Add Exception signatures

stdlib/builtin/exception.rbs

@@ -122,6 +122,10 @@
 # 
 #   - fatal – impossible to rescue
 class Exception < Object
+  def self.to_tty?: () -> bool
+
+  def self.exception: (?String msg) -> self
+
   def ==: (untyped arg0) -> bool
 
   # Returns any backtrace associated with the exception. The backtrace is an
@@ -184,4 +188,6 @@ class Exception < Object
   # Returns exception’s message (or the name of the exception if no message
   # is set).
   def to_s: () -> String
+
+  def full_message: (?highlight: bool, ?order: :top | :bottom) -> String
 end

test/stdlib/Exception_test.rb

@@ -0,0 +1,24 @@
+require_relative "test_helper"
+
+class ExceptionTest < StdlibTest
+  target Exception
+  using hook.refinement
+
+  def test_full_message
+    Exception.new.full_message
+    Exception.new.full_message(highlight: true)
+    Exception.new.full_message(highlight: false)
+    Exception.new.full_message(order: :top)
+    Exception.new.full_message(order: :bottom)
+  end
+
+  def test_to_tty
+    Exception.to_tty?
+  end
+
+  def test_exception
+    Exception.exception
+    Exception.exception('test')
+    NameError.exception
+  end
+end