markdown/require-alt-text

The alternative text is what a screen reader reads out, and what everybody sees when the image doesn't load. Without it, those readers get nothing.

<img> elements in HTML are checked too. alt="" marks an image as decorative, so it's allowed, and so is aria-hidden="true".

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/require-alt-text": "error" },
  },
];

It also works with markdown/gfm.

Examples

Reported:

![](./dashboard.png)

![][dashboard]

<img src="./dashboard.png">

[dashboard]: ./dashboard.png

Not reported:

![The dashboard](./dashboard.png)

<img src="./dashboard.png" alt="The dashboard">

<img src="./divider.png" alt="">

<img src="./divider.png" aria-hidden="true">