Implement `has_env' condition keyword

features/tests/has_env.feature

@@ -0,0 +1,32 @@
+@sshd
+Feature: `has_env' condition keyword
+
+  Scenario: succeeds when remote environment variable is defined
+    Given a recipe with:
+      """
+      target 'some_host.test'
+
+      task :testing_env_var_definition do
+        condition { has_env :shell }
+
+        echo 'evaluated'
+      end
+      """
+    When I execute the recipe
+    Then the exit status must be 0
+    And the output must contain "evaluated"
+
+  Scenario: fails when remote environment variable is not defined
+    Given a recipe with:
+      """
+      target 'some_host.test'
+
+      task :testing_env_var_definition do
+        condition { has_env :inexistent_var }
+
+        echo 'evaluated'
+      end
+      """
+    When I execute the recipe
+    Then the exit status must be 0
+    And the output must not contain "evaluated"

lib/producer/core.rb

@@ -5,6 +5,7 @@ require 'producer/core/actions/shell_command'
 
 # condition tests (need to be defined before the condition DSL)
 require 'producer/core/test'
+require 'producer/core/tests/has_env'
 
 require 'producer/core/cli'
 require 'producer/core/condition'

lib/producer/core/condition/dsl.rb

@@ -16,6 +16,8 @@ module Producer
           end
         end
 
+        define_test :has_env, Tests::HasEnv
+
         attr_accessor :tests
 
         def initialize(env, &block)

lib/producer/core/tests/has_env.rb

@@ -0,0 +1,11 @@
+module Producer
+  module Core
+    class Tests
+      class HasEnv < Test
+        def success?
+          env.remote.environment.has_key? arguments.first.to_s.upcase
+        end
+      end
+    end
+  end
+end

spec/producer/core/condition/dsl_spec.rb

@@ -6,6 +6,12 @@ module Producer::Core
     let(:env)     { double('env') }
     subject(:dsl) { Condition::DSL.new(env, &block) }
 
+    %w[has_env].each do |test|
+      it "has `#{test}' test defined" do
+        expect(dsl).to respond_to test.to_sym
+      end
+    end
+
     describe '.evaluate' do
       it 'builds a new DSL sandbox with given env and code' do
         expect(Condition::DSL)

spec/producer/core/tests/has_env_spec.rb

@@ -0,0 +1,41 @@
+require 'spec_helper'
+
+module Producer::Core
+  describe Tests::HasEnv do
+    let(:env)           { Env.new }
+    let(:variable_name) { :some_variable_name }
+    subject(:has_env)   { Tests::HasEnv.new(env, variable_name) }
+
+    it 'is a kind of test' do
+      expect(has_env).to be_a Test
+    end
+
+    describe '#success?' do
+      let(:environment) { double('environment') }
+
+      before do
+        allow(env.remote).to receive(:environment) { environment }
+      end
+
+      it 'stringifies the queried variable name' do
+        expect(environment).to receive(:has_key?).with(kind_of(String))
+        has_env.success?
+      end
+
+      it 'upcases the queried variable name' do
+        expect(environment).to receive(:has_key?).with('SOME_VARIABLE_NAME')
+        has_env.success?
+      end
+
+      it 'returns true when remote environment var is defined' do
+        allow(environment).to receive(:has_key?) { true }
+        expect(has_env.success?).to be true
+      end
+
+      it 'returns false when remote environment var is not defined' do
+        allow(environment).to receive(:has_key?) { false }
+        expect(has_env.success?).to be false
+      end
+    end
+  end
+end