Vendor bs-react-test-renderer bindings and adapt to our Jest bindings (…

…#737)

package.json

@@ -27,7 +27,8 @@
   "devDependencies": {
     "jest": "^26.0.1",
     "react": "^16.8.1",
-    "react-dom": "^16.8.1"
+    "react-dom": "^16.8.1",
+    "react-test-renderer": "^16.13.1"
   },
   "peerDependencies": {
     "react": "^16.8.1",

src/ReactTestRenderer.re

@@ -0,0 +1,25 @@
+type t;
+
+[@bs.module "react-test-renderer"] [@bs.val] external create :
+  React.element => t = "create";
+
+[@bs.send] external toJSON :
+  t => Js.Json.t = "toJSON";
+
+module Shallow = {
+  type t;
+
+  [@bs.module "react-test-renderer/shallow"] [@bs.val] external createRenderer :
+    unit => t = "createRenderer";
+
+  [@bs.send] external render :
+    t => React.element => option(React.element) = "render";
+
+  [@bs.send] external getRenderOutput :
+    t => option(React.element) = "getRenderOutput";
+
+  [@bs.send] external unmount :
+    t => unit = "unmount";
+
+  let renderWithRenderer = render(createRenderer());
+}

test/ReactTestRenderer__test.re

@@ -0,0 +1,111 @@
+open Jest;
+
+external toObject: ReactTestRenderer.t => Js.t({.}) = "%identity";
+
+module Tester = {
+  [@react.component]
+  let make = () => <div> {React.string("Tester")} </div>;
+};
+
+describe("reactTestRenderer", () => {
+  open Expect;
+
+  test("create returns ReactTestInstance", () => {
+    let component = ReactTestRenderer.create(<Tester />);
+    let keys = Js.Obj.keys(component);
+
+    expect(keys)
+    ->toEqual(
+        arrayContaining([|
+          "_Scheduler",
+          "root",
+          "toJSON",
+          "toTree",
+          "update",
+          "unmount",
+          "unstable_flushSync",
+          "getInstance",
+        |]),
+      );
+  });
+
+  test("toJSON returns test rendered JSON", () => {
+    let component = ReactTestRenderer.create(<Tester />);
+    let json = ReactTestRenderer.toJSON(component);
+    let expected =
+      Js.Json.parseExn(
+        {|
+      {
+        "type": "div",
+        "props": {},
+        "children": [ "Tester" ]
+      }
+    |},
+      );
+    expect(json == expected)->toBe(true);
+  });
+});
+
+let element = <div> {React.string("Tester")} </div>;
+
+describe("reactShallowRenderer", () => {
+  open Expect;
+
+  test("createRenderer", () => {
+    let renderer = ReactTestRenderer.Shallow.createRenderer();
+    let isDefined =
+      renderer
+      |> Js.Undefined.return
+      |> Js.Undefined.toOption
+      |> Option.is_some;
+    expect(isDefined)->toBe(true);
+  });
+
+  test("render accepts renderer", () => {
+    let renderer = ReactTestRenderer.Shallow.createRenderer();
+    let render = ReactTestRenderer.Shallow.render(renderer);
+    expect(Js.typeof(render))->toEqual("function");
+  });
+
+  test("render will render a component", () => {
+    let renderer = ReactTestRenderer.Shallow.createRenderer();
+    let component =
+      ReactTestRenderer.Shallow.render(renderer, <Tester />)
+      ->Option.get;
+    expect(component == element)->toBe(true);
+  });
+
+  test("renderWithRenderer will render a component", () => {
+    let component =
+      ReactTestRenderer.Shallow.renderWithRenderer(<Tester />)
+      ->Option.get;
+
+    expect(component == element)->toBe(true);
+  });
+
+  test("getRenderOutput returns element", () => {
+    let renderer = ReactTestRenderer.Shallow.createRenderer();
+
+    ReactTestRenderer.Shallow.render(renderer, <Tester />) |> ignore;
+
+    let component =
+      ReactTestRenderer.Shallow.getRenderOutput(renderer)
+      ->Option.get;
+
+    expect(component == element)->toBe(true);
+  });
+
+  test("unmount removes the node", () => {
+    let renderer = ReactTestRenderer.Shallow.createRenderer();
+
+    ReactTestRenderer.Shallow.render(renderer, <Tester />) |> ignore;
+    ReactTestRenderer.Shallow.unmount(renderer);
+
+    let component =
+      ReactTestRenderer.Shallow.getRenderOutput(renderer)
+      ->Option.get
+      ->Js.Null.return;
+
+    expect(component)->toEqual(Js.null);
+  });
+});