Add optional and required group parameter sanitizers

sanitiser/_groups.js

@@ -0,0 +1,57 @@
+var _ = require('lodash');
+
+/*
+ * Specify an object and array of keys to check.
+ * An error will be thrown if at least one, but not all of them are specified
+ *
+ * @param {object} - the object
+ * @param {array} - keys to check
+ *
+ * returns true if all are present, false if none are present, throws an exception otherwise
+ */
+function optional_group(object, keys) {
+  var contained_in_object = _.contains.bind(null, Object.keys(object));
+
+  if (keys.every(contained_in_object)) {
+    return true;
+  } else if (!keys.some(contained_in_object)) {
+    return false;
+  } else {
+    throw new Error(error_message(keys));
+  }
+}
+
+/*
+ * Specify an object and array of keys to check.
+ * An error will be thrown if any of the keys are missing from the object
+ */
+function required_group(object, keys) {
+  var contained_in_object = _.contains.bind(null, Object.keys(object));
+
+  if (keys.every(contained_in_object)) {
+    return true;
+  } else {
+    throw new Error(error_message(keys));
+  }
+}
+
+/*
+ * Create a friendly error message from a list of keys
+ */
+function error_message(keys) {
+  var start = 'parameters ';
+
+  var listStart = keys.slice(0, -1).join(', ');
+  var listEnd = ' and ' + keys[keys.length - 1];
+
+  var adjective = (keys.length > 2) ? 'all' : 'both';
+
+  var end = ' must ' + adjective + ' be specified';
+
+  return start + listStart + listEnd + end;
+}
+
+module.exports = {
+  optional: optional_group,
+  required: required_group
+};

test/unit/run.js

@@ -23,6 +23,7 @@ var tests = [
   require('./sanitiser/_flag_bool'),
   require('./sanitiser/_geo_common'),
   require('./sanitiser/_geo_reverse'),
+  require('./sanitiser/_groups'),
   require('./sanitiser/_ids'),
   require('./sanitiser/_layers'),
   require('./sanitiser/_single_scalar_parameters'),

test/unit/sanitiser/_groups.js

@@ -0,0 +1,75 @@
+var groups = require('../../../sanitiser/_groups');
+
+module.exports.tests = {};
+
+module.exports.tests.optional_group = function(test, common) {
+  test('optional group none present ', function(t) {
+    var object = {};
+    t.doesNotThrow(function() {
+      var present = groups.optional(object, [ 'a', 'b' ]);
+      t.equal(present, false, 'group reported not present');
+    });
+    t.end();
+  });
+
+  test('optional group all present ', function(t) {
+    var object = { 'a': 5, 'b': 9 };
+    t.doesNotThrow(function() {
+      var present = groups.optional(object, [ 'a', 'b' ]);
+      t.equal(present, true, 'group reported present');
+    });
+    t.end();
+  });
+
+  test('optional group some present ', function(t) {
+    var object = { 'b': 9 };
+    t.throws(function() {
+      groups.optional(object, [ 'a', 'b' ]);
+    }, new RegExp('parameters a and b must both be specified'));
+    t.end();
+  });
+
+  test('optional group some present (larger group) ', function(t) {
+    var object = { 'b': 9, 'd': 5 };
+    t.throws(function() {
+      groups.optional(object, [ 'a', 'b', 'c', 'd', 'e' ]);
+    }, new RegExp('parameters a, b, c, d and e must all be specified'));
+    t.end();
+  });
+};
+
+module.exports.tests.required_group = function(test, common) {
+  test('required group none present ', function(t) {
+    var object = {};
+    t.throws(function() {
+      groups.required(object, [ 'a', 'b' ]);
+    }, new RegExp('parameters a and b must both be specified'));
+    t.end();
+  });
+
+  test('required group all present ', function(t) {
+    var object = { 'a': 5, 'b': 9 };
+    t.doesNotThrow(function() {
+      groups.required(object, [ 'a', 'b' ]);
+    });
+    t.end();
+  });
+
+  test('required group some present ', function(t) {
+    var object = { 'b': 9 };
+    t.throws(function() {
+      groups.required(object, [ 'a', 'b' ]);
+    }, new RegExp('parameters a and b must both be specified'));
+    t.end();
+  });
+};
+
+module.exports.all = function (tape, common) {
+  function test(name, testFunction) {
+    return tape('SANTIZE _groups ' + name, testFunction);
+  }
+
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};