added predicate for finding results at given layers

controller/predicates/has_results_at_layers.js

@@ -0,0 +1,19 @@
+const _ = require('lodash');
+
+// returns a function that returns true if any result.layer is in any of the
+// supplied layers using array intersection
+
+// example usage: determining if the response contains only admin results
+
+module.exports = (layers) => {
+  return (request, response) => {
+    return !_.isEmpty(
+      _.intersection(
+        // convert layers to an array if it isn't already one
+        _.castArray(layers),
+        // pull all the layer properties into an array
+        _.map(response.data, _.property('layer'))
+    ));
+  };
+
+};

test/unit/controller/predicates/has_results_at_layers.js

@@ -0,0 +1,122 @@
+'use strict';
+
+const _ = require('lodash');
+const has_results_at_layers = require('../../../../controller/predicates/has_results_at_layers');
+
+module.exports.tests = {};
+
+module.exports.tests.interface = (test, common) => {
+  test('valid interface', (t) => {
+    t.equal(typeof has_results_at_layers, 'function', 'has_results_at_layers is a function');
+    t.equal(has_results_at_layers.length, 1);
+    t.end();
+  });
+};
+
+module.exports.tests.true_conditions = (test, common) => {
+  test('should return true when any result.layer matches any layer in array', (t) => {
+    const req = {};
+    const res = {
+      data: [
+        {
+          layer: 'layer 1'
+        },
+        {
+          layer: 'layer 2'
+        },
+        {
+          layer: 'layer 3'
+        }
+      ]
+    };
+
+    t.ok(has_results_at_layers(['layer 2', 'layer 4'])(req, res));
+    t.end();
+
+  });
+
+  test('should return true when any result.layer matches layer string', (t) => {
+    const req = {};
+    const res = {
+      data: [
+        {
+          layer: 'layer 1'
+        },
+        {
+          layer: 'layer 2'
+        },
+        {
+          layer: 'layer 3'
+        }
+      ]
+    };
+
+    t.ok(has_results_at_layers('layer 2')(req, res));
+    t.end();
+
+  });
+
+};
+
+module.exports.tests.false_conditions = (test, common) => {
+  test('should return false when response has undefined data', (t) => {
+    const req = {};
+    const res = {};
+
+    t.notOk(has_results_at_layers('layer')(req, res));
+    t.end();
+
+  });
+
+  test('should return false when response has empty data array', (t) => {
+    const req = {};
+    const res = {
+      data: []
+    };
+
+    t.notOk(has_results_at_layers('layer')(req, res));
+    t.end();
+
+  });
+
+  test('should return false when layer is a substring of non-array string layers parameter', (t) => {
+    const req = {};
+    const res = {
+      data: [
+        {
+          layer: 'aye'
+        }
+      ]
+    };
+
+    t.notOk(has_results_at_layers('layer')(req, res));
+    t.end();
+
+  });
+
+  test('should return false when no results have layer in supplied layers', (t) => {
+    const req = {};
+    const res = {
+      data: [
+        {
+          layer: 'layer 1'
+        }
+      ]
+    };
+
+    t.notOk(has_results_at_layers(['layer 2', 'layer 3'])(req, res));
+    t.end();
+
+  });
+
+};
+
+module.exports.all = (tape, common) => {
+  function test(name, testFunction) {
+    return tape(`GET /has_results_at_layers ${name}`, testFunction);
+  }
+
+  for( const testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};

test/unit/run.js

@@ -17,6 +17,7 @@ var tests = [
   require('./controller/placeholder'),
   require('./controller/search'),
   require('./controller/predicates/has_response_data'),
+  require('./controller/predicates/has_results_at_layers'),
   require('./controller/predicates/has_request_errors'),
   require('./controller/predicates/is_admin_only_analysis'),
   require('./controller/predicates/is_coarse_reverse'),