Add basic code breaking for variable assignments

Author: paulgoetze

code_breaker.gemspec

@@ -27,7 +27,10 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
+  spec.add_dependency "parser", "~> 2.2"
+  spec.add_dependency "activesupport", "~> 4"
+
   spec.add_development_dependency "bundler", "~> 1.10"
   spec.add_development_dependency "rake", "~> 10.0"
-  spec.add_development_dependency "rspec"
+  spec.add_development_dependency "rspec", " ~> 3.2"
 end

lib/code_breaker.rb

@@ -1,5 +1,9 @@
 require "code_breaker/version"
+require "code_breaker/parser"
 
 module CodeBreaker
-  # Your code goes here...
+
+  def self.parse(code)
+    CodeBreaker::Parser.new(code).run
+  end
 end

lib/code_breaker/parser.rb

@@ -0,0 +1,44 @@
+require 'parser/current'
+require 'active_support/inflector'
+
+module CodeBreaker
+  class Parser
+
+    attr_reader :input, :output
+
+    def initialize(code)
+      @input = code.to_s.strip
+    end
+
+    def run
+      parsed = ::Parser::CurrentRuby.parse(@input)
+      nodes = parsed.loc.node.children
+      children = nodes[1].children
+
+      result = parse(children)
+      @output = cleanup(result)
+    end
+
+    private
+
+    def parse(nodes)
+      nodes.map do |node|
+        node.respond_to?(:children) ? parse(node.children).to_a : node
+      end
+    end
+
+    def cleanup(nodes)
+      result = nodes.map do |node|
+        if node.kind_of?(Symbol)
+          node
+        elsif node.kind_of?(Array) && node.length == 1
+          node[0].class
+        elsif node.kind_of?(Array)
+          node[0].nil? ? node[1].to_s.constantize : cleanup(node)
+        end
+      end
+
+      result.flatten
+    end
+  end
+end

spec/code_breaker_spec.rb

@@ -5,7 +5,13 @@
     expect(CodeBreaker::VERSION).not_to be nil
   end
 
-  it 'does something useful' do
-    expect(false).to eq(true)
+  describe '::parse' do
+    it 'instanciates a new Parser and runs it' do
+      allow_any_instance_of(CodeBreaker::Parser).to receive(:run) { 'parsed' }
+      expect_any_instance_of(CodeBreaker::Parser).to receive(:run)
+
+      result = CodeBreaker.parse('gem_name = "code_breaker"')
+      expect(result).to eq 'parsed'
+    end
   end
 end

spec/parser_spec.rb

@@ -0,0 +1,27 @@
+require 'spec_helper'
+
+describe CodeBreaker::Parser do
+
+  let(:code_snippet) { 'gem_name = "code_breaker"' }
+  subject { CodeBreaker::Parser.new(code_snippet) }
+
+  it { is_expected.to respond_to :run }
+  it { is_expected.to respond_to :input }
+  it { is_expected.to respond_to :output }
+
+  describe '#run' do
+    it 'returns an Array' do
+      expect(subject.run).to be_an Array
+    end
+
+    context 'for code snippets defining a variable' do
+      it 'returns the called classes and methods of the right hand side' do
+        code_snippet = 'number = 1 + 2.3 - Rational(2,3) * Complex(0.4, 0.2)'
+        expected_result = [Fixnum, :+, Float, :-, Rational, :*, Complex]
+        actual_result = CodeBreaker::Parser.new(code_snippet).run
+
+        expect(actual_result).to eq expected_result
+      end
+    end
+  end
+end