From 3d6125473907062567ae33ac00e1ebd60f9a478a Mon Sep 17 00:00:00 2001
From: Sijawusz Pur Rahnama <sija@sija.pl>
Date: Sat, 29 Oct 2022 01:23:26 +0200
Subject: [PATCH 1/3] Populate `Rule::Base+.parsed_doc` on compile time

---
 src/ameba/rule/base.cr | 72 +++++++++++++-----------------------------
 src/read_rule_doc.cr   | 32 +++++++++++++++++++
 2 files changed, 54 insertions(+), 50 deletions(-)
 create mode 100644 src/read_rule_doc.cr

diff --git a/src/ameba/rule/base.cr b/src/ameba/rule/base.cr
index 0ae7016e..5d8ac2cb 100644
--- a/src/ameba/rule/base.cr
+++ b/src/ameba/rule/base.cr
@@ -138,57 +138,29 @@ module Ameba::Rule
       end
     end
 
+    private macro read_rule_doc(filepath = __FILE__)
+      {{ run("../../read_rule_doc",
+           @type.name.split("::").last,
+           filepath
+         ).chomp.stringify }}.presence
+    end
+
     macro inherited
-      protected def self.path_to_source_file
-        __FILE__
-      end
-    end
-
-    # Returns documentation for this rule if any.
-    #
-    # ```
-    # module Ameba
-    #   # This is a test rule.
-    #   # Does nothing.
-    #   class MyRule < Ameba::Rule::Base
-    #     def test(source)
-    #     end
-    #   end
-    # end
-    #
-    # MyRule.parsed_doc # => "This is a test rule.\nDoes nothing."
-    # ```
-    def self.parsed_doc
-      source = File.read(path_to_source_file)
-      nodes = Crystal::Parser.new(source)
-        .tap(&.wants_doc = true)
-        .parse
-      type_name = rule_name.split('/').last?
-
-      DocFinder.new(nodes, type_name).doc
-    end
-
-    # :nodoc:
-    private class DocFinder < Crystal::Visitor
-      getter doc : String?
-      getter type_name : String?
-
-      def initialize(nodes, @type_name)
-        self.accept(nodes)
-      end
-
-      def visit(node : Crystal::ASTNode)
-        return false if @doc
-
-        if node.responds_to?(:name) &&
-           (name = node.name) &&
-           name.is_a?(Crystal::Path) &&
-           name.names.last? == @type_name
-          @doc = node.doc
-        end
-
-        true
-      end
+      # Returns documentation for this rule, if there is any.
+      #
+      # ```
+      # module Ameba
+      #   # This is a test rule.
+      #   # Does nothing.
+      #   class MyRule < Ameba::Rule::Base
+      #     def test(source)
+      #     end
+      #   end
+      # end
+      #
+      # MyRule.parsed_doc # => "This is a test rule.\nDoes nothing."
+      # ```
+      class_getter parsed_doc : String? = read_rule_doc
     end
   end
 
diff --git a/src/read_rule_doc.cr b/src/read_rule_doc.cr
new file mode 100644
index 00000000..d02b12e8
--- /dev/null
+++ b/src/read_rule_doc.cr
@@ -0,0 +1,32 @@
+require "compiler/crystal/syntax/*"
+
+private class DocFinder < Crystal::Visitor
+  getter type_name : String?
+  getter doc : String?
+
+  def initialize(nodes, @type_name)
+    self.accept(nodes)
+  end
+
+  def visit(node : Crystal::ASTNode)
+    return false if @doc
+
+    if node.responds_to?(:name) &&
+       (name = node.name) &&
+       name.is_a?(Crystal::Path) &&
+       name.names.last? == @type_name
+      @doc = node.doc
+    end
+
+    true
+  end
+end
+
+type_name, path_to_source_file = ARGV
+
+source = File.read(path_to_source_file)
+nodes = Crystal::Parser.new(source)
+  .tap(&.wants_doc = true)
+  .parse
+
+puts DocFinder.new(nodes, type_name).doc

From d55b93c866d7ef1fbebda52ec5d11dc0f870a2c0 Mon Sep 17 00:00:00 2001
From: Sijawusz Pur Rahnama <sija@sija.pl>
Date: Sat, 29 Oct 2022 18:03:30 +0200
Subject: [PATCH 2/3] Rename `read_rule_doc` -> `read_type_doc`

Also, move the helper script into the `contrib` directory
---
 src/ameba/rule/base.cr                             | 6 +++---
 src/{read_rule_doc.cr => contrib/read_type_doc.cr} | 0
 2 files changed, 3 insertions(+), 3 deletions(-)
 rename src/{read_rule_doc.cr => contrib/read_type_doc.cr} (100%)

diff --git a/src/ameba/rule/base.cr b/src/ameba/rule/base.cr
index 5d8ac2cb..70ae53d8 100644
--- a/src/ameba/rule/base.cr
+++ b/src/ameba/rule/base.cr
@@ -138,8 +138,8 @@ module Ameba::Rule
       end
     end
 
-    private macro read_rule_doc(filepath = __FILE__)
-      {{ run("../../read_rule_doc",
+    private macro read_type_doc(filepath = __FILE__)
+      {{ run("../../contrib/read_type_doc",
            @type.name.split("::").last,
            filepath
          ).chomp.stringify }}.presence
@@ -160,7 +160,7 @@ module Ameba::Rule
       #
       # MyRule.parsed_doc # => "This is a test rule.\nDoes nothing."
       # ```
-      class_getter parsed_doc : String? = read_rule_doc
+      class_getter parsed_doc : String? = read_type_doc
     end
   end
 
diff --git a/src/read_rule_doc.cr b/src/contrib/read_type_doc.cr
similarity index 100%
rename from src/read_rule_doc.cr
rename to src/contrib/read_type_doc.cr

From ca2c5a727329e984d1122700bf74fb529e091024 Mon Sep 17 00:00:00 2001
From: Sijawusz Pur Rahnama <sija@sija.pl>
Date: Sat, 29 Oct 2022 18:07:52 +0200
Subject: [PATCH 3/3] Small refactor to `DocFinder#visit`

---
 src/contrib/read_type_doc.cr | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/contrib/read_type_doc.cr b/src/contrib/read_type_doc.cr
index d02b12e8..53ec0e2d 100644
--- a/src/contrib/read_type_doc.cr
+++ b/src/contrib/read_type_doc.cr
@@ -1,7 +1,7 @@
 require "compiler/crystal/syntax/*"
 
 private class DocFinder < Crystal::Visitor
-  getter type_name : String?
+  getter type_name : String
   getter doc : String?
 
   def initialize(nodes, @type_name)
@@ -11,11 +11,8 @@ private class DocFinder < Crystal::Visitor
   def visit(node : Crystal::ASTNode)
     return false if @doc
 
-    if node.responds_to?(:name) &&
-       (name = node.name) &&
-       name.is_a?(Crystal::Path) &&
-       name.names.last? == @type_name
-      @doc = node.doc
+    if node.responds_to?(:name) && (name = node.name).is_a?(Crystal::Path)
+      @doc = node.doc if name.names.last? == @type_name
     end
 
     true