[PUI] Added tests for PUI backend stuff (#5864)

* Added tests for PUI backend stuff

* Added coverage for error cases

* Added testing for frontend_settings

* Added more testing for `get_frontend_settings`

InvenTree/web/tests.py

@@ -0,0 +1,68 @@
+"""Tests for PUI backend stuff."""
+import json
+import os
+from pathlib import Path
+from unittest import mock
+
+from InvenTree.config import get_frontend_settings
+from InvenTree.unit_test import InvenTreeTestCase
+
+from .templatetags import spa_helper
+
+
+class TemplateTagTest(InvenTreeTestCase):
+    """Tests for the template tag code."""
+
+    def assertSettings(self, settings_data):
+        """Helper to test if needed args are in the settings."""
+        self.assertTrue('debug' in settings_data)
+        self.assertTrue('server_list' in settings_data)
+        self.assertTrue('show_server_selector' in settings_data)
+        self.assertTrue('environment' in settings_data)
+
+    def test_spa_bundle(self):
+        """Test the 'spa_bundle' template tag"""
+        resp = spa_helper.spa_bundle()
+        self.assertTrue(resp.startswith('<link rel="stylesheet" href="/static/web/assets/index'))
+        shipped_js = resp.split('<script type="module" src="')[1:]
+        self.assertTrue(len(shipped_js) > 0)
+        self.assertTrue(len(shipped_js) == 3)
+
+        manifest_file = Path(__file__).parent.joinpath("static/web/manifest.json")
+        # Try with removed manifest file
+        manifest_file.rename(manifest_file.with_suffix('.json.bak'))  # Rename
+        resp = resp = spa_helper.spa_bundle()
+        self.assertIsNone(resp)
+        manifest_file.with_suffix('.json.bak').rename(manifest_file.with_suffix('.json'))  # Name back
+
+    def test_spa_settings(self):
+        """Test the 'spa_settings' template tag"""
+        resp = spa_helper.spa_settings()
+        self.assertTrue(resp.startswith('<script>window.INVENTREE_SETTINGS='))
+        settings_data_string = resp.replace('<script>window.INVENTREE_SETTINGS=', '').replace('</script>', '')
+        settings_data = json.loads(settings_data_string)
+        self.assertSettings(settings_data)
+
+    def test_get_frontend_settings(self):
+        """Test frontend settings retrieval."""
+        # Normal run for priming
+        rsp = get_frontend_settings()
+        self.assertSettings(rsp)
+
+        # No base_url
+        envs = {'INVENTREE_PUI_URL_BASE': ''}
+        with mock.patch.dict(os.environ, envs):
+            rsp = get_frontend_settings()
+            self.assertSettings(rsp)
+
+        # No debug, no serverlist -> selector
+        rsp = get_frontend_settings(False)
+        self.assertSettings(rsp)
+        self.assertTrue(rsp['show_server_selector'])
+
+        # No debug, serverlist -> no selector
+        envs = {'INVENTREE_PUI_SETTINGS': json.dumps({'server_list': ['aa', 'bb',]})}
+        with mock.patch.dict(os.environ, envs):
+            rsp = get_frontend_settings(False)
+            self.assertFalse('show_server_selector' in rsp)
+            self.assertEqual(rsp['server_list'], ['aa', 'bb',])