added response data sorting middleware

middleware/sortResponseData.js

@@ -0,0 +1,19 @@
+const _ = require('lodash');
+
+function setup(comparator) {
+  function middleware(req, res, next) {
+    // do nothing if there's nothing to do
+    if (_.isEmpty(_.get(res, 'data', []))) {
+      return next();
+    }
+
+    res.data = res.data.sort(comparator);
+
+    next();
+  }
+
+  return middleware;
+
+}
+
+module.exports = setup;

test/unit/middleware/sortResponseData.js

@@ -0,0 +1,88 @@
+const sortResponseData = require('../../../middleware/sortResponseData');
+
+module.exports.tests = {};
+
+module.exports.tests.doIt = (test, common) => {
+  test('undefined res should return without interacting with comparator', (t) => {
+    const comparator = () => {
+      throw Error('should not have been called');
+    };
+
+    const sort = sortResponseData(comparator);
+
+    sort(undefined, undefined, () => {
+      t.end();
+    });
+
+  });
+
+  test('undefined res.data should return without interacting with comparator', (t) => {
+    const comparator = () => {
+      throw Error('should not have been called');
+    };
+
+    const sort = sortResponseData(comparator);
+
+    const res = {};
+
+    sort(undefined, res, () => {
+      t.deepEquals(res, {});
+      t.end();
+    });
+
+  });
+
+  test('empty res.data should not cause problems', (t) => {
+    const comparator = () => {
+      throw Error('should not have been called');
+    };
+
+    const sort = sortResponseData(comparator);
+
+    const res = {
+      data: []
+    };
+
+    sort(undefined, res, () => {
+      t.deepEquals(res.data, [], 'res.data should still be empty');
+      t.end();
+    });
+
+  });
+
+  test('comparator should be consulted for sorting res.data when defined', (t) => {
+    const comparator = (a, b) => {
+      return a.key > b.key;
+    };
+
+    const sort = sortResponseData(comparator);
+
+    const res = {
+      data: [
+        { key: 3 },
+        { key: 2 },
+        { key: 1 },
+      ]
+    };
+
+    sort(undefined, res, () => {
+      t.deepEquals(res.data.shift(), { key: 1 });
+      t.deepEquals(res.data.shift(), { key: 2 });
+      t.deepEquals(res.data.shift(), { key: 3 });
+      t.end();
+    });
+
+  });
+
+};
+
+module.exports.all = (tape, common) => {
+
+  function test(name, testFunction) {
+    return tape(`[middleware] sortResponseData: ${name}`, testFunction);
+  }
+
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};

test/unit/run.js

@@ -40,6 +40,7 @@ var tests = [
   require('./middleware/parseBBox'),
   require('./middleware/sendJSON'),
   require('./middleware/normalizeParentIds'),
+  require('./middleware/sortResponseData'),
   require('./middleware/trimByGranularity'),
   require('./middleware/trimByGranularityStructured'),
   require('./middleware/requestLanguage'),