Changes isStatics to be isIgnorable and overridable.

First step in deprecating statics field as magic ignorable for public API.

shouldupdate.js

@@ -3,7 +3,6 @@
 var filter  = require('lodash.pick'),
     isEqual = require('lodash.isequal');
 
-var isNotIgnorable = not(or(isStatics, isChildren));
 
 /**
  * Directly fetch `shouldComponentUpdate` mixin to use outside of Omniscient.
@@ -57,8 +56,11 @@ function factory (methods) {
       _isEqualState  = methods.isEqualState || isEqualState,
       _isEqualProps  = methods.isEqualProps || isEqualProps,
       _isImmutable   = methods.isImmutable || isImmutable,
+      _isIgnorable   = methods.isIgnorable || isIgnorable,
       _unCursor      = methods.unCursor || unCursor;
 
+  var isNotIgnorable = not(or(_isIgnorable, isChildren));
+
   shouldComponentUpdate.isCursor = _isCursor;
   shouldComponentUpdate.isEqualState = _isEqualState;
   shouldComponentUpdate.isEqualProps = _isEqualProps;
@@ -261,7 +263,21 @@ function not (fn) {
   };
 }
 
-function isStatics (_, key) {
+/**
+ * Predicate to check if a property on props should be ignored or not.
+ * For now this defaults to ignore if property key is `statics`, but that
+ * is deprecated behaviour, and will be removed by the next major release.
+ *
+ * Override through `shouldComponentUpdate.withDefaults`.
+ *
+ * @param {Object} value
+ * @param {String} key
+ *
+ * @module shouldComponentUpdate.isIgnorable
+ * @returns {Boolean}
+ * @api public
+ */
+function isIgnorable (_, key) {
   return key === 'statics';
 }
 

tests/shouldComponentUpdate-test.js

@@ -352,6 +352,23 @@ describe('shouldComponentUpdate', function () {
         done();
       });
 
+      it('should have overridable isIgnorable', function () {
+        var numCalls = 0;
+        var local = shouldComponentUpdate.withDefaults({
+          isIgnorable: function foobar (value, key) {
+            numCalls++;
+            return key === 'ignore';
+          }
+        });
+
+        shouldNotUpdate({
+          cursor: { ignore: 'hello' },
+          nextCursor: { ignore: 'bye' }
+        }, local);
+
+        numCalls.should.be.above(1);
+      });
+
       it('should have debug on product of withDefaults', function () {
         var localComponent = shouldComponentUpdate.withDefaults({
           isCursor: function () { }