Support for markdown in the rule's message report

[Newbie012]

Current Behavior:

While writing custom ESLint rules, I discovered that it's currently impossible to use markdown in the rule's message report. This means that any styled text or inline code cannot be properly formatted, reducing clarity and readability.

For instance, currently, a message report could look as follows:

context.report({
    node,
    message: 'Avoid using this in your code: const a = {};'
});

Expected Behavior:

The ESLint VScode extension should support Markdown in rule report messages to allow richer instruction and improved readability. This would enable rule authors to provide well-formatted, comprehensive instructions, including items like inline code, bullet points, etc.

Ideally, it would look like:

context.report({
    node,
    message: 'Avoid using `const a = {};` in your code.'
});

In this case, the rule message is more expressive and it leverages markdown formatting, delineating the code from the rest of the text for clarity.

[dbaeumer]

This is a limitation in VS Code itself (diagnostics can only be strings right now) and there is a feature request in VS Code to improve that. I will close the issue since things should work as soon as support gets added to VS Code.

See microsoft/vscode#54272