Exceptions should not be swallowed. This rule reports all instances where exceptions are caught and not correctly passed (e.g. as a cause) into a newly thrown exception. The exception types configured in ignoredExceptionTypes indicate nonexceptional outcomes. These by default configured exception types are part of Java. Therefore, Kotlin developers have to handle them by using the catch clause. For that reason, this rule ignores that these configured exception types are caught.

Noncompliant Code

fun foo() {
    try {
        // ...
    } catch(e: IOException) {
        throw MyException(e.message) // e is swallowed
    }
    try {
        // ...
    } catch(e: IOException) {
        throw MyException() // e is swallowed
    }
    try {
        // ...
    } catch(e: IOException) {
        bar() // exception is unused
    }
}

Compliant Code

fun foo() {
    try {
        // ...
    } catch(e: IOException) {
        throw MyException(e)
    }
    try {
        // ...
    } catch(e: IOException) {
        println(e) // logging is ok here
    }
}

Options

• ignoredExceptionTypes (default: ['interruptedexception', 'malformedurlexception', 'numberformatexception', 'parseexception'])

  exception types which should be ignored (both in the catch clause and body)

• allowedExceptionNameRegex (default: _|(ignore|expected).*)

  ignores too generic exception types which match this regex