Fix standalone compilation of iced_test subcrate

Cargo.lock

@@ -2502,6 +2502,7 @@ dependencies = [
 name = "iced_test"
 version = "0.14.0-dev"
 dependencies = [
+ "iced_futures",
  "iced_program",
  "iced_renderer",
  "iced_runtime",

core/src/renderer/null.rs

@@ -259,3 +259,29 @@ impl svg::Renderer for () {
     ) {
     }
 }
+
+impl renderer::Headless for () {
+    async fn new(
+        _default_font: Font,
+        _default_text_size: Pixels,
+        _backend: Option<&str>,
+    ) -> Option<Self>
+    where
+        Self: Sized,
+    {
+        Some(())
+    }
+
+    fn name(&self) -> String {
+        "null renderer".to_owned()
+    }
+
+    fn screenshot(
+        &mut self,
+        _size: Size<u32>,
+        _scale_factor: f32,
+        _background_color: Color,
+    ) -> Vec<u8> {
+        Vec::new()
+    }
+}

test/Cargo.toml

@@ -19,6 +19,9 @@ iced_runtime.workspace = true
 iced_program.workspace = true
 iced_selector.workspace = true
 
+iced_futures.workspace = true
+iced_futures.features = ["thread-pool"]
+
 iced_renderer.workspace = true
 iced_renderer.features = ["fira-sans"]
 

test/src/lib.rs

@@ -83,6 +83,7 @@
 //! [`typewrite`](Simulator::typewrite)—and even perform [_snapshot testing_](Simulator::snapshot)!
 //!
 //! [the classical counter interface]: https://book.iced.rs/architecture.html#dissecting-an-interface
+pub use iced_futures as futures;
 pub use iced_program as program;
 pub use iced_renderer as renderer;
 pub use iced_runtime as runtime;
@@ -122,9 +123,9 @@ pub fn run(
     program: impl program::Program + 'static,
     tests_dir: impl AsRef<Path>,
 ) -> Result<(), Error> {
-    use crate::runtime::futures::futures::StreamExt;
-    use crate::runtime::futures::futures::channel::mpsc;
-    use crate::runtime::futures::futures::executor;
+    use crate::futures::futures::StreamExt;
+    use crate::futures::futures::channel::mpsc;
+    use crate::futures::futures::executor;
 
     use std::ffi::OsStr;
     use std::fs;

test/src/simulator.rs

@@ -76,7 +76,7 @@ where
         let mut renderer = {
             let backend = env::var("ICED_TEST_BACKEND").ok();
 
-            iced_runtime::futures::futures::executor::block_on(Renderer::new(
+            crate::futures::futures::executor::block_on(Renderer::new(
                 default_font,
                 settings.default_text_size,
                 backend.as_deref(),