add basic plugin specs for transform registry

spec/plugin-api/hydrogen-provider-spec.js

@@ -0,0 +1,40 @@
+"use babel";
+
+import React from "react";
+
+import { toJS } from "mobx";
+import HydrogenProvider from "./../../lib/plugin-api/hydrogen-provider";
+import Hydrogen from "./../../lib/main";
+import transformManager from "./../../lib/components/transforms";
+import Markdown from "./../../lib/components/transforms/markdown";
+
+describe("Hydrogen Provider", () => {
+  const plugin = Hydrogen.provideHydrogen();
+  it("should create a valid provider", () => {
+    expect(plugin instanceof HydrogenProvider).toBeTruthy();
+  });
+
+  describe("registerTransform", () => {
+    it("should add a new transform", () => {
+      expect(plugin.registerTransform(<Markdown />, "mark")).toBeTruthy();
+      expect(transformManager.transforms.has("mark")).toBeTruthy();
+      expect(transformManager.transforms.get("mark").type).toEqual(Markdown);
+    });
+
+    it("should not override an existing transform", () => {
+      expect(plugin.registerTransform(<Markdown />, "svg")).toBeTruthy();
+      expect(transformManager.transforms.get("svg").type).not.toEqual(Markdown);
+    });
+  });
+
+  describe("unregisterTransform", () => {
+    it("should remove a transform", () => {
+      expect(plugin.unregisterTransform("mark")).toBeTruthy();
+      expect(!transformManager.transforms.has("mark")).toBeTruthy();
+    });
+
+    it("should return false for non-existent key", () => {
+      expect(!plugin.unregisterTransform("mark")).toBeTruthy();
+    });
+  });
+});