Merge pull request #197 from crystal-ameba/feature/any-instead-of-empty

Add Performance/AnyInsteadOfEmpty rule

spec/ameba/ast/scope_spec.cr

@@ -51,7 +51,7 @@ module Ameba::AST
     it "adds a new variable to the scope" do
       scope = Scope.new as_node("")
       scope.add_variable(Crystal::Var.new "foo")
-      scope.variables.any?.should be_true
+      scope.variables.empty?.should be_false
     end
   end
 

spec/ameba/ast/variabling/variable_spec.cr

@@ -48,7 +48,7 @@ module Ameba::AST
       it "assigns the variable (creates a new assignment)" do
         variable = Variable.new(var_node, scope)
         variable.assign(assign_node, scope)
-        variable.assignments.any?.should be_true
+        variable.assignments.empty?.should be_false
       end
 
       it "can create multiple assignments" do
@@ -64,7 +64,7 @@ module Ameba::AST
         variable = Variable.new(var_node, scope)
         variable.assign(as_node("foo=1"), scope)
         variable.reference(var_node, scope)
-        variable.references.any?.should be_true
+        variable.references.empty?.should be_false
       end
 
       it "adds a reference to the scope" do

spec/ameba/rule/performance/any_instead_of_empty_spec.cr

@@ -0,0 +1,46 @@
+require "../../../spec_helper"
+
+module Ameba::Rule::Performance
+  subject = AnyInsteadOfEmpty.new
+
+  describe AnyInsteadOfEmpty do
+    it "passes if there is no potential performance improvements" do
+      source = Source.new %(
+        [1, 2, 3].any?(&.zero?)
+        [1, 2, 3].any?(String)
+        [1, 2, 3].any?(1..3)
+        [1, 2, 3].any? { |e| e > 1 }
+      )
+      subject.catch(source).should be_valid
+    end
+
+    it "reports if there is any? call without a block nor argument" do
+      source = Source.new %(
+        [1, 2, 3].any?
+      )
+      subject.catch(source).should_not be_valid
+    end
+
+    context "macro" do
+      it "reports in macro scope" do
+        source = Source.new %(
+          {{ [1, 2, 3].any? }}
+        )
+        subject.catch(source).should_not be_valid
+      end
+    end
+
+    it "reports rule, pos and message" do
+      source = Source.new path: "source.cr", code: %(
+        [1, 2, 3].any?
+      )
+      subject.catch(source).should_not be_valid
+      issue = source.issues.first
+
+      issue.rule.should_not be_nil
+      issue.location.to_s.should eq "source.cr:1:11"
+      issue.end_location.to_s.should eq "source.cr:1:15"
+      issue.message.should eq "Use `!{...}.empty?` instead of `{...}.any?`"
+    end
+  end
+end