Add support for a custom ruby extension directory

README.md

@@ -102,6 +102,8 @@ Possible options:
   to `false`.
 * `ruby_project_path` - the top-level directory of the Ruby gem's project. Defaults to the
   current working directory.
+* `ruby_extension_dir` - the directory relative to `ruby_project_path` where the extension is
+  located. Defaults to `lib`.
 
 ### Example
 

lib/thermite/config.rb

@@ -207,11 +207,19 @@ def cargo_toml_path
       end
     end
 
+    #
+    # The relative directory where the Rust shared library resides, in the context of the Ruby
+    # project.
+    #
+    def ruby_extension_dir
+      @ruby_extension_dir ||= @options.fetch(:ruby_extension_dir, 'lib')
+    end
+
     #
     # Path to the Rust shared library in the context of the Ruby project.
     #
     def ruby_extension_path
-      ruby_path('lib', shared_library)
+      ruby_path(ruby_extension_dir, shared_library)
     end
 
     #

lib/thermite/tasks.rb

@@ -87,6 +87,8 @@ class Tasks < Rake::TaskLib
     #   required. Defaults to `false`.
     # * `ruby_project_path` - the toplevel directory of the Ruby gem's project. Defaults to the
     #   current working directory.
+    # * `ruby_extension_dir` - the directory relative to `ruby_project_path` where the extension is
+    #   located. Defaults to `lib`.
     #
     # These values can be overridden by values with the same key name in the
     # `package.metadata.thermite` section of `Cargo.toml`, if that section exists. The exceptions

test/lib/thermite/config_test.rb

@@ -129,6 +129,13 @@ def test_ruby_extension_path
       assert_equal '/tmp/foobar/lib/libfoo.ext', config.ruby_extension_path
     end
 
+    def test_ruby_extension_path_with_custom_extension_dir
+      FileUtils.stubs(:pwd).returns('/tmp/foobar')
+      config.stubs(:ruby_extension_dir).returns('lib/ext')
+      config.stubs(:shared_library).returns('libfoo.ext')
+      assert_equal '/tmp/foobar/lib/ext/libfoo.ext', config.ruby_extension_path
+    end
+
     def test_default_rust_toplevel_dir
       FileUtils.stubs(:pwd).returns('/tmp/foobar')
       assert_equal '/tmp/foobar', config.rust_toplevel_dir