New rule: EmptyLoop

spec/ameba/rule/lint/empty_loop_spec.cr

@@ -0,0 +1,88 @@
+require "../../../spec_helper"
+
+module Ameba::Rule::Lint
+  describe EmptyLoop do
+    subject = EmptyLoop.new
+
+    it "does not report if there are not empty loops" do
+      s = Source.new %(
+        a = 1
+
+        while a < 10
+          a += 1
+        end
+
+        until a == 10
+         a += 1
+        end
+
+        loop do
+          a += 1
+        end
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "reports if there is an empty while loop" do
+      s = Source.new %(
+        a = 1
+        while true
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "doesn't report if while loop has non-literals in cond block" do
+      s = Source.new %(
+        a = 1
+        while a = gets.to_s
+          # nothing here
+        end
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "reports if there is an empty until loop" do
+      s = Source.new %(
+        do_something
+        until false
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "doesn't report if until loop has non-literals in cond block" do
+      s = Source.new %(
+        until socket_open?
+        end
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "reports if there an empty loop" do
+      s = Source.new %(
+        a = 1
+        loop do
+
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "reports rule, message and location" do
+      s = Source.new %(
+        a = 1
+        loop do
+          # comment goes here
+        end
+      ), "source.cr"
+      subject.catch(s).should_not be_valid
+      s.issues.size.should eq 1
+      issue = s.issues.first
+      issue.rule.should_not be_nil
+      issue.location.to_s.should eq "source.cr:2:1"
+      issue.end_location.to_s.should eq "source.cr:4:3"
+      issue.message.should eq EmptyLoop::MSG
+    end
+  end
+end