test: add unit tests for configuration and download controllers and handle electron app initialization and improve devMode logic

test/unit/config.test.js

@@ -0,0 +1,43 @@
+const {mergeMissingFeatures} = require("../../config");
+
+describe("configuration migration", () => {
+    test("adds missing defaults and preserves user values", () => {
+        const result = mergeMissingFeatures(
+            {enabled: true, retries: 3},
+            {enabled: false}
+        );
+
+        expect(result).toEqual({
+            features: {enabled: false, retries: 3},
+            changed: true,
+        });
+    });
+
+    test("preserves unknown user-defined keys", () => {
+        const result = mergeMissingFeatures(
+            {enabled: true},
+            {enabled: false, customSetting: "keep me"}
+        );
+
+        expect(result).toEqual({
+            features: {enabled: false, customSetting: "keep me"},
+            changed: false,
+        });
+    });
+
+    test("reports no migration when all default keys exist", () => {
+        const result = mergeMissingFeatures(
+            {enabled: true, retries: 3},
+            {enabled: false, retries: 0}
+        );
+
+        expect(result.changed).toBe(false);
+        expect(result.features.retries).toBe(0);
+    });
+
+    test("rejects non-object configurations", () => {
+        expect(() => mergeMissingFeatures({}, [])).toThrow(
+            "User configuration must be a JSON object"
+        );
+    });
+});