feat(@angular-devkit/core): add support for schema in template

Before we were messing with ownKeys to only return defined properties, but that
has the side effect that those will not work inside a "with() {}" clause, which
is what templates are using.

We now need a serialize symbol if we want to only serialize defined properties,
but for now parity with @ngtools/json-schema is not a priority.

packages/angular_devkit/core/src/json/schema/serializers/templates/javascript/prop-object.ejs

@@ -37,9 +37,13 @@ const handlers = Object.create(null);
 }
 %>
 
+const objectFunctions = {
+  hasOwnProperty(name) { return objectProxyHandler.has(null, name); },
+};
+
 
 let defined = false;
-const proxy = new Proxy({}, {
+const objectProxyHandler = {
   isExtensible() { return false; },
   has(target, prop) {
     return (prop in handlers && handlers[prop].isDefined())
@@ -54,6 +58,9 @@ const proxy = new Proxy({}, {
     if (prop in handlers) {
       return handlers[prop].get();
     }
+    if (prop in objectFunctions) {
+      return objectFunctions[prop];
+    }
     return undefined;
   },
   set(target, prop, v) {
@@ -90,15 +97,20 @@ const proxy = new Proxy({}, {
   getOwnPropertyDescriptor(target, prop) {
     if (prop in handlers) {
       return { configurable: true, enumerable: true };
+    } else if (additionalPropertyHandler && prop in additionalPropertyHandler) {
+      return { configurable: true, enumerable: true };
     }
   },
   ownKeys(target) {
     return [].concat(
-      Object.keys(handlers).filter(function(key) { return handlers[key].isDefined(); }),
+      Object.keys(handlers),
       additionalPropertyHandler ? Object.keys(additionalProperties) : []
     );
   },
-});
+};
+
+
+const proxy = new Proxy({}, objectProxyHandler);
 
 const objectHandler = {
   set(v) {

tests/@angular_devkit/core/json/schema/serializers/1.0.javascript_spec.ts

@@ -36,7 +36,7 @@ export function works(registry: schema.JsonSchemaRegistry, schema: any) {
   v.objectKey1.objectKey = { stringKey: 'str2' };
   expect(v.objectKey1.objectKey.stringKey).toBe('str2');
 
-  expect(Object.keys(v.objectKey1)).toEqual(['stringKey', 'objectKey']);
+  expect(Object.keys(v.objectKey1)).toEqual(['stringKey', 'stringKeyDefault', 'objectKey']);
 }
 
 
@@ -55,9 +55,8 @@ export function accessUndefined(registry: schema.JsonSchemaRegistry, schema: any
   expect(v.objectKey1).not.toBe(undefined);
   expect(v.objectKey1.stringKey).toBe('hello');
   expect(v.objectKey1.numberKey).toBe(undefined);
-  expect(v).toEqual({ 'requiredKey': 1, 'objectKey1': { 'stringKey': 'hello' } });
   v.objectKey1.stringKey = undefined;
-  expect(v).toEqual({ 'requiredKey': 1 });
+  expect(v.objectKey1.stringKey).toBe(undefined);
 
   expect(v.stringKeyDefault).toBe('defaultValue');
   expect(v.objectKey1.stringKeyDefault).toBe('defaultValue2');