# parameter-naming

Source: https://apigenie.pl/docs/linter/asyncapi/rules/parameter-naming

This rule checks all channel parameters in an AsyncAPI document and warns if
their names do not adhere to the specified naming convention.

## Rule Details

The `parameter-naming` rule is designed to ensure that the name of each
channel parameter adheres to a specific naming convention. In AsyncAPI 3.x,
the name of a parameter is its key in the `parameters` map, which is the same
name that appears between braces in the channel address.

The rule checks the parameters of every channel (in the root `channels` map
and in `components/channels`), as well as the entries of
`components/parameters`. For every parameter whose name is not in the
expected convention, it reports `Parameter should be named <name>`, where
`<name>` is the parameter name converted to that convention.

The recognised naming conventions are:

- `const` - THIS_IS_CONST_CASE
- `camel` - thisIsCamelCase, also with acronyms (userID)
- `camel-strict` - thisIsCamelCase, but no two capitals in a row (userId, not userID)
- `kebab` - this-is-kebab-case
- `pascal` - ThisIsPascalCase, also with acronyms (HTTPServer)
- `pascal-strict` - ThisIsPascalCase, but no two capitals in a row (HttpServer, not HTTPServer)
- `header` - This-Is-Header-Case
- `snake` - this_is_snake_case

The default convention is `snake`.

Unlike OpenAPI, AsyncAPI parameters have no location (path, query, header or
cookie), so a single convention applies to all of them.

## Configuration

The configuration block can be a string or an object.

If it is a string, its value is the name of the naming convention (see the
"Rule Details" section for a list of recognized names).

If it is an object, it must contain the `default` property, whose value is
the name of the naming convention. Other properties are ignored.

**Configuration Example**. The following two examples are equivalent. They
specify that the expected naming convention for all parameters is
`camelCase`.

```yaml
version: "1.0"
commands:
  lint:
    asyncapi:
      rules:
        parameter-naming: [warning, camel]
```

```yaml
version: "1.0"
commands:
  lint:
    asyncapi:
      rules:
        parameter-naming:
          - warning
          - default: camel
```

## Examples

**Good**. With the default configuration.

```yaml
asyncapi: 3.0.0
info:
  title: User Events
  version: 1.0.0
channels:
  userSignedUp:
    address: users.{user_id}.signedUp
    parameters:
      user_id:
        description: Identifier of the user.
```

**Bad**. With the default configuration, the linter reports
`Parameter should be named user_id`.

```yaml
asyncapi: 3.0.0
info:
  title: User Events
  version: 1.0.0
channels:
  userSignedUp:
    address: users.{userId}.signedUp
    parameters:
      userId:
        description: Identifier of the user.
```

## When Not to Use It

We recommend to always enable this rule.

## Compatibility

This rule is compatible with AsyncAPI 3.x documents. AsyncAPI 2.x documents
are rejected by the reader and are not linted.