feat: Display nullable for object model itself (#5660) (#5868)

test/mocha/components/object-model.jsx

@@ -7,6 +7,7 @@ import ModelExample from "components/model-example"
 import Immutable from "immutable"
 import Model from "components/model"
 import ModelCollapse from "components/model-collapse"
+import Property from "components/property"
 import { inferSchema } from "corePlugins/samples/fn"
 
 describe("<ObjectModel />", function() {
@@ -15,7 +16,8 @@ describe("<ObjectModel />", function() {
       "JumpToPath" : dummyComponent,
       "Markdown" : dummyComponent,
       "Model" : Model,
-      "ModelCollapse" : ModelCollapse
+      "ModelCollapse" : ModelCollapse,
+      "Property" : Property
     }
     const props = {
       getComponent: c => components[c],
@@ -52,6 +54,11 @@ describe("<ObjectModel />", function() {
       },
       className: "for-test"
     }
+    const propsNullable = {
+      ...props,
+      schema: props.schema.set("nullable", true)
+    }
+
     it("renders a collapsible header", function(){
       const wrapper = shallow(<ObjectModel {...props}/>)
       const renderedModelCollapse = wrapper.find(ModelCollapse)
@@ -66,4 +73,18 @@ describe("<ObjectModel />", function() {
         expect(renderedModel.get(1).props.schema.get("name")).toEqual("b")
         expect(renderedModel.get(2).props.schema.get("name")).toEqual("a")
     })
+
+    it("doesn't render `nullable` for model when it absent", function() {
+      const wrapper = shallow(<ObjectModel {...props}/>)
+      const renderProperties = wrapper.find(Property)
+      expect(renderProperties.length).toEqual(0)
+    })
+
+    it("renders `nullable` for model", function() {
+      const wrapper = shallow(<ObjectModel {...propsNullable}/>)
+      const renderProperties = wrapper.find(Property)
+      expect(renderProperties.length).toEqual(1)
+      expect(renderProperties.get(0).props.propKey).toEqual("nullable")
+      expect(renderProperties.get(0).props.propVal).toEqual(true)
+    })
 })