While changing some live component to surface live component,
Dialyzer gave an error like below:
lib/~some_path~/index.sface:1:pattern_match
The pattern can never match the type.
Pattern:
false
Type:
true
As it shows no useful line number, and there was no error when compiling and running the code, I had to find it by commenting out binary search the source code.
Below is part of the index code where it used live component before changing to surface:
<live_component module={SomeModule} id="some-id" data={@some_data} :let={prop}>
<button phx-click={prop.on_click} >button</button>
</.live_component>
After changing to surface live component:
<SomeModule id="some-id" data={@some_data} :let={prop}>
<button phx-click={prop.on_click} >button</button>
</SomeModule>
The problem was getting slot argument as whole prop variable.
I don’t know why it broke Dialyzer, and there was no error from Surface.
But after changing to the following, Dialyzer error disappeared:
<SomeModule id="some-id" data={@some_data} :let={on_click: on_click}>
<button phx-click={on_click} >button</button>
</SomeModule>
I couldn’t make a reproducible example,
so I’m leaving this note just in case anyone stumbles upon a similar problem.
