(testData.Count(), queryData.Count);
+
+            var i = 0;
+            foreach (var data in testData)
+            {
+                Assert.Equal(data.FirstName, queryData[i].FirstName);
+                Assert.Equal(data.LastName, queryData[i].LastName);
+                i++;
+            }
+        }
+
+        /// <summary>
+        /// https://github.com/mini-software/MiniExcel/issues/658
+        /// </summary>
+        /// <returns></returns>
+        [Fact]
+        public async Task Issue_658_async()
+        {
+            static IEnumerable<Issue658TestData> GetTestData()
+            {
+                yield return new() { FirstName = "Unit", LastName = "Test" };
+                yield return new() { FirstName = "Unit1", LastName = "Test1" };
+                yield return new() { FirstName = "Unit2", LastName = "Test2" };
+            }
+
+            using var memoryStream = new MemoryStream();
+            var testData = GetTestData();
+            await memoryStream.SaveAsAsync(testData, configuration: new OpenXmlConfiguration
+            {
+                FastMode = true,
+            });
+
+            memoryStream.Position = 0;
+
+            var queryData = (await memoryStream.QueryAsync<Issue658TestData>()).ToList();
+
+            Assert.Equal(testData.Count(), queryData.Count);
+
+            var i = 0;
+            foreach (var data in testData)
+            {
+                Assert.Equal(data.FirstName, queryData[i].FirstName);
+                Assert.Equal(data.LastName, queryData[i].LastName);
+                i++;
+            }
+        }
     }
 }