# markdown/table-column-count

> Disallow data rows in a table from having more cells than the header row

The header row decides how many columns a table has. Extra cells are dropped when the table is rendered, so their content is silently lost.

Tables are part of GitHub Flavored Markdown, so the rule reports nothing in `markdown/commonmark`.

{/* Generated by src/codegen/lint-rule-docs.ts. Do not edit this section. */}

## Configure

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

{/* skip */}

```js eslint.config.js
import markdown from "@eslint/markdown";

export default [
  {
    files: ["**/*.md"],
    plugins: { markdown },
    language: "markdown/gfm",
    rules: { "markdown/table-column-count": "error" },
  },
];
```

It also works with `markdown/commonmark`.

{/* End of the generated section. */}

## Examples

Reported:

{/* bad */}

```md
| Name | Port |
| ---- | ---- |
| api  | 3000 | internal |
```

Not reported:

{/* good */}

```md
| Name | Port |
| ---- | ---- |
| api  | 3000 |
| web  |
```

## Options

| Option              | Default | What it does                                               |
| ------------------- | ------- | ---------------------------------------------------------- |
| `checkMissingCells` | `false` | Also report a row with fewer cells than the header row.    |

{/* bad {"options": [{ "checkMissingCells": true }]} */}

```md
| Name | Port |
| ---- | ---- |
| web  |
```