Add basic unit tests for Result class

src/util.test.ts

@@ -563,3 +563,28 @@ test("joinAtMost - truncates list if array is > than limit", (t) => {
   t.assert(result.includes("test5"));
   t.false(result.includes("test6"));
 });
+
+test("Result.success creates a success result", (t) => {
+  const result = util.Result.success("test value");
+  t.true(result.isSuccess());
+  t.false(result.isFailure());
+  t.is(result.value, "test value");
+});
+
+test("Result.failure creates a failure result", (t) => {
+  const error = new Error("test error");
+  const result = util.Result.failure(error);
+  t.false(result.isSuccess());
+  t.true(result.isFailure());
+  t.is(result.value, error);
+});
+
+test("Result.orElse returns the value for a success result", (t) => {
+  const result = util.Result.success("success value");
+  t.is(result.orElse("default value"), "success value");
+});
+
+test("Result.orElse returns the default value for a failure result", (t) => {
+  const result = util.Result.failure(new Error("test error"));
+  t.is(result.orElse("default value"), "default value");
+});