# unicorn/text-encoding-identifier-case

> Enforce one spelling for the encoding names `utf8` and `ascii`

`"UTF-8"`, `"utf-8"`, `"Utf8"` and `"utf8"` all name the same encoding in most APIs. With one spelling, a search finds every use. The rule wants `"utf8"` and `"ascii"`.

In three places it wants `"utf-8"`, the name the web standards use: `new TextDecoder("utf-8")`, `<meta charset="utf-8" />` and `<form acceptCharset="utf-8">`.

The rule reports any string that's exactly one of these names, wherever it appears, and JSX text such as `<span>UTF-8</span>`. Template literals aren't checked.

`--fix` rewrites the string.

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

## Configure

Off by default. To turn it on:

```toml bunfig.toml
[lint.rules]
"unicorn/text-encoding-identifier-case" = "error" # or "warn"
```

Every option, set to its default:

```toml bunfig.toml
[lint.rules]
"unicorn/text-encoding-identifier-case" = ["error", {
  withDash = false,
}]
```

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

## Examples

Reported:

{/* bad {"count": 3} */}
```js
const text = await fs.readFile(file, "UTF-8");
const bytes = Buffer.from(name, "ASCII");
const decoder = new TextDecoder("utf8");
```

{/* bad {"count": 2} */}
```jsx
const head = <meta charset="utf8" />;
const label = <span>UTF-8</span>;
```

Not reported:

{/* good */}
```js
const text = await fs.readFile(file, "utf8");
const bytes = Buffer.from(name, "ascii");
const decoder = new TextDecoder("utf-8");
```

{/* good */}
```jsx
const head = <meta charset="utf-8" />;
const label = <span>{`UTF-8`}</span>;
```

## Options

| Option | Default | What it does |
| --- | --- | --- |
| `withDash` | `false` | Require `"utf-8"` everywhere instead of `"utf8"`. |

{/* bad {"options": [{"withDash": true}]} */}
```js
const text = await fs.readFile(file, "utf8");
```

{/* good {"options": [{"withDash": true}]} */}
```js
const text = await fs.readFile(file, "utf-8");
```