Support RUBY_ENGINE/RUBY_PLATFORM != 'opal' directives

adambeynon · adambeynon · commit 91f868e2d56b · 2014-11-28T14:30:11.000Z
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,11 @@
 ## edge (upcoming 0.7)
 
+*   Add support for `RUBY_ENGINE/RUBY_PLATFORM != "opal"` pre-processor directives.
+
+        if RUBY_ENGINE != "opal"
+          # this code never compiles
+        end
+
 *   Fix donating methods defined in modules. This ensures that if a class includes more than one module, then the methods defined on the class respect the order in which the modules are included.
 
 *   Improved support for recursive `Hash` for both `#inspect` and `#hash`.
diff --git a/lib/opal/nodes/if.rb b/lib/opal/nodes/if.rb
@@ -13,13 +13,23 @@ class IfNode < Base
       RUBY_PLATFORM_CHECK = [:call, [:const, :RUBY_PLATFORM],
                               :==, [:arglist, [:str, "opal"]]]
 
+      RUBY_ENGINE_CHECK_NOT = [:call, [:call, [:const, :RUBY_ENGINE], :==,
+                                [:arglist, [:str, "opal"]]], :'!', [:arglist]]
+
+      RUBY_PLATFORM_CHECK_NOT = [:call, [:call, [:const, :RUBY_PLATFORM], :==,
+                                  [:arglist, [:str, "opal"]]], :'!', [:arglist]]
+
       def compile
         truthy, falsy = self.truthy, self.falsy
 
         if skip_check_present?
           falsy = nil
         end
 
+        if skip_check_present_not?
+          truthy = nil
+        end
+
         push "if (", js_truthy(test), ") {"
 
         # skip if-body if no truthy sexp
@@ -51,6 +61,10 @@ def skip_check_present?
         test == RUBY_ENGINE_CHECK or test == RUBY_PLATFORM_CHECK
       end
 
+      def skip_check_present_not?
+        test == RUBY_ENGINE_CHECK_NOT or test == RUBY_PLATFORM_CHECK_NOT
+      end
+
       def truthy
         needs_wrapper? ? compiler.returns(true_body || s(:nil)) : true_body
       end
diff --git a/spec/lib/compiler/pre_processed_conditionals_spec.rb b/spec/lib/compiler/pre_processed_conditionals_spec.rb
@@ -0,0 +1,87 @@
+require 'lib/spec_helper'
+
+describe Opal::Compiler do
+  def expect_compiled(*args)
+    expect(Opal::Compiler.new(*args).compile)
+  end
+
+  describe "pre-processed if conditions" do
+    it "compiles if blocks using RUBY_ENGINE/RUBY_PLATFORM == opal" do
+      expect_compiled(<<-RUBY).to include("should_compile_fine")
+      if RUBY_ENGINE == 'opal'
+        :should_compile_fine
+      end
+      RUBY
+
+      expect_compiled(<<-RUBY).to include("so_should_this")
+      if RUBY_PLATFORM == 'opal'
+        :so_should_this
+      end
+      RUBY
+    end
+
+    it "does not compile if blocks using RUBY_ENGINE/RUBY_PLATFORM != opal" do
+      expect_compiled(<<-RUBY).to_not include('should_not_compile')
+        if RUBY_ENGINE != 'opal'
+          :should_not_compile
+        end
+      RUBY
+
+      expect_compiled(<<-RUBY).to_not include('should_not_compile')
+        if RUBY_PLATFORM != 'opal'
+          :should_not_compile
+        end
+      RUBY
+    end
+
+    it "skips elsif/else parts for CONST == opal" do
+      expect_compiled(<<-RUBY).to_not include("should_be_skipped")
+      if RUBY_PLATFORM == "opal"
+        :ok
+      else
+        :should_be_skipped
+      end
+      RUBY
+
+      result = expect_compiled(<<-RUBY)
+      if RUBY_ENGINE == 'opal'
+        :this_compiles
+      elsif false
+        :this_does_not_compile
+      else
+        :this_neither
+      end
+      RUBY
+
+      result.to_not include("this_does_not_compile", "this_neither")
+    end
+
+    it "generates if-code as normal without check" do
+      expect_compiled(<<-RUBY).to include("should_compile", "and_this")
+      if some_conditional
+        :should_compile
+      else
+        :and_this
+      end
+      RUBY
+    end
+  end
+
+  describe "pre-processed unless conditionals" do
+    it "skips over if using RUBY_ENGINE/RUBY_PLATFORM == 'opal'" do
+      expect_compiled(<<-RUBY).to_not include("should_not_compile")
+      unless RUBY_ENGINE == 'opal'
+        :should_not_compile
+      end
+      RUBY
+    end
+
+    it "generates unless code as normal if no check" do
+      expect_compiled(<<-RUBY).to include("this_should_compile")
+      unless this_is_true
+        :this_should_compile
+      end
+      RUBY
+    end
+  end
+end
diff --git a/spec/lib/compiler_spec.rb b/spec/lib/compiler_spec.rb
@@ -83,73 +83,7 @@
     end
   end
 
-  describe "pre-processed if conditions" do
-    it "compiles if blocks using RUBY_ENGINE/RUBY_PLATFORM == opal" do
-      expect_compiled(<<-RUBY).to include("should_compile_fine")
-        if RUBY_ENGINE == 'opal'
-          :should_compile_fine
-        end
-      RUBY
-
-      expect_compiled(<<-RUBY).to include("so_should_this")
-        if RUBY_PLATFORM == 'opal'
-          :so_should_this
-        end
-      RUBY
-    end
-
-    it "skips elsif/else parts" do
-      expect_compiled(<<-RUBY).to_not include("should_be_skipped")
-        if RUBY_PLATFORM == "opal"
-          :ok
-        else
-          :should_be_skipped
-        end
-      RUBY
-
-      result = expect_compiled(<<-RUBY)
-        if RUBY_ENGINE == 'opal'
-          :this_compiles
-        elsif false
-          :this_does_not_compile
-        else
-          :this_neither
-        end
-      RUBY
-
-      result.to_not include("this_does_not_compile", "this_neither")
-    end
-
-    it "generates if-code as normal without check" do
-      expect_compiled(<<-RUBY).to include("should_compile", "and_this")
-        if some_conditional
-          :should_compile
-        else
-          :and_this
-        end
-      RUBY
-    end
-  end
-
-  describe "pre-processed unless conditionals" do
-    it "skips over if using RUBY_ENGINE/RUBY_PLATFORM == 'opal'" do
-      expect_compiled(<<-RUBY).to_not include("should_not_compile")
-        unless RUBY_ENGINE == 'opal'
-          :should_not_compile
-        end
-      RUBY
-    end
-
-    it "generates unless code as normal if no check" do
-      expect_compiled(<<-RUBY).to include("this_should_compile")
-        unless this_is_true
-          :this_should_compile
-        end
-      RUBY
-    end
-  end
-
-  describe 'pre-processing require-ish methods' do
+    describe 'pre-processing require-ish methods' do
     describe '#require' do
       it 'parses and resolve #require argument' do
         compiler = compiler_for(%Q{require "#{__FILE__}"})
