Use custom object formatters for any part of a diff, not just leaf nodes

spec/core/matchers/MismatchTreeSpec.js

@@ -0,0 +1,136 @@
+describe('MismatchTree', function () {
+  describe('#add', function () {
+    describe('When the path is empty', function () {
+      it('flags the root node as mismatched', function () {
+        var tree = new jasmineUnderTest.MismatchTree();
+        tree.add(new jasmineUnderTest.ObjectPath([]));
+        expect(tree.isMismatch).toBe(true);
+      });
+    });
+
+    describe('When the path is not empty', function () {
+      it('flags the node as mismatched', function () {
+        var tree = new jasmineUnderTest.MismatchTree();
+
+        tree.add(new jasmineUnderTest.ObjectPath(['a', 'b']));
+
+        expect(tree.child('a').child('b').isMismatch).toBe(true);
+      });
+
+      it('does not flag ancestors as mismatched', function () {
+        var tree = new jasmineUnderTest.MismatchTree();
+
+        tree.add(new jasmineUnderTest.ObjectPath(['a', 'b']));
+
+        expect(tree.isMismatch).toBe(false);
+        expect(tree.child('a').isMismatch).toBe(false);
+      });
+    });
+
+    it('stores the formatter on only the target node', function () {
+      var tree = new jasmineUnderTest.MismatchTree();
+
+      tree.add(new jasmineUnderTest.ObjectPath(['a', 'b']), formatter);
+
+      expect(tree.formatter).toBeFalsy();
+      expect(tree.child('a').formatter).toBeFalsy();
+      expect(tree.child('a').child('b').formatter).toBe(formatter);
+    });
+
+    it('stores the path to the node', function () {
+      var tree = new jasmineUnderTest.MismatchTree();
+
+      tree.add(new jasmineUnderTest.ObjectPath(['a', 'b']), formatter);
+
+      expect(tree.child('a').child('b').path.components).toEqual(['a', 'b']);
+    });
+  });
+
+  describe('#traverse', function () {
+    it('calls the callback for all nodes that are or contain mismatches', function () {
+      var tree = new jasmineUnderTest.MismatchTree();
+      tree.add(new jasmineUnderTest.ObjectPath(['a', 'b']), formatter);
+      tree.add(new jasmineUnderTest.ObjectPath(['c']));
+      var visit = jasmine.createSpy('visit').and.returnValue(true);
+
+      tree.traverse(visit);
+
+      expect(visit).toHaveBeenCalledWith(
+        new jasmineUnderTest.ObjectPath([]), false, undefined
+      );
+      expect(visit).toHaveBeenCalledWith(
+        new jasmineUnderTest.ObjectPath(['a']), false, undefined
+      );
+      expect(visit).toHaveBeenCalledWith(
+        new jasmineUnderTest.ObjectPath(['a', 'b']), true, formatter
+      );
+      expect(visit).toHaveBeenCalledWith(
+        new jasmineUnderTest.ObjectPath(['c']), true, undefined
+      );
+    });
+
+    it('does not call the callback if there are no mismatches', function () {
+      var tree = new jasmineUnderTest.MismatchTree();
+      var visit = jasmine.createSpy('visit');
+
+      tree.traverse(visit);
+
+      expect(visit).not.toHaveBeenCalled();
+    });
+
+    it('visits parents before children', function () {
+      var tree = new jasmineUnderTest.MismatchTree();
+      tree.add(new jasmineUnderTest.ObjectPath(['a', 'b']));
+      var visited = [];
+
+      tree.traverse(function (path) {
+        visited.push(path);
+        return true;
+      });
+
+      expect(visited).toEqual([
+        new jasmineUnderTest.ObjectPath([]),
+        new jasmineUnderTest.ObjectPath(['a']),
+        new jasmineUnderTest.ObjectPath(['a', 'b'])
+      ]);
+    });
+
+    it('visits children in the order they were recorded', function() {
+      var tree = new jasmineUnderTest.MismatchTree();
+      tree.add(new jasmineUnderTest.ObjectPath(['length']));
+      tree.add(new jasmineUnderTest.ObjectPath([1]));
+      var visited = [];
+
+      tree.traverse(function (path) {
+        visited.push(path);
+        return true;
+      });
+
+      expect(visited).toEqual([
+        new jasmineUnderTest.ObjectPath([]),
+        new jasmineUnderTest.ObjectPath(['length']),
+        new jasmineUnderTest.ObjectPath([1])
+      ]);
+    });
+
+    it('does not visit children if the callback returns falsy', function() {
+      var tree = new jasmineUnderTest.MismatchTree();
+      tree.add(new jasmineUnderTest.ObjectPath(['a', 'b']));
+      var visited = [];
+
+      tree.traverse(function (path) {
+        visited.push(path);
+        return path.depth() === 0;
+      });
+
+      expect(visited).toEqual([
+        new jasmineUnderTest.ObjectPath([]),
+        new jasmineUnderTest.ObjectPath(['a'])
+      ]);
+    });
+  });
+
+  function formatter() {
+  }
+
+});