Support erb in config file

Author: sue445

CONFIG.md

@@ -45,7 +45,7 @@ enum:
 ```
 
 ## Full configuration file
-[config/default.yml](config/default.yml) is used by https://github.com/ruby-go-gem/go-gem-wrapper to generate bindings for Go.
+[config/default.yml.erb](config/default.yml.erb) is used by https://github.com/ruby-go-gem/go-gem-wrapper to generate bindings for Go.
 
 ## `function.include_name`, `struct.include_name`, `type.include_name`, `enum.include_name`
 Return functions and structures that match the condition with a [RubyHeaderParser::Parser](lib/ruby_header_parser/parser.rb)

config/default.yml config/default.yml.erbconfig/default.yml renamed to config/default.yml.erb

@@ -2,6 +2,7 @@
 
 require "yaml"
 require "tmpdir"
+require "erb"
 
 require_relative "ruby_header_parser/version"
 

lib/ruby_header_parser.rb

@@ -11,7 +11,8 @@ class Config
     #
     # @note See [CONFIG.md](../file.CONFIG.html) for config file details
     def initialize(config_file)
-      yaml = File.read(config_file)
+      erb = File.read(config_file)
+      yaml = ERB.new(erb).result
       @data = YAML.safe_load(yaml, aliases: true, permitted_classes: [Regexp])
     end
 

lib/ruby_header_parser/config.rb

@@ -6,14 +6,14 @@
   describe "#function_arg_pointer_hint" do
     subject { config.function_arg_pointer_hint(function_name:, pos:) }
 
-    context "found in config/default.yml" do
+    context "found in config/default.yml.erb" do
       let(:function_name) { "rb_funcallv" }
       let(:pos) { 4 }
 
       it { should eq :array }
     end
 
-    context "not found in config/default.yml" do
+    context "not found in config/default.yml.erb" do
       let(:function_name) { "rb_funcallv" }
       let(:pos) { 5 }
 
@@ -24,13 +24,13 @@
   describe "#function_self_pointer_hint" do
     subject { config.function_self_pointer_hint(function_name) }
 
-    context "found in default.yml" do
+    context "found in default.yml.erb" do
       let(:function_name) { "RSTRING_PTR" }
 
       it { should eq :raw }
     end
 
-    context "not found in config/default.yml" do
+    context "not found in config/default.yml.erb" do
       let(:function_name) { "rb_class2name" }
 
       it { should eq :ref }

spec/ruby_header_parser/config_spec.rb

@@ -29,5 +29,5 @@
 
 # @return [String]
 def default_config_file
-  File.expand_path("../config/default.yml", __dir__)
+  File.expand_path("../config/default.yml.erb", __dir__)
 end