Follow #3778 changes, support to expand doc in macro

spec/compiler/crystal/tools/expand_spec.cr

@@ -7,6 +7,7 @@ private def processed_expand_visitor(code, cursor_location)
   compiler = Compiler.new
   compiler.no_codegen = true
   compiler.no_cleanup = true
+  compiler.wants_doc = true
   result = compiler.compile(Compiler::Source.new(".", code), "fake-no-build")
 
   visitor = ExpandVisitor.new(cursor_location)
@@ -469,4 +470,35 @@ describe "expand" do
 
     assert_expand_fail code, "no expansion found: foo is not macro"
   end
+
+  it "expands macro with doc" do
+    code = <<-CODE
+    macro foo(x)
+      # string of {{ x }}
+      def {{ x }}_str
+        {{ x.stringify }}
+      end
+      # symbol of {{ x }}
+      def {{ x }}_sym
+        :{{ x }}
+      end
+    end
+
+    foo(hello)
+    ‸
+    CODE
+
+    expanded = <<-CODE
+    # string of hello
+    def hello_str
+      "hello"
+    end
+    # symbol of hello
+    def hello_sym
+      :hello
+    end
+    CODE
+
+    assert_expand_result_simple code, "foo(hello)", expanded + "\n"
+  end
 end

src/compiler/crystal/command.cr

@@ -264,8 +264,7 @@ class Crystal::Command
   end
 
   private def create_compiler(command, no_codegen = false, run = false,
-                              hierarchy = false, cursor_command = false,
-                              no_cleanup = false,
+                              hierarchy = false, expand = false, cursor_command = false,
                               single_file = false)
     compiler = Compiler.new
     link_flags = [] of String
@@ -398,7 +397,10 @@ class Crystal::Command
       end
     end
 
-    compiler.no_cleanup = no_cleanup
+    if expand
+      compiler.no_cleanup = true
+      compiler.wants_doc = true
+    end
 
     compiler.link_flags = link_flags.join(" ") unless link_flags.empty?
 

src/compiler/crystal/command/cursor.cr

@@ -18,13 +18,13 @@ class Crystal::Command
   end
 
   private def expand
-    cursor_command("tool expand", no_cleanup: true) do |location, config, result|
+    cursor_command("tool expand", expand: true) do |location, config, result|
       result = ExpandVisitor.new(location).process(result)
     end
   end
 
-  private def cursor_command(command, no_cleanup = false)
-    config, result = compile_no_codegen command, cursor_command: true, no_cleanup: no_cleanup
+  private def cursor_command(command, expand = false)
+    config, result = compile_no_codegen command, cursor_command: true, expand: expand
 
     format = config.output_format
 

src/compiler/crystal/tools/expand.cr

@@ -35,7 +35,7 @@ module Crystal
     end
 
     def self.ast_to_s(node)
-      s = node.to_s
+      s = String.build { |io| node.to_s(io, emit_doc: true) }
       return s unless node.is_a?(MacroIf) || node.is_a?(MacroFor)
       indent = node.location.not_nil!.column_number - 1
       s.lines(chomp: false).map do |line|