# require-array-join-separator

Require an explicit array join separator

`Array.join()` silently selects a comma as its separator.
Instead, you SHOULD pass the intended separator explicitly.

- Category: style
- Level: warning
- Fix: automatic
- Scope: module

## Reported

```ds title="main.ds"
function commaSeparated(values: string[]): string {
    return values.join();
}
```

## Accepted

```ds title="main.ds"
function commaSeparated(values: string[]): string {
    return values.join(",");
}
```

## Prior art

- [eslint-plugin-unicorn · require-array-join-separator](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/require-array-join-separator.md)

[language/linter/src/rules/style/require_array_join_separator.rs:8](https://github.com/destack-sh/destack/blob/main/language/linter/src/rules/style/require_array_join_separator.rs#L8)