RedundantNext params

spec/ameba/rule/style/redundant_next_spec.cr

@@ -11,16 +11,6 @@ module Ameba::Rule::Style
       subject.catch(s).should be_valid
     end
 
-    it "reports if there is redundant next in the block" do
-      s = Source.new %(
-        block do |v|
-          p v + 1
-          next
-        end
-      )
-      subject.catch(s).should_not be_valid
-    end
-
     it "reports if there is redundant next with argument in the block" do
       s = Source.new %(
         block do |v|
@@ -99,7 +89,7 @@ module Ameba::Rule::Style
         s = Source.new %(
           block do |a|
             a = 1
-            next
+            next a
           end
         )
         subject.catch(s).should_not be_valid
@@ -121,7 +111,7 @@ module Ameba::Rule::Style
       it "reports if there is redundant next in binary op" do
         s = Source.new %(
           block do |a|
-            a && next
+            a && next a
           end
         )
         subject.catch(s).should_not be_valid
@@ -136,7 +126,7 @@ module Ameba::Rule::Style
           block do |v|
             v + 1
           rescue e
-            next if v > 0
+            next v if v > 0
           end
         )
         subject.catch(s).should be_valid
@@ -150,7 +140,7 @@ module Ameba::Rule::Style
             next a + 2
           rescue Exception
             a + 2
-            next
+            next a
           end
         )
         subject.catch(s).should_not be_valid
@@ -175,5 +165,55 @@ module Ameba::Rule::Style
       issue.end_location.to_s.should eq "source.cr:2:12"
       issue.message.should eq "Redundant `next` detected"
     end
+
+    context "properties" do
+      context "#allow_multi_next=" do
+        it "allows multi next statements by default" do
+          s = Source.new %(
+            block do |a, b|
+              next a, b
+            end
+          )
+          subject.catch(s).should be_valid
+        end
+
+        it "allows to configure multi next statements" do
+          s = Source.new %(
+            block do |a, b|
+              next a, b
+            end
+          )
+          rule = Rule::Style::RedundantNext.new
+          rule.allow_multi_next = false
+          rule.catch(s).should_not be_valid
+          s.issues.size.should eq 1
+          s.issues.first.location.to_s.should eq ":2:3"
+        end
+      end
+
+      context "#allow_empty_next" do
+        it "allows empty next statements by default" do
+          s = Source.new %(
+            block do
+              next
+            end
+          )
+          subject.catch(s).should be_valid
+        end
+
+        it "allows to configure empty next statements" do
+          s = Source.new %(
+            block do
+              next
+            end
+          )
+          rule = Rule::Style::RedundantNext.new
+          rule.allow_empty_next = false
+          rule.catch(s).should_not be_valid
+          s.issues.size.should eq 1
+          s.issues.first.location.to_s.should eq ":2:3"
+        end
+      end
+    end
   end
 end

src/ameba/rule/style/redundant_next.cr

@@ -46,15 +46,61 @@ module Ameba::Rule::Style
   # end
   # ```
   #
+  # ### Configuration params
+  #
+  # 1. *allow_multi_next*, default: true
+  #
+  # Allows end-user to configure whether to report or not the next statements
+  # which yield tuple literals i.e.
+  #
+  # ```
+  # block do
+  #   next a, b
+  # end
+  # ```
+  #
+  # If this param equals to `false`, the block above will be forced to be written as:
+  #
+  # ```
+  # block do
+  #   {a, b}
+  # end
+  # ```
+  #
+  # 2. *allow_empty_next*, default: true
+  #
+  # Allows end-user to configure whether to report or not the next statements
+  # without arguments. Sometimes such statements are used to yild the `nil` value explicitly.
+  #
+  # ```
+  # block do
+  #   @foo = :empty
+  #   next
+  # end
+  # ```
+  #
+  # If this param equals to `false`, the block above will be forced to be written as:
+  #
+  # ```
+  # block do
+  #   @foo = :empty
+  #   nil
+  # end
+  # ```
+  #
   # ### YAML config example
   #
   # ```
   # Style/RedundantNext:
   #   Enabled: true
+  #   AllowMultiNext: true
+  #   AllowEmptyNext: true
   # ```
   struct RedundantNext < Base
     properties do
       description "Reports redundant next expressions"
+      allow_multi_next true
+      allow_empty_next true
     end
 
     MSG = "Redundant `next` detected"
@@ -68,6 +114,9 @@ module Ameba::Rule::Style
     end
 
     def test(source, node : Crystal::Next, visitor : AST::RedundantControlExpressionVisitor)
+      return if allow_multi_next && node.exp.is_a?(Crystal::TupleLiteral)
+      return if allow_empty_next && (node.exp.nil? || node.exp.not_nil!.nop?)
+
       source.try &.add_issue self, node, MSG
     end
   end