markdown/fenced-code-language

A fenced code block without a language gets no syntax highlighting, and tools that extract code blocks by language skip it. Indented code blocks can't have a language, so they're ignored.

Configure

Off by default. It needs an ESLint config that says which files are in the language:

import markdown from "@eslint/markdown";

export default [
  {
    files: ["**/*.md"],
    plugins: { markdown },
    language: "markdown/commonmark",
    rules: { "markdown/fenced-code-language": "error" },
  },
];

It also works with markdown/gfm.

Examples

Reported:

```
const port = 3000;
```

Not reported:

```js
const port = 3000;
```

Options

```javascript
const port = 3000;
```

```js
const port = 3000;
```