Dart Unit Test - Always passing

Question

All,

Here is a unit test for checking the size of a collection

main() {
  test("Resource Manager Image Load", () {
    ResourceManager rm = new ResourceManager();
    int WRONG_SIZE = 1000000;

    rm.loadImageManifest("data/rm/test_images.yaml").then((_){
      print("Length="+ rm.images.length.toString()); // PRINTS '6' - WHICH IS CORRECT
      expect(rm.images, hasLength(WRONG_SIZE));
    });
  });
}

I am running this from a browser (client-side Dart libraries are in use) and it ALWAYS passes, no matter what the value of WRONG_SIZE.

Help appreciated.

Answer 1

In such simple cases you can just return the future. The unit test framework recognizes it and waits for the future to complete. This also works for setUp/tearDown.

main() {
  test("Resource Manager Image Load", () {
    ResourceManager rm = new ResourceManager();
    int WRONG_SIZE = 1000000;

    return rm.loadImageManifest("data/rm/test_images.yaml").then((_) {
    //^^^^
      print("Length="+ rm.images.length.toString()); // PRINTS '6' - WHICH IS CORRECT
      expect(rm.images, hasLength(WRONG_SIZE));
    });
  });
}