allow credentials to provide the code

app/models/agents/java_script_agent.rb

@@ -21,11 +21,15 @@ class JavaScriptAgent < Agent
       * `this.options(key)`
       * `this.log(message)`
       * `this.error(message)`
-
     MD
 
     def validate_options
-      errors.add(:base, "The 'code' option is required") unless options['code'].present?
+      cred_name = credential_referenced_by_code
+      if cred_name
+        errors.add(:base, "The credential '#{cred_name}' referenced by code cannot be found") unless credential(cred_name).present?
+      else
+        errors.add(:base, "The 'code' option is required") unless options['code'].present?
+      end
     end
 
     def working?
@@ -99,10 +103,23 @@ def execute_js(js_function, incoming_events = [])
         end
       end
 
-      context.eval(options['code'])
+      context.eval(code)
       context.eval("Agent.#{js_function}();")
     end
 
+    def code
+      cred = credential_referenced_by_code
+      if cred
+        credential(cred) || 'Agent.check = function() { this.error("Unable to find credential"); };'
+      else
+        options['code']
+      end
+    end
+
+    def credential_referenced_by_code
+      options['code'] =~ /\Acredential:(.*)\Z/ && $1
+    end
+
     def setup_javascript
       <<-JS
         function Agent() {};

spec/models/agents/java_script_agent_spec.rb

@@ -22,6 +22,14 @@
       @agent.options.delete('code')
       @agent.should_not be_valid
     end
+
+    it "accepts a credential, but it must exist" do
+      @agent.should be_valid
+      @agent.options['code'] = 'credential:foo'
+      @agent.should_not be_valid
+      users(:jane).user_credentials.create! :credential_name => "foo", :credential_value => "bar"
+      @agent.reload.should be_valid
+    end
   end
 
   describe "#working?" do
@@ -55,7 +63,7 @@
   describe "executing code" do
     it "works by default" do
       @agent.options = @agent.default_options
-      @agent.options['make_event'] = true;
+      @agent.options['make_event'] = true
       @agent.save!
 
       lambda {
@@ -66,6 +74,26 @@
       }.should change { Event.count }.by(2)
     end
 
+
+    describe "using credentials as code" do
+      before do
+        @agent.user.user_credentials.create :credential_name => 'code-foo', :credential_value => 'Agent.check = function() { this.log("ran it"); };'
+        @agent.options['code'] = 'credential:code-foo'
+        @agent.save!
+      end
+
+      it "accepts credentials" do
+        @agent.check
+        AgentLog.last.message.should == "ran it"
+      end
+
+      it "logs an error when the credential goes away" do
+        @agent.user.user_credentials.delete_all
+        @agent.reload.check
+        AgentLog.last.message.should == "Unable to find credential"
+      end
+    end
+
     describe "error handling" do
       it "should log an error when V8 has issues" do
         @agent.options['code'] = 'syntax error!'