Markdown Link Testing

A minimal C++ project used to reproduce Visual Studio's incorrect handling of certain markdown links. The C++ side is just a hello-world program (src/main.cpp); the interesting part lives in docs/.

The problem

docs/doc-a.md and docs/doc-b.md contain a set of markdown links. All of them work correctly on GitHub. In Visual Studio's markdown preview, two kinds of links are broken:

1. Cross-file anchor links (docs/doc-b.md) — otherfile.md#heading. When a link has a #fragment, Visual Studio ignores the file path entirely and resolves the fragment against the current document — it never navigates to the named file. So a "cross-file" link jumps only if the current file happens to contain that id (landing on the wrong file's heading), and otherwise does nothing. Only a plain otherfile.md link with no fragment actually crosses to another file. No format works around this; the file path is discarded whenever a fragment is present.
2. Same-file anchors whose GitHub heading id differs from VS's (docs/doc-a.md). VS's preview generates heading ids that are not GitHub-compatible, so a correct GitHub anchor finds nothing in VS. The two divergences:
   • A leading number is dropped by VS (## 5 Reasons → reasons, not 5-reasons). A number in the middle of a title is fine in both.
   • A dot is removed by GitHub but kept by VS (## Version 2.0 Notes → version-20-notes on GitHub, version-2.0-notes in VS).

Presumed cause: we can't see Visual Studio's internals, but its preview behaves exactly as the Markdig parser does when run without its AutoIdentifierOptions.GitHub option — every observed id is reproduced that way. So VS appears to use a Markdig-like algorithm with non-GitHub identifiers; this is inferred from behavior, not confirmation that VS uses Markdig.

Each link in the docs is labeled with what it tests and whether it works, so you can click through them in Visual Studio and compare against GitHub.

Reproduced in Visual Studio 2022 and Visual Studio 2026.

Opening in Visual Studio

No generators or extra build tools are required — the Visual Studio solution is checked in. Just open it from the project root:

start MarkdownLinkTesting.sln

or double-click MarkdownLinkTesting.sln in File Explorer.

The two markdown files (and this README) are included in the solution, so you can open them from Solution Explorer and click the links directly.

If Visual Studio offers to retarget the project to a newer platform toolset or Windows SDK, you can accept or ignore it — the project is only a hello-world program and does not need to build to demonstrate the issue.