DisableSyntax.md

layout	id	title
docs	DisableSyntax	DisableSyntax

This rule reports errors when a "disallowed" syntax is used. This is a syntactic rule, which means it does not require compilation to run unlike the Disable rule.

Example:

MyCode.scala:10: error: [DisableSyntax.throw] exceptions should be avoided,
                        consider encoding the error in the return type instead
  throw new IllegalArgumentException
  ^^^^^

Configuration

By default, this rule does not disable any particular syntax, every setting is opt-in.

import scalafix.internal.rule._

println(
scalafix.website.rule("DisableSyntax", DisableSyntaxConfig.default)
)

Regex

Regex patterns have 3 available ways to be configured. The example below shows 1 of each way.

DisableSyntax.regex = [
  {
    id = offensive
    pattern = "[Pp]imp"
    message = "Please consider a less offensive word than ${0} such as Extension"
  }
  "Await\\.result"
  {
    id = magicNumbers
    regex = {
      pattern = "(?:(?:[,(]\\s)|(?:^\\s*))+(\\d+(\\.\\d+)?)"
      captureGroup = 1
    }
    message = "Numbers ({$1} in this instance) should always have a named parameter attached, or be assigned to a val."
  }
]

1. The first way has a simple object providing an id, pattern, and message.
2. The second way is just the pattern. When this is used, the id is set equal to the pattern, and a generic message is provided for you.
3. The third way allows you to specify what capture-group the problematic thing is in, in case your regex is complicated.

Error Messages

Error messages have access to the capture groups of the regex. Simply use {$n} where n is the index of the capture group you wish to appear in that part of the message.

You can see this used in the 3rd example.