Implement writer

lib/rbs/writer.rb

@@ -77,14 +77,19 @@ def write_comment(comment)
     end
 
     def write(contents)
-      dirs = contents.select {|c| c.is_a?(AST::Directives::Base) } #: Array[AST::Directives::t]
+      resolveds = contents.select { _1.is_a?(AST::Directives::Resolved) } #: Array[AST::Directives::Resolved]
+      uses = contents.select {|c| c.is_a?(AST::Directives::Use) } #: Array[AST::Directives::Use]
       decls = contents.select {|c| c.is_a?(AST::Declarations::Base) } #: Array[AST::Declarations::t]
 
-      dirs.each do |dir|
-        write_directive(dir)
+      unless resolveds.empty?
+        puts "# resolved: true"
+        puts
       end
 
-      puts unless dirs.empty?
+      uses.each do |dir|
+        write_use_directive(dir)
+      end
+      puts unless uses.empty?
 
       [nil, *decls].each_cons(2) do |prev, decl|
         raise unless decl
@@ -94,7 +99,7 @@ def write(contents)
       end
     end
 
-    def write_directive(dir)
+    def write_use_directive(dir)
       clauses = dir.clauses.map do |clause|
         case clause
         when AST::Directives::Use::SingleClause

sig/writer.rbs

@@ -96,7 +96,7 @@ module RBS
 
     def format_annotation: (AST::Annotation) -> String
 
-    def write_directive: (AST::Directives::t) -> void
+    def write_use_directive: (AST::Directives::Use) -> void
 
     def write_annotation: (Array[AST::Annotation]) -> void
 

test/rbs/writer_test.rb

@@ -331,4 +331,33 @@ class Foo
 end
     SIG
   end
+
+  def test_magic_comment
+    assert_writer <<-SIG
+# resolved: true
+
+class Foo
+end
+    SIG
+
+    assert_writer <<-SIG
+# resolved: true
+
+use String as S
+
+type s = S
+    SIG
+  end
+
+  def test_magic_comment_error
+    # We don't want the duplicated magic comment...
+
+    assert_fail_assertion do
+      assert_writer <<-SIG
+# resolved: true
+class Foo
+end
+      SIG
+     end
+  end
 end