feat: migrate unit tests to Jest (#6353)

* config(jest): updated setup
* config(jest): update testMatch to include jsx files
* config(jest): add transformIgnorePatterns
* config(jest): update ignore files that do not work in jest yet
* config: add test:unit-jest to test script

* fix(jest): lint with eslint-plugin-jest

* refactor(jest): move unit test directory
* refactor(mocha): restore mocha tests that fail in jest

* docs(jest): update helpful scripts with test:unit-jest

test/unit/components/primitive-model.jsx

@@ -0,0 +1,50 @@
+import React from "react"
+import { shallow } from "enzyme"
+import { fromJS } from "immutable"
+import PrimitiveModel from "components/primitive-model"
+
+describe("<PrimitiveModel/>", function () {
+  describe("Model name", function () {
+    const dummyComponent = () => null
+    const components = {
+      Markdown: dummyComponent,
+      EnumModel: dummyComponent
+    }
+    const props = {
+      getComponent: c => components[c],
+      getConfigs: () => ({
+        showExtensions: false
+      }),
+      name: "Name from props",
+      depth: 1,
+      schema: fromJS({
+        type: "string",
+        title: "Custom model title"
+      })
+    }
+
+    it("renders the schema's title", function () {
+      // When
+      const wrapper = shallow(<PrimitiveModel {...props} />)
+      const modelTitleEl = wrapper.find("span.model-title")
+      expect(modelTitleEl.length).toEqual(1)
+
+      // Then
+      expect(modelTitleEl.text()).toEqual("Custom model title")
+    })
+
+    it("falls back to the passed-in `name` prop for the title", function () {
+      // When
+      props.schema = fromJS({
+        type: "string"
+      })
+      const wrapper = shallow(<PrimitiveModel {...props} />)
+      const modelTitleEl = wrapper.find("span.model-title")
+      expect(modelTitleEl.length).toEqual(1)
+
+      // Then
+      expect(modelTitleEl.text()).toEqual("Name from props")
+    })
+
+  })
+})