# no-bitwise

> Disallow bitwise operators

Most application code never needs `&`, `|`, `^`, `~`, `<<`, `>>` or `>>>`, so a single `&` or `|` is usually a typo for `&&` or `||`. The code still runs, but it evaluates both sides every time and gives a number instead of one of the operands.

The assignment forms such as `|=` and `<<=` are reported too.

{/* 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]
"no-bitwise" = "error" # or "warn"
```

Every option, set to its default:

```toml bunfig.toml
[lint.rules]
"no-bitwise" = ["error", {
  allow = [], # list of strings
  int32Hint = false,
}]
```

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

## Examples

Reported:

{/* bad */}
```js
if (user.active & user.verified) {
  grant(user);
}
```

Not reported:

{/* good */}
```js
if (user.active && user.verified) {
  grant(user);
}
```

## Options

```toml bunfig.toml
[lint.rules]
no-bitwise = ["error", { allow = ["&", "|"] }]
```

| Option | Default | What it does |
| --- | --- | --- |
| `allow` | `[]` | Operators that aren't reported. |
| `int32Hint` | `false` | Allow `value \| 0`, a way to cut a number down to a 32-bit integer. |

With `allow: ["&", "|"]`, this isn't reported:

{/* good {"options": [{"allow": ["&", "|"]}]} */}
```js
const mode = READ | WRITE;
const canWrite = (mode & WRITE) !== 0;
```

With `int32Hint`, neither is this:

{/* good {"options": [{"int32Hint": true}]} */}
```js
const whole = price | 0;
```

Any other number is still reported:

{/* bad {"options": [{"int32Hint": true}]} */}
```js
const odd = price | 1;
```

## When not to use it

Code that works with flags, binary formats, hashes or colors needs these operators. Turn the rule off for those files, or list the operators you use in `allow`.