Chore/#71 refactor tests using msw (#107)

* test(backstage-plugin): Add msw and refactor tests

Add msw to mock backend and avoid mocking the service.
Simplify some test cases by checking for only the needed elements.
Add error handling to the data service.

Addresses #71

* test(backstage-plugin): Add data service tests

Use msw to add group data service tests and remove the ignore comment.a

Addresses #71

* test(backstage-plugin): Fix linting test files

Move test setup files out of source folder to avoid needing dependencies instead of dev dependencies
when compiling typescript.

Addresses #71

* test(backstage-plugin): Downgrade msw

Downgrade msw to be inline with backstage setup and make it work with the tsconfig.

Addresses #71

* test(backstage-plugin): Add consts for urls

Add reusable consts for testing urls to mock with msw and supply in mock config

Addresses #71

* test(backstage-plugin): Change value used in tests

So that we can check for the exact decimal used from the response.
Should help make the test a bit clearer.

Addresses #71

backstage-plugin/plugins/open-dora/package.json

@@ -49,7 +49,8 @@
     "@testing-library/user-event": "^14.0.0",
     "@types/node": "*",
     "cross-fetch": "^3.1.5",
-    "msw": "^1.0.0"
+    "msw": "^1.3.2",
+    "undici": "^5.27.2"
   },
   "files": [
     "dist",
@@ -64,6 +65,14 @@
         "lines": 100,
         "statements": 100
       }
-    }
+    },
+    "testEnvironmentOptions": {
+      "customExportConditions": [
+        ""
+      ]
+    },
+    "setupFiles": [
+      "../testing/jest.polyfills.js"
+    ]
   }
 }