add predicate that looks for a parameter in req.clean

controller/predicates/has_request_parameter.js

@@ -0,0 +1,3 @@
+const _ = require('lodash');
+
+module.exports = (parameter) => (req, res) => _.has(req, ['clean', parameter]);

test/unit/controller/predicates/has_request_parameter.js

@@ -0,0 +1,63 @@
+'use strict';
+
+const _ = require('lodash');
+const has_request_parameter = require('../../../../controller/predicates/has_request_parameter');
+
+module.exports.tests = {};
+
+module.exports.tests.interface = (test, common) => {
+  test('valid interface', t => {
+    t.equal(typeof has_request_parameter, 'function', 'has_request_parameter is a function');
+    t.end();
+  });
+};
+
+module.exports.tests.true_conditions = (test, common) => {
+  test('request with specified parameter should return true', t => {
+    [[], {}, 'string value', 17].forEach(val => {
+      const req = {
+        clean: {
+          'parameter name': val
+        }
+      };
+
+      t.ok(has_request_parameter('parameter name')(req));
+
+    });
+
+    t.end();
+
+  });
+
+};
+
+module.exports.tests.false_conditions = (test, common) => {
+  test('request with undefined clean should return false', t => {
+    const req = {};
+
+    t.notOk(has_request_parameter('parameter name')(req));
+    t.end();
+
+  });
+
+  test('request.clean without specified parameter should return false', t => {
+    const req = {
+      clean: {}
+    };
+
+    t.notOk(has_request_parameter('parameter name')(req));
+    t.end();
+
+  });
+
+};
+
+module.exports.all = (tape, common) => {
+  function test(name, testFunction) {
+    return tape(`GET /has_request_parameter ${name}`, testFunction);
+  }
+
+  for( const testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};