Add support for JSON config files

lib/conifer.rb

@@ -10,8 +10,8 @@ def self.included(base)
 
   # rubocop:disable Metrics/ParameterLists
   module ClassMethods
-    def conifer(name, prefix: nil, dir: nil, method: ::File.basename(name.to_s, '.yml'), singleton: false,
-                allowed_classes: [])
+    def conifer(name, prefix: nil, dir: nil, format: :yml, method: ::File.basename(name.to_s, ".#{format}"),
+                singleton: false, allowed_classes: [])
       dir ||= ::File.expand_path(::File.dirname(caller_locations.first.path))
 
       body = proc do

lib/conifer/file.rb

@@ -6,13 +6,15 @@
 module Conifer
   class File
     NotFoundError = Class.new(StandardError)
+    UnsupportedFormatError = Class.new(StandardError)
 
-    attr_reader :name, :prefix, :dir, :allowed_classes
+    attr_reader :name, :dir, :prefix, :format, :allowed_classes
 
-    def initialize(name, dir:, prefix: nil, allowed_classes: [])
+    def initialize(name, dir:, prefix: nil, format: :yml, allowed_classes: [])
       @name = name
-      @prefix = prefix
       @dir = dir
+      @prefix = prefix
+      @format = format
       @allowed_classes = allowed_classes
     end
 
@@ -22,7 +24,14 @@ def [](key)
     end
 
     def parsed
-      @parsed ||= YAML.safe_load(ERB.new(::File.read(path)).result, allowed_classes)
+      @parsed ||= case format
+                  when :yml, :yaml
+                    YAML.safe_load(ERB.new(::File.read(path)).result, allowed_classes)
+                  when :json
+                    JSON.parse(ERB.new(::File.read(path)).result)
+                  else
+                    raise UnsupportedFormatError, "Format '#{format}' is not supported"
+                  end
     end
 
     def path
@@ -36,7 +45,7 @@ def exists?
     end
 
     def filename
-      "#{::File.basename(name.to_s, '.yml')}.yml"
+      "#{::File.basename(name.to_s, ".#{format}")}.#{format}"
     end
 
     def validate!

spec/conifer/file_spec.rb

@@ -4,10 +4,13 @@
 require 'conifer/file'
 
 RSpec.describe Conifer::File do
-  subject(:file) { described_class.new(name, dir: dir, prefix: prefix, allowed_classes: allowed_classes) }
+  subject(:file) do
+    described_class.new(name, dir: dir, format: format, prefix: prefix, allowed_classes: allowed_classes)
+  end
 
   let(:name) { :foo }
   let(:dir) { File.expand_path(__dir__) }
+  let(:format) { :yml }
   let(:prefix) { nil }
   let(:allowed_classes) { [] }
 
@@ -87,6 +90,26 @@
       end
     end
 
+    context 'with json format' do
+      let(:format) { :json }
+
+      it 'returns parsed content of file' do
+        ClimateControl.modify AWS_SECRET_KEY: 'secret' do
+          expect(file.parsed).to eq('foo' => 'bar',
+                                    'development' => { 'aws' => { 'secret_key' => 'secret' }, 'log_level' => 'debug' },
+                                    'test' => { 'log_level' => 'fatal' })
+        end
+      end
+    end
+
+    context 'with unsupported format' do
+      let(:format) { :ruby }
+
+      it 'raises error' do
+        expect { file.parsed }.to raise_error Conifer::File::UnsupportedFormatError
+      end
+    end
+
     context 'with non-primitive values' do
       let(:name) { :dates }
 

spec/conifer/foo.json

@@ -0,0 +1,12 @@
+{
+  "foo": "bar",
+  "development": {
+    "aws": {
+      "secret_key": "<%= ENV.fetch('AWS_SECRET_KEY', 12345) %>"
+    },
+    "log_level": "debug"
+  },
+  "test": {
+    "log_level": "fatal"
+  }
+}