remove address/venue/street from requested layers when creating results

refactored for cleanliness and clarity

test/unit/controller/coarse_reverse.js

@@ -533,6 +533,92 @@ module.exports.tests.success_conditions = (test, common) => {
 
   });
 
+  test('no requested layers should use everything', (t) => {
+    // this test is used to test coarse reverse fallback for when non-coarse reverse
+    //  was requested but no non-coarse results were found
+
+    // by plan'ing the number of tests, we can verify that next() was called w/o
+    //  additional bookkeeping
+    t.plan(5);
+
+    const service = (point, do_not_track, callback) => {
+      t.equals(do_not_track, 'do_not_track value');
+      const results = {
+        neighbourhood: [
+          {
+            id: 10,
+            name: 'neighbourhood name',
+            abbr: 'neighbourhood abbr'
+          }
+        ]
+      };
+
+      callback(undefined, results);
+    };
+
+    const logger = require('pelias-mock-logger')();
+
+    const should_execute = () => { return true; };
+    const controller = proxyquire('../../../controller/coarse_reverse', {
+      'pelias-logger': logger,
+      '../helper/logging': {
+        isDNT: () => {
+          return 'do_not_track value';
+        }
+      }
+    })(service, should_execute);
+
+    const req = {
+      clean: {
+        layers: [],
+        point: {
+          lat: 12.121212,
+          lon: 21.212121
+        }
+      }
+    };
+
+    const res = { };
+
+    // verify that next was called
+    const next = () => {
+      t.pass('next() should have been called');
+    };
+
+    controller(req, res, next);
+
+    const expected = {
+      meta: {},
+      data: [
+        {
+          _id: '10',
+          _type: 'neighbourhood',
+          layer: 'neighbourhood',
+          source: 'whosonfirst',
+          source_id: '10',
+          name: {
+            'default': 'neighbourhood name'
+          },
+          phrase: {
+            'default': 'neighbourhood name'
+          },
+          parent: {
+            neighbourhood: ['neighbourhood name'],
+            neighbourhood_id: ['10'],
+            neighbourhood_a: ['neighbourhood abbr']
+          }
+        }
+      ]
+    };
+
+    t.deepEquals(req.clean.layers, [], 'req.clean.layers should be unmodified');
+    t.deepEquals(res, expected);
+    t.notOk(logger.hasErrorMessages());
+
+    t.end();
+
+  });
+
   test('layers specifying only venue, address, or street should not exclude coarse results', (t) => {
     // this test is used to test coarse reverse fallback for when non-coarse reverse
     //  was requested but no non-coarse results were found