Add Performance/ChainedCallsWithNoBang rule

spec/ameba/rule/performance/chained_calls_with_no_bang_spec.cr

@@ -0,0 +1,69 @@
+require "../../../spec_helper"
+
+module Ameba::Rule::Performance
+  subject = ChainedCallsWithNoBang.new
+
+  describe ChainedCallsWithNoBang do
+    it "passes if there is no potential performance improvements" do
+      source = Source.new %(
+        (1..3).select { |e| e > 1 }.sort!
+        (1..3).select { |e| e > 1 }.sort_by!(&.itself)
+        (1..3).select { |e| e > 1 }.uniq!
+        (1..3).select { |e| e > 1 }.shuffle!
+        (1..3).select { |e| e > 1 }.reverse!
+        (1..3).select { |e| e > 1 }.rotate!
+      )
+      subject.catch(source).should be_valid
+    end
+
+    it "reports if there is select followed by reverse" do
+      source = Source.new %(
+        [1, 2, 3].select { |e| e > 1 }.reverse
+      )
+      subject.catch(source).should_not be_valid
+    end
+
+    it "reports if there is select followed by reverse followed by other call" do
+      source = Source.new %(
+        [1, 2, 3].select { |e| e > 2 }.reverse.size
+      )
+      subject.catch(source).should_not be_valid
+    end
+
+    context "properties" do
+      it "allows to configure `call_names`" do
+        source = Source.new %(
+          [1, 2, 3].select { |e| e > 2 }.reverse
+        )
+        rule = ChainedCallsWithNoBang.new
+        rule.call_names = %w(uniq)
+        rule.catch(source).should be_valid
+      end
+    end
+
+    it "reports rule, pos and message" do
+      source = Source.new path: "source.cr", code: <<-CODE
+        [1, 2, 3].select { |e| e > 1 }.reverse
+        CODE
+
+      subject.catch(source).should_not be_valid
+      source.issues.size.should eq 1
+
+      issue = source.issues.first
+      issue.rule.should_not be_nil
+      issue.location.to_s.should eq "source.cr:1:32"
+      issue.end_location.to_s.should eq "source.cr:1:39"
+
+      issue.message.should eq "Use bang method variant `reverse!` after chained `select` call"
+    end
+
+    context "macro" do
+      it "doesn't report in macro scope" do
+        source = Source.new %(
+          {{ [1, 2, 3].select { |e| e > 2  }.reverse }}
+        )
+        subject.catch(source).should be_valid
+      end
+    end
+  end
+end