1 files changed, 22 insertions, 0 deletions
diff --git a/spec/ruby/core/proc/shared/compose.rb b/spec/ruby/core/proc/shared/compose.rb
new file mode 100644
index 0000000000..3d3f3b310d
--- /dev/null
+++ b/spec/ruby/core/proc/shared/compose.rb
@@ -0,0 +1,22 @@
+describe :proc_compose, shared: true do
+  it "raises TypeError if passed not callable object" do
+    lhs = @object.call
+    not_callable = Object.new
+
+    -> {
+      lhs.send(@method, not_callable)
+    }.should raise_error(TypeError, "callable object is expected")
+
+  end
+
+  it "does not try to coerce argument with #to_proc" do
+    lhs = @object.call
+
+    succ = Object.new
+    def succ.to_proc(s); s.succ; end
+
+    -> {
+      lhs.send(@method, succ)
+    }.should raise_error(TypeError, "callable object is expected")
+  end
+end