CasePaths Documentation

Function XCTUnwrap(_:​case:​_:​file:​line:​) 

public func XCTUnwrap<Root, Case>(
  _ expression: @autoclosure () throws -> Root,
  case extract: (Root) -> Case?,
  _ message: @autoclosure () -> String = "",
  file: StaticString = #file,
  line: UInt = #line
) throws -> Case

Asserts that an enum value matches a particular case and returns the associated value.

Parameters

expression @autoclosure () throws -> Root

An enum value.
extract (Root) -> Case?

A closure that attempts to extract a particular case from the enum. You can supply a case path literal here, like '/Enum.case'.
message @autoclosure () -> String

An optional description of a failure.

Returns

The unwrapped associated value from the matched case of the enum.