Support `And` and `Which`

[srpeirce]

Want to write assertions such as:

cut.Should(). HaveElement(cssSelector).Which.HasAttributes("xxx", "yay").And.Text("hello");

[srpeirce]

Looking at FluentAssertions implementation of StringAssertions for reference.

Looks better than what we have now albeit more complex/involved. Will be curious how this works with what I've already implemented (possibly cut.ShouldHaveClass("btn") would become a wrapper to cut.Should().HaveCssClass("btn")....we will see 🤔

I'll probably have first go at this over the weekend for some fun :)

[srpeirce]

To confirm my thinking as sanity check of what I'm building.

For markup

var cut = Render(@<div class="container">
    <button id="one" class="btn">Button 1</button>
    <button id="two" class="btn">Button 2</button>
</div>)

The following should pass - where the And is scoped at the outer div.

cut.Should()
    .HaveElement("#one")
    .And.HaveElement("#two"")
    .And.HaveClass("container");

This should also pass, where the Which is changing the scope to the button element:

cut.Should().HaveElement("#one").Which.HasClass("btn").And.HasChildMarkup("Button 1");
cut.Should().HaveElement("#two").Which.HasClass("btn").And.HasChildMarkup("Button 2");

[srpeirce]

HaveElement should possibly be ContainElement()

[srpeirce]

More feedback:

You might need to distinguish between contains direct child element and contains element at any level. Perhaps make it css selector like thing like "> #foo"

[srpeirce]

Instead of:

cut.Should().HaveElement("#two").Which.HasClass("btn").And.HasChildMarkup("Button 2");

It could be:

cut.Should().HaveElement("#two").Which.Should().HaveClass("btn").And.HaveChildMarkup("Button 2");

This means we only have to write the Have and not the Has - it still reads well.