feat: set $parent on create and set

Closes #41

lib/base.js

@@ -1,3 +1,5 @@
+import { isArray } from 'min-dash';
+
 /**
  * Moddle base element.
  */
@@ -8,5 +10,21 @@ Base.prototype.get = function(name) {
 };
 
 Base.prototype.set = function(name, value) {
+  const descriptor = this.$model.getPropertyDescriptor(this, name);
+
+  if (descriptor && !descriptor.isReference) {
+    if (isArray(value)) {
+      value.forEach(setParent(this));
+    } else if (value instanceof Base) {
+      setParent(this)(value);
+    }
+  }
+
   this.$model.properties.set(this, name, value);
-};
+};
+
+function setParent(parent) {
+  return function(value) {
+    value.$parent = parent;
+  };
+}

test/spec/properties.js

@@ -288,6 +288,134 @@ describe('properties', function() {
       });
 
 
+      describe('parent', function() {
+
+        describe('create', function() {
+
+          it('should set parent if model element', function() {
+
+            // when
+            var complexNesting = model.create('props:ComplexNesting', {
+              nested: model.create('props:Complex')
+            });
+
+            // then
+            expect(complexNesting.get('nested').$parent).to.equal(complexNesting);
+          });
+
+
+          it('should not set parent if not model element', function() {
+
+            // when
+            var complexNesting = model.create('props:ComplexNesting', {
+              foo: {}
+            });
+
+            // then
+            expect(complexNesting.get('foo').$parent).not.to.exist;
+          });
+
+        });
+
+
+        describe('set', function() {
+
+          describe('one', function() {
+
+            it('should set parent if model element', function() {
+
+              // given
+              var complexNesting = model.create('props:ComplexNesting');
+
+              var nested = model.create('props:Complex');
+
+              // when
+              complexNesting.set('nested', nested);
+
+              // then
+              expect(complexNesting.get('nested')).to.equal(nested);
+              expect(nested.$parent).to.equal(complexNesting);
+            });
+
+
+            it('should not set parent if not model element', function() {
+
+              // given
+              var complexNesting = model.create('props:ComplexNesting');
+
+              // when
+              complexNesting.set('foo', {});
+
+              // then
+              expect(complexNesting.get('foo').$parent).not.to.exist;
+            });
+
+
+            it('should not set parent if model element is reference', function() {
+
+              // given
+              var referencingSingle = model.create('props:ReferencingSingle');
+
+              var referencedComplex = model.create('props:Complex');
+
+              // when
+              referencingSingle.set('referencedComplex', referencedComplex);
+
+              // then
+              expect(referencingSingle.get('referencedComplex')).to.equal(referencedComplex);
+              expect(referencedComplex.$parent).not.to.exist;
+            });
+
+          });
+
+
+          describe('many', function() {
+
+            it('should set parent if model elements', function() {
+
+              // given
+              var containedColllection = model.create('props:ContainedCollection');
+
+              var children = [
+                model.create('props:Complex'),
+                model.create('props:Complex')
+              ];
+
+              // when
+              containedColllection.set('children', children);
+
+              // then
+              expect(containedColllection.get('children')).to.eql(children);
+
+              containedColllection.get('children').forEach(child => {
+                expect(child.$parent).to.equal(containedColllection);
+              });
+            });
+
+
+            it('should not set parent if not model element', function() {
+
+              // given
+              var containedCollection = model.create('props:ContainedCollection');
+
+              // when
+              containedCollection.set('foos', [
+                {},
+                {}
+              ]);
+
+              // then
+              containedCollection.get('foos').forEach(foo => {
+                expect(foo.$parent).not.to.exist;
+              });
+            });
+
+          });
+
+        });
+
+      });
+
       forEach([
         false,
         true,
@@ -315,6 +443,7 @@ describe('properties', function() {
         });
 
       });
+
     });