Implement component name completion in html! for IntelliJ Rust plugin (#2972)

packages/yew-macro/src/html_tree/html_component.rs

@@ -6,6 +6,7 @@ use syn::spanned::Spanned;
 use syn::{Token, Type};
 
 use super::{HtmlChildrenTree, TagTokens};
+use crate::is_ide_completion;
 use crate::props::ComponentProps;
 
 pub struct HtmlComponent {
@@ -25,13 +26,16 @@ impl Parse for HtmlComponent {
         };
 
         if trying_to_close() {
-            return match input.parse::<HtmlComponentClose>() {
-                Ok(close) => Err(syn::Error::new_spanned(
-                    close.to_spanned(),
-                    "this closing tag has no corresponding opening tag",
-                )),
-                Err(err) => Err(err),
-            };
+            let close = input.parse::<HtmlComponentClose>();
+            if !is_ide_completion() {
+                return match close {
+                    Ok(close) => Err(syn::Error::new_spanned(
+                        close.to_spanned(),
+                        "this closing tag has no corresponding opening tag",
+                    )),
+                    Err(err) => Err(err),
+                };
+            }
         }
 
         let open = input.parse::<HtmlComponentOpen>()?;
@@ -48,6 +52,9 @@ impl Parse for HtmlComponent {
         let mut children = HtmlChildrenTree::new();
         let close = loop {
             if input.is_empty() {
+                if is_ide_completion() {
+                    break None;
+                }
                 return Err(syn::Error::new_spanned(
                     open.to_spanned(),
                     "this opening tag has no corresponding closing tag",
@@ -62,7 +69,7 @@ impl Parse for HtmlComponent {
                 }
 
                 let fork = input.fork();
-                break TagTokens::parse_end_content(&fork, |i_fork, tag| {
+                let close = TagTokens::parse_end_content(&fork, |i_fork, tag| {
                     let ty = i_fork.parse().map_err(|e| {
                         syn::Error::new(
                             e.span(),
@@ -76,7 +83,7 @@ impl Parse for HtmlComponent {
                         )
                     })?;
 
-                    if ty != open.ty {
+                    if ty != open.ty && !is_ide_completion() {
                         let open_ty = &open.ty;
                         Err(syn::Error::new_spanned(
                             quote!(#open_ty #ty),
@@ -92,6 +99,7 @@ impl Parse for HtmlComponent {
                         Ok(close)
                     }
                 })?;
+                break Some(close);
             }
             children.parse_child(input)?;
         };
@@ -109,7 +117,7 @@ impl Parse for HtmlComponent {
             ty: open.ty,
             props: open.props,
             children,
-            close: Some(close),
+            close,
         })
     }
 }

packages/yew-macro/src/html_tree/html_element.rs

@@ -10,7 +10,7 @@ use syn::{Block, Expr, Ident, Lit, LitStr, Token};
 use super::{HtmlChildrenTree, HtmlDashedName, TagTokens};
 use crate::props::{ClassesForm, ElementProps, Prop, PropDirective};
 use crate::stringify::{Stringify, Value};
-use crate::{non_capitalized_ascii, Peek, PeekValue};
+use crate::{is_ide_completion, non_capitalized_ascii, Peek, PeekValue};
 
 pub struct HtmlElement {
     pub name: TagName,
@@ -72,6 +72,9 @@ impl Parse for HtmlElement {
         let mut children = HtmlChildrenTree::new();
         loop {
             if input.is_empty() {
+                if is_ide_completion() {
+                    break;
+                }
                 return Err(syn::Error::new_spanned(
                     open.to_spanned(),
                     "this opening tag has no corresponding closing tag",
@@ -86,7 +89,9 @@ impl Parse for HtmlElement {
             children.parse_child(input)?;
         }
 
-        input.parse::<HtmlElementClose>()?;
+        if !input.is_empty() || !is_ide_completion() {
+            input.parse::<HtmlElementClose>()?;
+        }
 
         Ok(Self {
             name: open.name,

packages/yew-macro/src/html_tree/mod.rs

@@ -6,7 +6,7 @@ use syn::parse::{Parse, ParseStream};
 use syn::spanned::Spanned;
 use syn::{braced, token, Token};
 
-use crate::PeekValue;
+use crate::{is_ide_completion, PeekValue};
 
 mod html_block;
 mod html_component;
@@ -101,6 +101,7 @@ impl HtmlTree {
                     Some(HtmlType::List)
                 } else if ident_str.chars().next().unwrap().is_ascii_uppercase()
                     || input.peek(Token![::])
+                    || is_ide_completion() && ident_str.chars().any(|c| c.is_ascii_uppercase())
                 {
                     Some(HtmlType::Component)
                 } else {

packages/yew-macro/src/lib.rs

@@ -98,6 +98,13 @@ fn join_errors(mut it: impl Iterator<Item = syn::Error>) -> syn::Result<()> {
     })
 }
 
+fn is_ide_completion() -> bool {
+    match std::env::var_os("RUST_IDE_PROC_MACRO_COMPLETION_DUMMY_IDENTIFIER") {
+        None => false,
+        Some(dummy_identifier) => !dummy_identifier.is_empty(),
+    }
+}
+
 #[proc_macro_derive(Properties, attributes(prop_or, prop_or_else, prop_or_default))]
 pub fn derive_props(input: TokenStream) -> TokenStream {
     let input = parse_macro_input!(input as DerivePropsInput);