Fix WithTemplates(nil) function

[sdil]

Summary

Currently using WithTemplates(nil) gives me error like below because it cannot reference the template.Template object correctly

 panic: runtime error: invalid memory address or nil pointer dereference

 -> html/template.(*Template).lookupAndEscapeTemplate
 ->   /opt/homebrew/Cellar/go/1.23.6/libexec/src/html/template/template.go:146

    html/template.(*Template).ExecuteTemplate
      /opt/homebrew/Cellar/go/1.23.6/libexec/src/html/template/template.go:135
    github.com/go-fuego/fuego.StdRenderer.Render
      /Users/fadhil/go/pkg/mod/github.com/go-fuego/fuego@v0.17.0/html.go:95
    github.com/go-fuego/fuego.init.func4
      /Users/fadhil/go/pkg/mod/github.com/go-fuego/fuego@v0.17.0/serialization.go:258
    github.com/go-fuego/fuego.Send
      /Users/fadhil/go/pkg/mod/github.com/go-fuego/fuego@v0.17.0/serialization.go:90
    github.com/go-fuego/fuego.netHttpContext[...].Serialize
      /Users/fadhil/go/pkg/mod/github.com/go-fuego/fuego@v0.17.0/ctx.go:268
    github.com/go-fuego/fuego.Flow[...]
      /Users/fadhil/go/pkg/mod/github.com/go-fuego/fuego@v0.17.0/serve.go:142
    github.com/go-fuego/fuego.registerFuegoController[...].func1
      /Users/fadhil/go/pkg/mod/github.com/go-fuego/fuego@v0.17.0/serve.go:80
    net/http.HandlerFunc.ServeHTTP

This diff should fix the error and the error shouldn't be raised when the default directory ./templates exists.

[EwenQuim]

Thanks! Maintainers never use WithTemplates, so there might be several edge cases not identified.

Can you add a test with require.Panics to ensure the behaviour you coded will remain in the future please?

[EwenQuim]

Also please that your tests pass by running make before sending the PR.

[EwenQuim]

Please add tests

[sdil]

Can you add a test with require.Panics to ensure the behaviour you coded will remain in the future please?

@EwenQuim sorry im not sure how to do this. Can you guide me please?

[EwenQuim]

1. Write a test

func TestWithTemplateNilShouldPanic(...
  fuego.NewServer(
    fuego.WithTemplates(nil)
  )
}

This should raise an error when running make

2. Make the test OK

func TestWithTemplateNilShouldPanic(...
require.Panics(func() {
  fuego.NewServer(
    fuego.WithTemplates(nil)
  )
}}

[dylanhitt]

Hey @sdil an exact example can be found here for this: https://github.com/go-fuego/fuego/blob/main/engine_test.go#L43. You can place it in this test here: https://github.com/go-fuego/fuego/blob/main/server_test.go#L178

😄

[dylanhitt]

So I looked into this some. I'm not really understanding the reasoning for this approach? What is the need to pass WithTemplate(nil)?