fix: GenerateVisualizationHtml produces non-empty dataSources when called without snapshots

[Copilot]

VisualizationHtmlBuilder.GenerateVisualizationHtml emitted dataSources = [] whenever no snapshots argument was passed, causing the page script to immediately throw TypeError: Cannot read properties of undefined (reading 'statistics') at dataSources[0].

Changes

• VisualizationHtmlBuilder.cs

  • When snapshotList is empty, route through a new BuildDataSourcesJsonFromAnalysisResult fallback instead of BuildDataSourcesJson, producing a single-element dataSources array with description "Runtime" and metadata derived from the passed-in analysisResult.
  • The fallback emits the same JSON shape as snapshot-based entries (metadata, analysisResult, statistics, diagrams, allChainFlowCharts, allAggregateRelationDiagrams), so the page script works identically regardless of which path produced the data.

• VisualizationHtmlBuilderTests.cs

  • Added GenerateVisualizationHtml_WithNoSnapshots_ShouldContainNonEmptyDataSources covering the previously broken call signature.

Minimal working call (now works without workaround)

var analysisResult = CodeFlowAnalysisHelper.GetResultFromAssemblies(assemblies);
var html = VisualizationHtmlBuilder.GenerateVisualizationHtml(analysisResult);
// dataSources now contains one "Runtime" entry — page no longer crashes
return Results.Content(html, "text/html; charset=utf-8");

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Bug] GenerateVisualizationHtml 在未传入 snapshots 时生成空 dataSources，导致可视化页面脚本报错</issue_title>
<issue_description>

环境

• 包：NetCorePal.Extensions.CodeAnalysis 3.2.1-preview.1.2603240625
• 目标框架：net10.0

目前解决方案

  // Code analysis endpoint
app.MapGet("/code-analysis", () =>
{
   Assembly[] assemblies =
   [
       typeof(Program).Assembly,
       typeof(ApplicationDbContext).Assembly,
       typeof(Ncp.Admin.Domain.AggregatesModel.UserAggregate.User).Assembly
   ];
   var analysisResult = CodeFlowAnalysisHelper.GetResultFromAssemblies(assemblies);
   // NetCorePal 3.2.1-preview：GenerateVisualizationHtml 仅从 snapshots 构建 dataSources；
   // 未传入快照时 dataSources 为 []，页面脚本访问 dataSources[0].statistics 会抛错。
   var snapshots = CodeFlowAnalysisSnapshotHelper.ScanSnapshotsFromAssemblies(assemblies);
   snapshots.Add(CodeFlowAnalysisSnapshotHelper.CreateSnapshot(
       CodeFlowAnalysisHelper.GetAllMetadataAttributes(assemblies).ToArray(),
       "Runtime"));
   var html = VisualizationHtmlBuilder.GenerateVisualizationHtml(analysisResult, snapshots: snapshots);
   return Results.Content(html, "text/html; charset=utf-8");
});

</issue_description>

<agent_instructions>修复该bug</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes [Bug] GenerateVisualizationHtml 在未传入 snapshots 时生成空 dataSources，导致可视化页面脚本报错 #350

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[Copilot]

Pull request overview

Fixes a runtime crash in the embedded visualization page by ensuring VisualizationHtmlBuilder.GenerateVisualizationHtml always emits a non-empty dataSources array even when no snapshots are provided.

Changes:

• Add a runtime fallback path that builds a single dataSources entry directly from analysisResult when the snapshot list is empty.
• Add a unit test that covers calling GenerateVisualizationHtml(result) without passing snapshots.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/NetCorePal.Extensions.CodeAnalysis/VisualizationHtmlBuilder.cs	Adds a runtime fallback dataSources builder so the page script can safely read dataSources[0].
test/NetCorePal.Extensions.CodeAnalysis.UnitTests/VisualizationHtmlBuilderTests.cs	Adds a regression test ensuring dataSources is non-empty and contains expected fields without snapshots.

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[Copilot]

BuildDataSourcesJsonFromAnalysisResult duplicates most of the JSON assembly logic from BuildDataSourcesJson (mermaid generation + dataSource object shape). This increases drift risk if the dataSource schema changes in the future (one path may be updated and the other forgotten). Consider extracting a shared helper that builds a single dataSource entry from (analysisResult, metadata) and have both code paths call it (looping for snapshots vs. one-off for runtime).

[witskeeper]

@copilot apply changes based on this feedback

[Copilot]

Done in 7514183. Extracted a shared BuildSingleDataSourceEntryJson(analysisResult, version, timestamp, description, hash, nodeCount, relationshipCount) helper. Both BuildDataSourcesJson (snapshot loop) and BuildDataSourcesJsonFromAnalysisResult (runtime fallback) now delegate to it — all JSON assembly and EscapeJavaScript calls live in one place.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

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