Fix edge cases in Kernel#raise

Author: andrykonchin

core/kernel/raise_spec.rb

@@ -44,7 +44,53 @@
 
   it "raises an ArgumentError when only cause is given" do
     cause = StandardError.new
-    -> { raise(cause: cause) }.should raise_error(ArgumentError)
+    -> { raise(cause: cause) }.should raise_error(ArgumentError, "only cause is given with no arguments")
+  end
+
+  it "raises an ArgumentError when only cause is given even if it has nil value" do
+    -> { raise(cause: nil) }.should raise_error(ArgumentError, "only cause is given with no arguments")
+  end
+
+  it "raises an ArgumentError when given cause is not an instance of Exception" do
+    -> { raise "message", cause: Object.new }.should raise_error(TypeError, "exception object expected")
+  end
+
+  it "doesn't raise an ArgumentError when given cause is nil" do
+    -> { raise "message", cause: nil }.should raise_error(RuntimeError, "message")
+  end
+
+  it "allows cause equal an exception" do
+    e = RuntimeError.new("message")
+    -> { raise e, cause: e }.should raise_error(e)
+  end
+
+  it "doesn't set given cause when it equals an exception" do
+    e = RuntimeError.new("message")
+
+    begin
+      raise e, cause: e
+    rescue
+    end
+
+    e.cause.should == nil
+  end
+
+  it "raises ArgumentError when exception is part of the cause chain" do
+    -> {
+      begin
+        raise "Error 1"
+      rescue => e1
+        begin
+          raise "Error 2"
+        rescue => e2
+          begin
+            raise "Error 3"
+          rescue => e3
+            raise e1, cause: e3
+          end
+        end
+      end
+    }.should raise_error(ArgumentError, "circular causes")
   end
 
   it "re-raises a rescued exception" do
@@ -106,6 +152,57 @@
       e.cause.should == e4
     end
   end
+
+  it "re-raises a previously rescued exception without overwriting the cause when it's explicitly specified with :cause option and has nil value" do
+    begin
+      begin
+        begin
+          begin
+            raise "Error 1"
+          rescue => e1
+            raise "Error 2"
+          end
+        rescue => e2
+          raise "Error 3"
+        end
+      rescue
+        e2.cause.should == e1
+        raise e2, cause: nil
+      end
+    rescue => e
+      e.cause.should == e1
+    end
+  end
+
+  it "re-raises a previously rescued exception without setting a cause implicitly" do
+    begin
+      begin
+        raise "Error 1"
+      rescue => e1
+        raise
+      end
+    rescue => e
+      e.should == e1
+      e.cause.should == nil
+    end
+  end
+
+  it "re-raises a previously rescued exception that has a cause without setting a cause implicitly" do
+    begin
+      begin
+        raise "Error 1"
+      rescue => e1
+        begin
+          raise "Error 2"
+        rescue => e2
+          raise
+        end
+      end
+    rescue => e
+      e.should == e2
+      e.cause.should == e1
+    end
+  end
 end
 
 describe "Kernel#raise" do

shared/kernel/raise.rb

@@ -49,21 +49,6 @@ def initialize(data)
     end
   end
 
-  it "does not allow message and extra keyword arguments" do
-    data_error = Class.new(StandardError) do
-      attr_reader :data
-      def initialize(data)
-        @data = data
-      end
-    end
-
-    -> { @object.raise(data_error, {a: 1}, b: 2) }.should raise_error(StandardError) do |e|
-      [TypeError, ArgumentError].should.include?(e.class)
-    end
-
-    -> { @object.raise(data_error, {a: 1}, [], b: 2) }.should raise_error(ArgumentError)
-  end
-
   it "raises RuntimeError if no exception class is given" do
     -> { @object.raise }.should raise_error(RuntimeError, "")
   end
@@ -74,7 +59,7 @@ def initialize(data)
   end
 
   it "raises a RuntimeError if string given" do
-    -> { @object.raise("a bad thing") }.should raise_error(RuntimeError)
+    -> { @object.raise("a bad thing") }.should raise_error(RuntimeError, "a bad thing")
   end
 
   it "passes no arguments to the constructor when given only an exception class" do
@@ -86,19 +71,32 @@ def initialize
   end
 
   it "raises a TypeError when passed a non-Exception object" do
-    -> { @object.raise(Object.new) }.should raise_error(TypeError)
+    -> { @object.raise(Object.new) }.should raise_error(TypeError, "exception class/object expected")
+    -> { @object.raise(Object.new, "message") }.should raise_error(TypeError, "exception class/object expected")
+    -> { @object.raise(Object.new, "message", []) }.should raise_error(TypeError, "exception class/object expected")
   end
 
   it "raises a TypeError when passed true" do
-    -> { @object.raise(true) }.should raise_error(TypeError)
+    -> { @object.raise(true) }.should raise_error(TypeError, "exception class/object expected")
   end
 
   it "raises a TypeError when passed false" do
-    -> { @object.raise(false) }.should raise_error(TypeError)
+    -> { @object.raise(false) }.should raise_error(TypeError, "exception class/object expected")
   end
 
   it "raises a TypeError when passed nil" do
-    -> { @object.raise(nil) }.should raise_error(TypeError)
+    -> { @object.raise(nil) }.should raise_error(TypeError, "exception class/object expected")
+  end
+
+  it "raises TypeError when passed a non-Exception object but it responds to #exception method that doesn't return an instance of Exception class" do
+    e = Object.new
+    def e.exception
+      Array
+    end
+
+    -> {
+      @object.raise e
+    }.should raise_error(TypeError, "exception object expected")
   end
 
   it "re-raises a previously rescued exception without overwriting the backtrace" do