FindAll vs Find

[dady8889]

Hello,

I am trying to change the text of multiple inputs at once, and I can't seem to understand how it works.

This test passes:

        [TestMethod]
        public void TestMethod1()
        {
            var cut = RenderComponent<bUnitLightInjectBug.Pages.FetchData>();

            IElement a = cut.Find("#test-a");
            IElement b = cut.Find("#test-b");

            var form = cut.Find("form");

            a.Change("aaaaaaaaaaaaaaaaa");

            Assert.AreEqual(a.GetAttribute("value"), "aaaaaaaaaaaaaaaaa");

            b.Change("bbbbbbbbbbbbbbbbb");

            Assert.AreEqual(b.GetAttribute("value"), "bbbbbbbbbbbbbbbbb");

            form.Submit();
        }

And this does not:

        [TestMethod]
        public void TestMethod2()
        {
            var cut = RenderComponent<bUnitLightInjectBug.Pages.FetchData>();

           // changing false/true does not change anything
            var inputs = cut.FindAll("input", false);
            IElement a = inputs.First(x => x.PreviousElementSibling?.TextContent == "A");
            IElement b = inputs.First(x => x.PreviousElementSibling?.TextContent == "B");

            IElement form = cut.Find("form");

            a.Change("aaaaaaaaaaaaaaaaa");
           // using debug I can see the markup was actually changed with the correct value attribute

            Assert.AreEqual(a.GetAttribute("value"), "aaaaaaaaaaaaaaaaa"); // this throws

           // if we skip the assert, the code below executes but the markup is not even changed
            b.Change("bbbbbbbbbbbbbbbbb");

            Assert.AreEqual(b.GetAttribute("value"), "bbbbbbbbbbbbbbbbb");

            form.Submit();
        }

This is the test project from earlier.
I am trying to skip having to attribute every input with ID in the real project.
What is the correct way to do that?

[egil]

Hi again,

Yeah, this is a little non-obvious admittedly. What happens is that when you call Change, the components render, and a new DOM tree is build, replacing the old one (DOM tree has the IElements in it).

Find actually returns an adapter/wrapper around the IElement, and this adapter automatically retrieves the new element from the new DOM tree after the call from Change. FindAll does the same, if you do not pass false as the second parameter. However, when you pull IElements out of the inputs list, then FindAll cannot update those any more, at least not in the current implementation.

So what you are asserting against on line Assert.AreEqual(a.GetAttribute("value"), "aaaaaaaaaaaaaaaaa"); is actually the old IElement, from before the change.

I do have a plan to fix this, but it is not simple by any means.

Alternatively, you can usually get around this with some more advanced CSS selectors and just use Find, e.g. like the Tree-structural pseudo-classes selectors.

[dady8889]

I see, I will try your suggested changes then. Thank you for the explanation!

[egil]

My pleasure!