concise diagnostics for missing props

[Madoshakalaka]

Description

Leveraging the newly stablized #[diagnostics] attributes, we can massively clean up diagnostics for missing props.

#[diagnostics::on_unimplemented] is stablized in rust 1.78, May, 2024
#[diagnostics::do_not_recommend] is stablized in rust 1.85.0, February 20, 2025

This PR raises the MSRV from 1.76 to 1.78.
the use of #[diagnostics::do_not_recommend] seems simply ignored in versions before 1.85.

consider the following example:

use yew::prelude::*;

#[function_component]
pub fn App() -> Html {
    html! {
        <Foo bar={"bar".to_string()} />
    }
}

#[derive(Properties, PartialEq, Clone)]
pub struct FooProps {
    pub bar: String,
    pub baz: u32,
}

#[function_component]
pub fn Foo(props: &FooProps) -> Html {
    html! {}
}

old diagnostics:

new diagnostics (1.78):

new diagnostics (1.85)

Checklist

• I have reviewed my own code
• I have added tests

[github-actions]

Visit the preview URL for this PR (updated for commit f5f68d3):

https://yew-rs--pr3873-missing-props-diagno-8yfivone.web.app

_{(expires Tue, 15 Jul 2025 10:19:10 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

[Madoshakalaka]

I removed these from the tests that have #[derive(Properties)] because it prevents #[diagnostics] from being used. I have no clue how to qualify diagnostics with no_implicit_prelude. If anybody can help it's very appreciated.

[Madoshakalaka]

Hmm.. I think it's impossible to use no_implicit_prelude together with diagnostic

https://doc.rust-lang.org/reference/attributes.html#r-attributes.tool.prelude

Tool attributes are not available if the no_implicit_prelude attribute is used.

[Madoshakalaka]

I think no_implicit_prelude was introduced to improve hygiene, it ensures our macros don't accidentally collide with rust's built-in ones, which could cause false passes in macro tests.

Sadly there seems to be no way around it for now and diagnostic improvements seem worth it.

[github-actions]

Benchmark - core

Yew Master

vnode           fastest       │ slowest       │ median        │ mean          │ samples │ iters
╰─ vnode_clone  2.435 ns      │ 2.763 ns      │ 2.436 ns      │ 2.441 ns      │ 100     │ 1000000000

Pull Request

vnode           fastest       │ slowest       │ median        │ mean          │ samples │ iters
╰─ vnode_clone  2.402 ns      │ 3.765 ns      │ 2.407 ns      │ 2.78 ns       │ 100     │ 1000000000

[github-actions]

Benchmark - SSR

Yew Master

Details

Benchmark	Round	Min (ms)	Max (ms)	Mean (ms)	Standard Deviation
Baseline	10	290.768	296.639	292.137	2.372
Hello World	10	476.648	488.333	478.717	3.469
Function Router	10	1577.379	1588.320	1583.150	3.622
Concurrent Task	10	1005.869	1007.458	1006.657	0.439
Many Providers	10	1084.245	1127.922	1099.981	11.930

Pull Request

Details

Benchmark	Round	Min (ms)	Max (ms)	Mean (ms)	Standard Deviation
Baseline	10	290.845	291.256	290.978	0.137
Hello World	10	506.985	528.298	515.581	7.987
Function Router	10	1587.290	1618.046	1603.822	11.483
Concurrent Task	10	1005.423	1007.097	1006.432	0.454
Many Providers	10	1100.311	1139.490	1117.065	12.264

[github-actions]

Size Comparison

Details

examples	master (KB)	pull request (KB)	diff (KB)	diff (%)
async_clock	100.058	100.058	0	0.000%
boids	168.688	168.688	0	0.000%
communication_child_to_parent	92.301	92.301	0	0.000%
communication_grandchild_with_grandparent	103.483	103.483	0	0.000%
communication_grandparent_to_grandchild	98.490	98.490	0	0.000%
communication_parent_to_child	88.175	88.175	0	0.000%
contexts	104.571	104.571	0	0.000%
counter	84.886	84.886	0	0.000%
counter_functional	85.301	85.301	0	0.000%
dyn_create_destroy_apps	87.811	87.811	0	0.000%
file_upload	99.064	99.064	0	0.000%
function_memory_game	170.675	170.675	0	0.000%
function_router	338.952	338.952	0	0.000%
function_todomvc	163.947	163.947	0	0.000%
futures	237.054	237.054	0	0.000%
game_of_life	104.979	104.979	0	0.000%
immutable	195.396	195.396	0	0.000%
inner_html	80.556	80.556	0	0.000%
js_callback	108.041	108.041	0	0.000%
keyed_list	196.035	196.035	0	0.000%
mount_point	83.864	83.864	0	0.000%
nested_list	113.187	113.187	0	0.000%
node_refs	91.187	91.187	0	0.000%
password_strength	1786.093	1786.093	0	0.000%
portals	93.140	93.140	0	0.000%
router	307.746	307.746	0	0.000%
suspense	112.106	112.106	0	0.000%
timer	88.915	88.915	0	0.000%
timer_functional	95.153	95.153	0	0.000%
todomvc	143.958	143.958	0	0.000%
two_apps	86.250	86.250	0	0.000%
web_worker_fib	135.254	135.254	0	0.000%
web_worker_prime	185.647	185.647	0	0.000%
webgl	83.479	83.479	0	0.000%

✅ None of the examples has changed their size significantly.