New rule: RedundantWithObject (#121)

spec/ameba/rule/lint/redundant_with_object_spec.cr

@@ -0,0 +1,83 @@
+require "../../../spec_helper"
+
+module Ameba::Rule::Lint
+  describe RedundantWithObject do
+    subject = RedundantWithObject.new
+
+    it "does not report if there is index argument" do
+      s = Source.new %(
+        collection.each_with_object(0) do |e, obj|
+          obj += i
+        end
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "reports if there is not index argument" do
+      s = Source.new %(
+        collection.each_with_object(0) do |e|
+          e += 1
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "reports if there is underscored index argument" do
+      s = Source.new %(
+        collection.each_with_object(0) do |e, _|
+          e += 1
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "reports if there is no args" do
+      s = Source.new %(
+        collection.each_with_object(0) do
+          puts :nothing
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "does not report if there is no block" do
+      s = Source.new %(
+        collection.each_with_object(0)
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "does not report if first argument is underscored" do
+      s = Source.new %(
+        collection.each_with_object(0) do |_, obj|
+          puts i
+        end
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "does not report if there are more than 2 args" do
+      s = Source.new %(
+        tup.each_with_object(0) do |key, value, obj|
+          puts i
+        end
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "reports rule, location and message" do
+      s = Source.new %(
+        def valid?
+          collection.each_with_object(0) do |e|
+          end
+        end
+      ), "source.cr"
+      subject.catch(s).should_not be_valid
+      issue = s.issues.first
+      issue.rule.should_not be_nil
+      issue.location.to_s.should eq "source.cr:2:14"
+      issue.end_location.to_s.should eq "source.cr:2:30"
+      issue.message.should eq "Use each instead of each_with_object"
+    end
+  end
+end