Delegate static analysis to StaticAnalyzer

by changing StaticAnalyzer to a Temple filter

lib/hamlit/attribute_compiler.rb

@@ -111,8 +111,6 @@ module Hamlit
       type, exp = values.last
 
       case
-      when type == :dynamic && StaticAnalyzer.static?(exp)
-        temple << [:html, :attr, key, [:escape, @escape_attrs, [:static, eval(exp).to_s]]]
       when type == :dynamic && RubyExpression.string_literal?(exp)
         value_temple = [:multi]
         StringInterpolation.compile(exp).each do |type, v|

lib/hamlit/engine.rb

@@ -3,6 +3,7 @@ require 'hamlit/parser'
 require 'hamlit/compiler'
 require 'hamlit/escapable'
 require 'hamlit/html'
+require 'hamlit/static_analyzer'
 
 module Hamlit
   class Engine < Temple::Engine
@@ -21,6 +22,7 @@ module Hamlit
     use Parser
     use Compiler
     use HTML
+    use StaticAnalyzer
     use Escapable
     filter :ControlFlow
     filter :MultiFlattener

lib/hamlit/static_analyzer.rb

@@ -1,7 +1,7 @@
 require 'hamlit/ruby_expression'
 
 module Hamlit
-  class StaticAnalyzer
+  class StaticAnalyzer < Temple::Filter
     STATIC_TOKENS = %i[
       on_tstring_beg on_tstring_end on_tstring_content
       on_embexpr_beg on_embexpr_end
@@ -25,11 +25,11 @@ module Hamlit
       =>
     ].freeze
 
-    def self.static?(exp)
-      return false if exp.nil? || exp.strip.empty?
-      return false if RubyExpression.syntax_error?(exp)
+    def self.static?(code)
+      return false if code.nil? || code.strip.empty?
+      return false if RubyExpression.syntax_error?(code)
 
-      Ripper.lex(exp).each do |(_, col), token, str|
+      Ripper.lex(code).each do |(_, col), token, str|
         case token
         when *STATIC_TOKENS
           # noop
@@ -45,5 +45,13 @@ module Hamlit
       end
       true
     end
+
+    def on_dynamic(code)
+      if StaticAnalyzer.static?(code)
+        [:static, eval(code).to_s]
+      else
+        [:dynamic, code]
+      end
+    end
   end
 end

test/hamlit/optimization_test.rb

@@ -0,0 +1,12 @@
+describe 'optimization' do
+  def compiled_code(haml)
+    Hamlit::Engine.new.call(haml)
+  end
+
+  describe 'static analysis' do
+    it 'renders static value for href statically' do
+      haml = %|%a{ href: 1 }|
+      assert_equal true, compiled_code(haml).include?(%|href='1'|)
+    end
+  end
+end