JoinReport with unexpected results

[swtrse]

I do have the following Artifacts
BenchmarkDotNet.Artifacts.zip

I tried to create a joint Report

var options = new JoinReportHtmlOptions
              {
	              Title = "Benchmark of Collection Item Manipulation (Mean)",
	              MainColumn = "Method",
	              GroupByColumns = ["Categories", "Prefill", "PriceRange"],
	              PivotProperty = "Runtime",
	              StatisticColumns = ["Mean"],
	              ColumnsOrder = [".NET 8.0", "NativeAOT 8.0", ".NET 9.0", "NativeAOT 9.0"],
	              OtherColumnsToSelect = ["DataType"],
	              SpectrumStatisticColumn = true,
	              HighlightGroups = true,
	              DividerMode = RenderTableDividerMode.SeparateTables,
	              HtmlWrapMode = HtmlDocumentWrapMode.RichDataTables
              };

await benchmarkSummaries.JoinReportsAndSaveAsHtmlAsync(DirectoryHelper.GetPathRelativeToProjectDirectory("Reports\\Benchmark-Mean.html"), options).ConfigureAwait(false);

The result looks like

As you can see there are additional Lines (like line 2) that I did not expect. I did experiment a bit and found out that DataType maybe the culprit.

So I changed the settings to

var options = new JoinReportHtmlOptions
              {
	              Title = "Benchmark of Collection Item Manipulation (Mean)",
	              MainColumn = "Method",
	              GroupByColumns = ["DataType", "Categories", "Prefill", "PriceRange"],
	              PivotProperty = "Runtime",
	              StatisticColumns = ["Mean"],
	              ColumnsOrder = [".NET 8.0", "NativeAOT 8.0", ".NET 9.0", "NativeAOT 9.0"],
	              SpectrumStatisticColumn = true,
	              HighlightGroups = true,
	              DividerMode = RenderTableDividerMode.SeparateTables,
	              HtmlWrapMode = HtmlDocumentWrapMode.RichDataTables
              };

await benchmarkSummaries.JoinReportsAndSaveAsHtmlAsync(DirectoryHelper.GetPathRelativeToProjectDirectory("Reports\\Benchmark-Mean.html"), options).ConfigureAwait(false);

Now I get this

This is too fragmented, but all the doubled lines are gone and the lines are exactly what I want to show.
Basically, I want Table 1 + Table 2 joined in one table and Table 3 + Table 4 joined in one table and so on....

Did I miss some settings or maybe the Join Report do have a little flaw with merging the reports?

[swtrse]

I did provide a pull request with the fix. However I did not test for side effects but for my case this is exactly what I needed.

This is the intended result

[mjebrahimi]

Thanks @swtrse. I closed this issue since you fixed it well.