housekeeping: reorganize and rewire Mocha tests (#5600)

* move Mocha-run tests to `test/mocha`

* fix relative paths

* fix JSX test paths

* update stagnated JSX tests

* `test/setup.js` -> `test/mocha/setup.js`

* use regex+globstar for test matching

* remove `console.log`

test/mocha/core/plugins/configs/actions.js

@@ -0,0 +1,27 @@
+/* eslint-env mocha */
+import expect, { createSpy } from "expect"
+import { downloadConfig } from "corePlugins/configs/spec-actions"
+
+describe("configs plugin - actions", () => {
+
+  describe("downloadConfig", () => {
+    it("should call the system fetch helper with a provided request", () => {
+      const fetchSpy = createSpy(async () => {}).andCallThrough()
+      const system = {
+        fn: {
+          fetch: fetchSpy
+        }
+      }
+
+      const req = {
+        url: "http://swagger.io/one",
+        requestInterceptor: a => a,
+        responseInterceptor: a => a,
+      }
+
+      downloadConfig(req)(system)
+
+      expect(fetchSpy).toHaveBeenCalledWith(req)
+    })
+  })
+})