The JavaScript exception "mismatched placement" occurs when a private getter and setter are mismatched in whether or not they are static.
Message
SyntaxError: Identifier '#x' has already been declared (V8-based)
SyntaxError: getter and setter for private name #x should either be both static or non-static (Firefox)
SyntaxError: Cannot declare a private non-static getter if there is a static private setter with used name. (Safari)
Error type
What went wrong?
Private getters and setters for the same name must either be both static, or both non-static. This limitation does not exist for public methods.
Examples
Mismatched placement
class Test {
static set #foo(_) {}
get #foo() {}
}
// SyntaxError: getter and setter for private name #foo should either be both static or non-static
Since foo is private, the methods must be either both static:
class Test {
static set #foo(_) {}
static get #foo() {}
}
or non-static:
class Test {
set #foo(_) {}
get #foo() {}
}