dioxus/packages/core/tests/diff_element.rs

use dioxus::dioxus_core::Mutation::*;
use dioxus::dioxus_core::{AttributeValue, ElementId, NoOpMutations};
use dioxus::prelude::*;

#[test]
fn text_diff() {
    fn app() -> Element {
        let gen = generation();
        rsx!( h1 { "hello {gen}" } )
    }

    let mut vdom = VirtualDom::new(app);
    vdom.rebuild(&mut NoOpMutations);

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().edits,
        [SetText { value: "hello 1".to_string(), id: ElementId(2) }]
    );

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().edits,
        [SetText { value: "hello 2".to_string(), id: ElementId(2) }]
    );

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().edits,
        [SetText { value: "hello 3".to_string(), id: ElementId(2) }]
    );
}

#[test]
fn element_swap() {
    fn app() -> Element {
        let gen = generation();

        match gen % 2 {
            0 => rsx!( h1 { "hello 1" } ),
            1 => rsx!( h2 { "hello 2" } ),
            _ => unreachable!(),
        }
    }

    let mut vdom = VirtualDom::new(app);
    vdom.rebuild(&mut NoOpMutations);

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().santize().edits,
        [
            LoadTemplate { name: "template", index: 0, id: ElementId(2,) },
            ReplaceWith { id: ElementId(1,), m: 1 },
        ]
    );

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().santize().edits,
        [
            LoadTemplate { name: "template", index: 0, id: ElementId(1,) },
            ReplaceWith { id: ElementId(2,), m: 1 },
        ]
    );

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().santize().edits,
        [
            LoadTemplate { name: "template", index: 0, id: ElementId(2,) },
            ReplaceWith { id: ElementId(1,), m: 1 },
        ]
    );

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().santize().edits,
        [
            LoadTemplate { name: "template", index: 0, id: ElementId(1,) },
            ReplaceWith { id: ElementId(2,), m: 1 },
        ]
    );
}

#[test]
fn attribute_diff() {
    fn app() -> Element {
        let gen = generation();

        // attributes have to be sorted by name
        let attrs = match gen % 5 {
            0 => vec![Attribute::new(
                "a",
                AttributeValue::Text("hello".into()),
                None,
                false,
            )],
            1 => vec![
                Attribute::new("a", AttributeValue::Text("hello".into()), None, false),
                Attribute::new("b", AttributeValue::Text("hello".into()), None, false),
                Attribute::new("c", AttributeValue::Text("hello".into()), None, false),
            ],
            2 => vec![
                Attribute::new("c", AttributeValue::Text("hello".into()), None, false),
                Attribute::new("d", AttributeValue::Text("hello".into()), None, false),
                Attribute::new("e", AttributeValue::Text("hello".into()), None, false),
            ],
            3 => vec![Attribute::new(
                "d",
                AttributeValue::Text("world".into()),
                None,
                false,
            )],
            _ => unreachable!(),
        };

        rsx!(
            div {
                ..attrs,
                "hello"
            }
        )
    }

    let mut vdom = VirtualDom::new(app);
    vdom.rebuild(&mut NoOpMutations);

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().santize().edits,
        [
            SetAttribute {
                name: "b",
                value: (AttributeValue::Text("hello".into())),
                id: ElementId(1,),
                ns: None,
            },
            SetAttribute {
                name: "c",
                value: (AttributeValue::Text("hello".into())),
                id: ElementId(1,),
                ns: None,
            },
        ]
    );

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().santize().edits,
        [
            SetAttribute { name: "a", value: AttributeValue::None, id: ElementId(1,), ns: None },
            SetAttribute { name: "b", value: AttributeValue::None, id: ElementId(1,), ns: None },
            SetAttribute {
                name: "d",
                value: AttributeValue::Text("hello".into()),
                id: ElementId(1,),
                ns: None,
            },
            SetAttribute {
                name: "e",
                value: AttributeValue::Text("hello".into()),
                id: ElementId(1,),
                ns: None,
            },
        ]
    );

    vdom.mark_dirty(ScopeId::ROOT);
    assert_eq!(
        vdom.render_immediate_to_vec().santize().edits,
        [
            SetAttribute { name: "c", value: AttributeValue::None, id: ElementId(1,), ns: None },
            SetAttribute {
                name: "d",
                value: AttributeValue::Text("world".into()),
                id: ElementId(1,),
                ns: None,
            },
            SetAttribute { name: "e", value: AttributeValue::None, id: ElementId(1,), ns: None },
        ]
    );
}

#[test]
fn diff_empty() {
    fn app() -> Element {
        match generation() % 2 {
            0 => rsx! { div { "hello" } },
            1 => rsx! {},
            _ => unreachable!(),
        }
    }

    let mut vdom = VirtualDom::new(app);
    vdom.rebuild(&mut NoOpMutations);

    vdom.mark_dirty(ScopeId::ROOT);
    let edits = vdom.render_immediate_to_vec().santize().edits;

    assert_eq!(
        edits,
        [
            CreatePlaceholder { id: ElementId(2,) },
            ReplaceWith { id: ElementId(1,), m: 1 },
        ]
    )
}