Add Trybuild tests for custom_event macro

Author: mc1098

packages/yew-macro/src/custom_event.rs

@@ -9,7 +9,8 @@ pub struct CustomEvent {
     inner_type: Type,
 }
 
-const CUSTOM_EVENT_MSG: &str = "`custom_event` attribute can only be applied to NewType structs";
+const CUSTOM_EVENT_MSG: &str =
+    "custom_event attribute macro can only be applied to NewType structs";
 
 impl Parse for CustomEvent {
     fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {

packages/yew-macro/tests/custom_event/custom_event_fail.rs

@@ -0,0 +1,29 @@
+mod attribute {
+    use yew::custom_event;
+
+    #[custom_event]
+    struct NoAttributeGiven(Event);
+
+    #[custom_event(ident = not a literal string value)]
+    struct AttributeValueNotALitStr(Event);
+
+    #[custom_event("string without ident")]
+    struct StringWithoutIdent(Event);
+}
+
+mod structs {
+    use yew::custom_event;
+
+    #[custom_event(unit_struct)]
+    struct UnitStruct;
+
+    #[custom_event(tuple_struct)]
+    struct TupleStruct(Event, Event);
+
+    #[custom_event(normal_struct)]
+    struct PlainOldStruct {
+        event: Event,
+    }
+}
+
+fn main() {}

packages/yew-macro/tests/custom_event/custom_event_fail.stderr

@@ -0,0 +1,39 @@
+error: unexpected end of input, expected identifier
+ --> $DIR/custom_event_fail.rs:4:5
+  |
+4 |     #[custom_event]
+  |     ^^^^^^^^^^^^^^^
+  |
+  = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected string literal
+ --> $DIR/custom_event_fail.rs:7:28
+  |
+7 |     #[custom_event(ident = not a literal string value)]
+  |                            ^^^
+
+error: expected identifier
+  --> $DIR/custom_event_fail.rs:10:20
+   |
+10 |     #[custom_event("string without ident")]
+   |                    ^^^^^^^^^^^^^^^^^^^^^^
+
+error: custom_event attribute macro can only be applied to NewType structs
+  --> $DIR/custom_event_fail.rs:18:5
+   |
+18 |     struct UnitStruct;
+   |     ^^^^^^^^^^^^^^^^^^
+
+error: custom_event attribute macro can only be applied to NewType structs
+  --> $DIR/custom_event_fail.rs:21:5
+   |
+21 |     struct TupleStruct(Event, Event);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: custom_event attribute macro can only be applied to NewType structs
+  --> $DIR/custom_event_fail.rs:24:5
+   |
+24 | /     struct PlainOldStruct {
+25 | |         event: Event,
+26 | |     }
+   | |_____^

packages/yew-macro/tests/custom_event/custom_event_pass.rs

@@ -0,0 +1,30 @@
+// Inside a module as public custom events can be used outside the module they are defined in.
+mod events {
+    use yew::{custom_event, web_sys::Event};
+
+    // NewType with matching event type and ident - i.e. "custard" can be custard
+    #[custom_event(custard)]
+    pub struct CustardEvent(Event);
+
+    #[custom_event(pbj = "peanut butter jelly")]
+    pub struct PeanutButterJellyEvent(Event);
+}
+
+use yew::custom_event;
+
+// Expand on a custom event
+#[custom_event(dessert)]
+struct DessertEvent(events::CustardEvent);
+
+fn main() {
+    use events::*;
+    use yew::StaticEvent;
+    assert_eq!("custard", custard::event_name());
+    assert_eq!("custard", CustardEvent::event_name());
+
+    assert_eq!("peanut butter jelly", pbj::event_name());
+    assert_eq!("peanut butter jelly", PeanutButterJellyEvent::event_name());
+
+    assert_eq!("dessert", dessert::event_name());
+    assert_eq!("dessert", DessertEvent::event_name());
+}

packages/yew-macro/tests/custom_event_test.rs

@@ -0,0 +1,7 @@
+#[allow(dead_code)]
+#[rustversion::attr(stable(1.51), test)]
+fn tests() {
+    let t = trybuild::TestCases::new();
+    t.pass("tests/custom_event/custom_event_pass.rs");
+    t.compile_fail("tests/custom_event/custom_event_fail.rs");
+}