Support arbitrary sources in Config.load_files and Config.load_and_set_settings (#315)

* Add instructions for running specs

* Backfile test for Pathname support in load_files

There's a .to_s call in there that's likely to support these kinds of
objects, but there wasn't a test for it.

* Rename `file` variables to `source`

In an upcoming change, we'll allow arbirtary sources as parameters to
these methods, instead of just filenames. The method names remain
unchanged for now for backwards compatibility.

* Support arbitrary Source objects in Config.load_files

* Add test for loading HashSource from load_files

* Remove uniq call in load_files

This uniq call causes issues when mixing the types of sources. This
change can technically break some applications that were depending on
the de-deduplication of source files.

* Remove .to_s call in load_files on source

This change effectively conslidates the logic for coercing source
specifications to Source objects into `Config::Options#add_source!`.
For sources specified as Strings or Pathnames, there is effectively no
change, but for sources specified as something else that responds to
`.to_s`, this change could be breaking. In those cases, application
developers can explicitly call `.to_s` on those objects before handing
them to config.

* Add CHANGELOG entry

Author: cjlarose

CHANGELOG.md

@@ -2,7 +2,11 @@
 
 ## Unreleased
 
-...
+### BREAKING CHANGES
+
+* Support `HashSource` and `EnvSource` instances in `Config.load_files` and `Config.load_and_set_settings`. ([#315](https://github.com/rubyconfig/config/pull/315)). There are a few subtle breaking changes:
+  * Previously, `Config.load_files` (called from `Config.load_and_set_settings`) would call `.to_s` on each of its arguments. Now, this responsibility is defered to YAMLSource. In effect, if your application passes String or Pathname objects to `Config.load_files`, no changes are necessary, but if you were somehow relying on the `.to_s` call for some other type of object, you'll now need to call `.to_s` on that object before passing it to `Config`.
+  * Before this change, `Config.load_files` would call `uniq` on its argument array. This call has been removed, so duplicate file paths are not removed before further processing. In some cases, this can cause differences in behavior since later config files override the values in earlier ones. In most cases, it's best to ensure that duplicate paths are not passed to `Config.load_files`.
 
 ## 3.1.1
 

README.md

@@ -533,6 +533,33 @@ You are very warmly welcome to help. Please follow our [contribution guidelines]
 
 Any and all contributions offered in any form, past present or future are understood to be in complete agreement and acceptance with [MIT](LICENSE) license.
 
+### Running specs
+
+Setup
+
+```sh
+bundle install
+bundle exec appraisal install
+```
+
+List defined appraisals:
+
+```sh
+bundle exec appraisal list
+```
+
+Run specs for specific appraisal:
+
+```sh
+bundle exec appraisal rails-6.1 rspec
+```
+
+Run specs for all appraisals:
+
+```sh
+bundle exec appraisal rspec
+```
+
 ## Authors
 
 * [Piotr Kuczynski](http://github.com/pkuczynski)

lib/config.rb

@@ -35,12 +35,12 @@ def self.setup
 
   # Create a populated Options instance from a settings file. If a second file is given, then the sections of that
   # file will overwrite existing sections of the first file.
-  def self.load_files(*files)
+  def self.load_files(*sources)
     config = Options.new
 
     # add settings sources
-    [files].flatten.compact.uniq.each do |file|
-      config.add_source!(file.to_s)
+    [sources].flatten.compact.each do |source|
+      config.add_source!(source)
     end
 
     config.add_source!(Sources::EnvSource.new(ENV)) if Config.use_env
@@ -50,10 +50,10 @@ def self.load_files(*files)
   end
 
   # Loads and sets the settings constant!
-  def self.load_and_set_settings(*files)
+  def self.load_and_set_settings(*sources)
     name = Config.const_name
     Object.send(:remove_const, name) if Object.const_defined?(name)
-    Object.const_set(name, Config.load_files(files))
+    Object.const_set(name, Config.load_files(sources))
   end
 
   def self.setting_files(config_root, env)

lib/config/options.rb

@@ -16,15 +16,15 @@ def empty?
 
     def add_source!(source)
       # handle yaml file paths
-      source = (Sources::YAMLSource.new(source)) if source.is_a?(String)
+      source = (Sources::YAMLSource.new(source)) if source.is_a?(String) || source.is_a?(Pathname)
       source = (Sources::HashSource.new(source)) if source.is_a?(Hash)
 
       @config_sources ||= []
       @config_sources << source
     end
 
     def prepend_source!(source)
-      source = (Sources::YAMLSource.new(source)) if source.is_a?(String)
+      source = (Sources::YAMLSource.new(source)) if source.is_a?(String) || source.is_a?(Pathname)
       source = (Sources::HashSource.new(source)) if source.is_a?(Hash)
 
       @config_sources ||= []

spec/config_spec.rb

@@ -45,6 +45,35 @@
     expect(config.another).to eq("something")
   end
 
+  it 'should load config files specified as Pathname objects' do
+    path = Pathname.new(fixture_path).join('settings.yml')
+    config = Config.load_files(path)
+    expect(config.server).to eq('google.com')
+  end
+
+  it 'should load config files specified as objects responding to :load' do
+    source = double 'source'
+    allow(source).to receive(:load) do
+      { 'server' => 'google.com' }
+    end
+    config = Config.load_files(source)
+    expect(config.server).to eq('google.com')
+  end
+
+  it 'should load config from HashSource' do
+    source = Config::Sources::HashSource.new({ 'server' => 'google.com' })
+    config = Config.load_files(source)
+    expect(config.server).to eq('google.com')
+  end
+
+  it 'should load config from files and HashSource' do
+    file_source = "#{fixture_path}/settings.yml"
+    hash_source = Config::Sources::HashSource.new({ 'size' => 12 })
+    config = Config.load_files(file_source, hash_source)
+    expect(config.server).to eq('google.com')
+    expect(config.size).to eq(12)
+  end
+
   it "should load empty config for a missing file path" do
     config = Config.load_files("#{fixture_path}/some_file_that_doesnt_exist.yml")
     expect(config).to be_empty