Unit testing phoenix component gives warning

Questions / Help
1

as per Phoenix.LiveViewTest — Phoenix LiveView v0.18.16 my unit tests take the following format

  test "test1" do
    assigns = %{}

    name="abcd"

    component_string =
      rendered_to_string(~H"""
        <Web.Components.component1 name={name} />
      """)

      # assertions here
  end

the test itself works fine, but i get a warning saying the following

Using variables in HEEx templates are discouraged as they disable change tracking. You are only allowed to access variables defined by Elixir control-flow structures, such as if/case/for, or those defined by the special attributes :let/:if/ ....

this is because i’m accessing the name variable. i can of course inline this, but i have made it simple in this case, in my actual project this is a more complex object.

2

Just like in function components heex does expect you to use an assigns map to privide data and use @name syntax.

3

thanks for the information, i actually tried making an assigns object and then passing it like this

    assigns = %{}
    assigns = assign(assigns, :name, "abcd")

  component_string =
      rendered_to_string(~H"""
        <Web.Components.component1 {assigns}/>
      """)

but i ended up with the following error here

ssign/3 expects a socket from Phoenix.LiveView/Phoenix.LiveComponent or an assigns map from Phoenix.Component as first argument, got: %{}You passed an assigns map that does not have the relevant change tracking information. This typically means you are calling a function component by hand instead of using the HEEx template syntax. If you are using HEEx, make sure you are calling a component using:

4

The APIs for modifing assigns only work with the change tracked structs you get from liveview. If you’re using a plain map you can just edit it like any other map. You won’t need change tracking in tests anyways.