fix: Don't provide add_missing_match_arms assist when upmapping match arm list failed

crates/ide-assists/src/handlers/add_missing_match_arms.rs

@@ -37,9 +37,9 @@ use crate::{utils, AssistContext, AssistId, AssistKind, Assists};
 pub(crate) fn add_missing_match_arms(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
     let match_expr = ctx.find_node_at_offset_with_descend::<ast::MatchExpr>()?;
     let match_arm_list = match_expr.match_arm_list()?;
-    let target_range = ctx.sema.original_range(match_expr.syntax()).range;
+    let arm_list_range = ctx.sema.original_range_opt(match_arm_list.syntax())?;
 
-    if let None = cursor_at_trivial_match_arm_list(ctx, &match_expr, &match_arm_list) {
+    if cursor_at_trivial_match_arm_list(ctx, &match_expr, &match_arm_list).is_none() {
         let arm_list_range = ctx.sema.original_range(match_arm_list.syntax()).range;
         let cursor_in_range = arm_list_range.contains_range(ctx.selection_trimmed());
         if cursor_in_range {
@@ -198,7 +198,7 @@ pub(crate) fn add_missing_match_arms(acc: &mut Assists, ctx: &AssistContext<'_>)
     acc.add(
         AssistId("add_missing_match_arms", AssistKind::QuickFix),
         "Fill match arms",
-        target_range,
+        ctx.sema.original_range(match_expr.syntax()).range,
         |edit| {
             let new_match_arm_list = match_arm_list.clone_for_update();
 
@@ -262,9 +262,8 @@ pub(crate) fn add_missing_match_arms(acc: &mut Assists, ctx: &AssistContext<'_>)
             // Just replace the element that the original range came from
             let old_place = {
                 // Find the original element
-                let old_file_range = ctx.sema.original_range(match_arm_list.syntax());
-                let file = ctx.sema.parse(old_file_range.file_id);
-                let old_place = file.syntax().covering_element(old_file_range.range);
+                let file = ctx.sema.parse(arm_list_range.file_id);
+                let old_place = file.syntax().covering_element(arm_list_range.range);
 
                 // Make `old_place` mut
                 match old_place {
@@ -1922,4 +1921,24 @@ fn foo(t: E) {
 }"#,
         );
     }
+
+    #[test]
+    fn not_applicable_when_match_arm_list_cannot_be_upmapped() {
+        check_assist_not_applicable(
+            add_missing_match_arms,
+            r#"
+macro_rules! foo {
+    ($($t:tt)*) => {
+        $($t)* {}
+    }
+}
+
+enum E { A }
+
+fn main() {
+    foo!(match E::A$0);
+}
+"#,
+        );
+    }
 }

crates/proc-macro-srv/src/server.rs

@@ -17,7 +17,10 @@ use token_stream::TokenStreamBuilder;
 mod symbol;
 pub use symbol::*;
 
-use std::ops::{Bound, Range};
+use std::{
+    iter,
+    ops::{Bound, Range},
+};
 
 use crate::tt;
 
@@ -80,9 +83,7 @@ impl server::TokenStream for RustAnalyzer {
         stream.is_empty()
     }
     fn from_str(&mut self, src: &str) -> Self::TokenStream {
-        use std::str::FromStr;
-
-        Self::TokenStream::from_str(src).expect("cannot parse string")
+        src.parse().expect("cannot parse string")
     }
     fn to_string(&mut self, stream: &Self::TokenStream) -> String {
         stream.to_string()
@@ -101,7 +102,7 @@ impl server::TokenStream for RustAnalyzer {
                     },
                 };
                 let tree = TokenTree::from(group);
-                Self::TokenStream::from_iter(vec![tree])
+                Self::TokenStream::from_iter(iter::once(tree))
             }
 
             bridge::TokenTree::Ident(ident) => {
@@ -111,7 +112,7 @@ impl server::TokenStream for RustAnalyzer {
                 let ident: tt::Ident = tt::Ident { text, span: ident.span };
                 let leaf = tt::Leaf::from(ident);
                 let tree = TokenTree::from(leaf);
-                Self::TokenStream::from_iter(vec![tree])
+                Self::TokenStream::from_iter(iter::once(tree))
             }
 
             bridge::TokenTree::Literal(literal) => {
@@ -123,7 +124,7 @@ impl server::TokenStream for RustAnalyzer {
                 let literal = tt::Literal { text, span: literal.0.span };
                 let leaf = tt::Leaf::from(literal);
                 let tree = TokenTree::from(leaf);
-                Self::TokenStream::from_iter(vec![tree])
+                Self::TokenStream::from_iter(iter::once(tree))
             }
 
             bridge::TokenTree::Punct(p) => {
@@ -134,7 +135,7 @@ impl server::TokenStream for RustAnalyzer {
                 };
                 let leaf = tt::Leaf::from(punct);
                 let tree = TokenTree::from(leaf);
-                Self::TokenStream::from_iter(vec![tree])
+                Self::TokenStream::from_iter(iter::once(tree))
             }
         }
     }
@@ -355,12 +356,12 @@ impl server::Server for RustAnalyzer {
     }
 
     fn intern_symbol(ident: &str) -> Self::Symbol {
-        // FIXME: should be self.interner once the proc-macro api allows is
+        // FIXME: should be `self.interner` once the proc-macro api allows it.
         Symbol::intern(&SYMBOL_INTERNER, &::tt::SmolStr::from(ident))
     }
 
     fn with_symbol_string(symbol: &Self::Symbol, f: impl FnOnce(&str)) {
-        // FIXME: should be self.interner once the proc-macro api allows is
+        // FIXME: should be `self.interner` once the proc-macro api allows it.
         f(symbol.text(&SYMBOL_INTERNER).as_str())
     }
 }

crates/tt/src/lib.rs

@@ -65,7 +65,7 @@ pub mod token_id {
     }
     impl TokenTree {
         pub const fn empty() -> Self {
-            Self::Subtree(Subtree { delimiter: Delimiter::unspecified(), token_trees: vec![] })
+            Self::Subtree(Subtree::empty())
         }
     }