New rule: empty ensure

spec/ameba/rule/empty_ensure_spec.cr

@@ -0,0 +1,68 @@
+require "../../spec_helper"
+
+module Ameba::Rule
+  describe EmptyEnsure do
+    subject = EmptyEnsure.new
+
+    it "passes if there is no empty ensure blocks" do
+      s = Source.new %(
+        def some_method
+          do_some_stuff
+        ensure
+          do_something_else
+        end
+
+        begin
+          do_some_stuff
+        ensure
+          do_something_else
+        end
+
+        def method_with_rescue
+        rescue
+        ensure
+          nil
+        end
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "fails if there is an empty ensure in method" do
+      s = Source.new %(
+        def method
+          do_some_stuff
+        ensure
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "fails if there is an empty ensure in a block" do
+      s = Source.new %(
+        begin
+          do_some_stuff
+        ensure
+          # nothing here
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "reports rule, pos and message" do
+      s = Source.new %(
+        begin
+          do_some_stuff
+        rescue
+          do_some_other_stuff
+        ensure
+        end
+      ), "source.cr"
+      subject.catch(s).should_not be_valid
+      error = s.errors.first
+
+      error.rule.should_not be_nil
+      error.location.to_s.should eq "source.cr:3:11"
+      error.message.should eq "Empty `ensure` block detected"
+    end
+  end
+end