✨ (base): Añade with_width() a Container

tests/component_container.rs

@@ -31,3 +31,83 @@ async fn main_kind_renders_a_main_element() {
     assert!(html.starts_with("<main"));
     assert!(html.ends_with("</main>"));
 }
+
+// **< Container::with_width >**********************************************************************
+
+async fn container_html(width: impl Into<Option<container::Width>>) -> String {
+    let mut container = Container::new().with_width(width).with_child(Lc::n("x"));
+    container
+        .render(&mut Context::default())
+        .await
+        .into_string()
+}
+
+#[pagetop::test]
+async fn width_is_none_by_default_and_adds_no_class() {
+    assert_eq!(Container::new().width(), None);
+    // A neutral box: without a width, the component adds no class at all.
+    assert!(!container_html(None).await.contains("container"));
+}
+
+#[pagetop::test]
+async fn width_can_be_set_and_reset() {
+    let width = container::Width::From(Breakpoint::Lg);
+    assert_eq!(Container::new().with_width(width).width(), Some(width));
+    assert_eq!(
+        Container::new().with_width(width).with_width(None).width(),
+        None
+    );
+}
+
+#[pagetop::test]
+async fn width_responsive_adds_the_container_class() {
+    assert!(
+        container_html(container::Width::Responsive)
+            .await
+            .contains(r#"class="container""#)
+    );
+}
+
+#[pagetop::test]
+async fn width_from_uses_the_breakpoint_name() {
+    assert!(
+        container_html(container::Width::From(Breakpoint::Lg))
+            .await
+            .contains(r#"class="container-lg""#)
+    );
+}
+
+#[pagetop::test]
+async fn width_from_a_breakpoint_without_min_width_has_no_name() {
+    // `Xs` has no minimum width, so the class carries no breakpoint name.
+    assert!(
+        container_html(container::Width::From(Breakpoint::Xs))
+            .await
+            .contains(r#"class="container""#)
+    );
+}
+
+#[pagetop::test]
+async fn width_fluid_adds_the_container_fluid_class() {
+    assert!(
+        container_html(container::Width::Fluid)
+            .await
+            .contains(r#"class="container-fluid""#)
+    );
+}
+
+#[pagetop::test]
+async fn width_fluid_max_adds_the_class_and_a_max_width_style() {
+    let html = container_html(container::Width::FluidMax(UnitValue::RelRem(75.0))).await;
+
+    assert!(html.contains("container-fluid"));
+    assert!(html.contains("max-width: 75rem"));
+}
+
+#[pagetop::test]
+async fn width_fluid_max_ignores_a_non_measurable_value() {
+    let html = container_html(container::Width::FluidMax(UnitValue::Auto)).await;
+
+    assert!(html.contains("container-fluid"));
+    assert!(!html.contains("max-width"));
+}