[next] Jest implementation for React Components (#1733)

* Make jest testing work with custom path and css modules

* Add first test

* feat: added unit tests to ci

* fix: updated package-lock.json

* Update cssTransform.js

* Update cssTransform.js

* Fix test in ci

src/core/client/stream/components/Comment.spec.tsx

@@ -0,0 +1,28 @@
+import React from "react";
+import { createRenderer } from "react-test-renderer/shallow";
+import Comment from "./Comment";
+
+it("renders username and body", () => {
+  const props = {
+    author: {
+      username: "Marvin",
+    },
+    body: "Woof",
+  };
+  const renderer = createRenderer();
+  renderer.render(<Comment {...props} />);
+  expect(renderer.getRenderOutput()).toMatchSnapshot();
+});
+
+it("renders with gutterBottom", () => {
+  const props = {
+    author: {
+      username: "Marvin",
+    },
+    body: "Woof",
+    gutterBottom: true,
+  };
+  const renderer = createRenderer();
+  renderer.render(<Comment {...props} />);
+  expect(renderer.getRenderOutput()).toMatchSnapshot();
+});

src/core/client/stream/components/__snapshots__/Comment.spec.tsx.snap

@@ -0,0 +1,33 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`renders username and body 1`] = `
+<div
+  className="root"
+>
+  <withPropsOnChange(Typography)
+    className="author"
+    gutterBottom={true}
+  >
+    Marvin
+  </withPropsOnChange(Typography)>
+  <withPropsOnChange(Typography)>
+    Woof
+  </withPropsOnChange(Typography)>
+</div>
+`;
+
+exports[`renders with gutterBottom 1`] = `
+<div
+  className="root gutterBottom"
+>
+  <withPropsOnChange(Typography)
+    className="author"
+    gutterBottom={true}
+  >
+    Marvin
+  </withPropsOnChange(Typography)>
+  <withPropsOnChange(Typography)>
+    Woof
+  </withPropsOnChange(Typography)>
+</div>
+`;