Add logging helper module

This module has helper methods for logging. Currently it has methods to:

* detect if DNT is enabled
* remove sensitive information from input fields for logging

helper/logging.js

@@ -0,0 +1,24 @@
+var fieldsToRemove = ['text', 'focus.point.lat', 'focus.point.lon',
+  'boundary.circle.lat', 'boundary.circle.lon', 'point.lat', 'point.lon'];
+
+function isDNT(req) {
+  if (!req.headers) {
+    return false;
+  }
+  return req.headers.DNT || req.headers.dnt || req.headers.do_not_track;
+}
+
+function removeFields(query) {
+  fieldsToRemove.forEach(function(field) {
+    if (query[field]) {
+      query[field] = '[removed]';
+    }
+  });
+
+  return query;
+}
+
+module.exports = {
+  isDNT: isDNT,
+  removeFields: removeFields
+};

test/unit/helper/logging.js

@@ -0,0 +1,96 @@
+var logging = require('../../../helper/logging');
+
+module.exports.tests = {};
+
+module.exports.tests.dnt = function(test) {
+  test('DNT=1 triggers DNT detection', function(t) {
+    var req = {
+      headers: {
+        DNT: '1'
+      }
+    };
+
+    t.ok(logging.isDNT(req), 'DNT detected');
+    t.end();
+  });
+
+  test('DNT=0 triggers DNT detection', function(t) {
+    // because this is common apparently, although the spec says to do the opposite
+    // see https://en.wikipedia.org/wiki/Do_Not_Track
+    var req = {
+      headers: {
+        DNT: '0'
+      }
+    };
+
+    t.ok(logging.isDNT(req), 'DNT detected');
+    t.end();
+  });
+
+  test('do_not_track header triggers DNT detection', function(t) {
+    // according to @riordan, some people use this too
+    var req = {
+      headers: {
+        do_not_track: '1'
+      }
+    };
+
+    t.ok(logging.isDNT(req), 'DNT detected');
+    t.end();
+  });
+
+  test('no DNT or do_not_track header does not trigger DNT detection', function(t) {
+    var req = {
+      headers: {
+        'Accept-Charset': 'utf-8'
+      }
+    };
+
+    t.notOk(logging.isDNT(req), 'DNT detected');
+    t.end();
+  });
+};
+
+module.exports.tests.field_removal = function(test) {
+  test('removes multiple fields that may have sensitive information', function(t) {
+    var query = {
+      text: 'possibly sensitive text',
+      'point.lat': 'possibly sensitive location info'
+    };
+
+    var cleaned_query = logging.removeFields(query);
+
+    var expected = {
+      text: '[removed]',
+      'point.lat': '[removed]'
+    };
+
+    t.deepEquals(cleaned_query, expected, 'multiple sensitive fields removed');
+    t.end();
+  });
+
+  test('non-sensitive fields untouched', function(t) {
+    var query = {
+      sources: 'wof,gn'
+    };
+
+    var cleaned_query = logging.removeFields(query);
+
+    var expected = {
+      sources: 'wof,gn'
+    };
+
+    t.deepEquals(cleaned_query, expected, 'non-sensitive fields are not touched');
+    t.end();
+  });
+};
+
+module.exports.all = function (tape, common) {
+  function test(name, testFunction) {
+    return tape('logging: ' + name, testFunction);
+  }
+
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};

test/unit/run.js

@@ -19,6 +19,7 @@ var tests = [
   require('./helper/labelGenerator_GBR'),
   require('./helper/labelGenerator_USA'),
   require('./helper/labelSchema'),
+  require('./helper/logging'),
   require('./helper/type_mapping'),
   require('./helper/sizeCalculator'),
   require('./middleware/confidenceScore'),