[load_from_json] changelog updates, readme updates, code style fixes

CHANGELOG.md

@@ -2,7 +2,11 @@
 All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
-## Changed
+### Added
+- `load_from_json`- a command that provides an ability to define config settings
+  by loading them from a json file (in `load_from_yaml` manner);
+
+### Changed
 - Support for Ruby 2.2 has ended;
 
 ## [0.4.0] - 2018-06-24

README.md

@@ -31,6 +31,7 @@ require 'qonfig'
 - [State freeze](#state-freeze)
 - [Settings as Predicates](#settings-as-predicates)
 - [Load from YAML file](#load-from-yaml-file)
+- [Load from JSON file](#load-from-json-file)
 - [Load from ENV](#load-from-env)
 - [Load from \_\_END\_\_](#load-from-__end__) (aka `load_from_self`)
 - [Smart Mixin](#smart-mixin) (`Qonfig::Configurable`)
@@ -482,6 +483,65 @@ Config.new.to_h # => { "nonexistent_yaml" => {}, "another_key" => nil }
 
 ---
 
+### Load from JSON file
+
+- `:strict` mode (fail behaviour when the required yaml file doesnt exist):
+  - `true` (by default) - causes `Qonfig::FileNotFoundError`;
+  - `false` - do nothing, ignore current command;
+
+```json
+<!-- options.json -->
+{
+  "user": "0exp",
+  "password": 12345,
+  "rubySettings": {
+    "allowedVersions": ["2.3", "2.4.2", "1.9.8"],
+    "gitLink": null,
+    "withAdditionals": false
+  }
+}
+```
+
+```ruby
+class Config < Qonfig::DataSet
+  load_from_json 'options.json'
+end
+
+config = Config.new
+
+config.settings.user # => '0exp'
+config.settings.password # => 12345
+config.settings.rubySettings.allowedVersions # => ['2.3', '2.4.2', '1.9.8']
+config.settings.rubySettings.gitLink # => nil
+config.settings.rubySettings.withAdditionals # => false
+```
+
+```ruby
+# --- strict mode ---
+class Config < Qonfig::DataSet
+  setting :nonexistent_json do
+    load_from_yaml 'nonexistent_json.json', strict: true # true by default
+  end
+
+  setting :another_key
+end
+
+Config.new # => Qonfig::FileNotFoundError
+
+# --- non-strict mode ---
+class Config < Qonfig::DataSet
+  settings :nonexistent_json do
+    load_from_yaml 'nonexistent_json.json', strict: false
+  end
+
+  setting :another_key
+end
+
+Config.new.to_h # => { "nonexistent_json" => {}, "another_key" => nil }
+```
+
+---
+
 ### Load from ENV
 
 - `:convert_values` (`false` by default):

spec/features/load_from_json_spec.rb

@@ -71,7 +71,7 @@ class NonFailingJSONConfig < Qonfig::DataSet
         end
 
         expect { NonFailingJSONConfig.new }.not_to raise_error
-        expect(NonFailingJSONConfig.new.to_h).to eq({ 'nested' => {} })
+        expect(NonFailingJSONConfig.new.to_h).to eq('nested' => {})
       end
     end
   end

spec/features/load_from_yaml_spec.rb

@@ -97,7 +97,7 @@ class NonFailingYAMLConfig < Qonfig::DataSet
         end
 
         expect { NonFailingYAMLConfig.new }.not_to raise_error
-        expect(NonFailingYAMLConfig.new.to_h).to eq({ 'nested' => {} })
+        expect(NonFailingYAMLConfig.new.to_h).to eq('nested' => {})
       end
     end
   end