Fix a case where completion was unable to expand a macro

Which caused the macros of the popular `tracing` crate to not offer completions.

The reason is rather complicated: it boils down to macro ignoring their input and completion always choosing the first expansion.

crates/parser/src/grammar/items.rs

@@ -72,8 +72,19 @@ pub(super) fn item_or_macro(p: &mut Parser<'_>, stop_on_r_curly: bool, is_in_ext
     // macro_rules! ()
     // macro_rules! []
     if paths::is_use_path_start(p) {
-        macro_call(p, m);
-        return;
+        paths::use_path(p);
+        // Do not create a MACRO_CALL node here if this isn't a macro call, this causes problems with completion.
+
+        // test_err path_item_without_excl
+        // foo
+        if p.at(T![!]) {
+            macro_call(p, m);
+            return;
+        } else {
+            m.complete(p, ERROR);
+            p.error("expected an item");
+            return;
+        }
     }
 
     m.abandon(p);
@@ -410,8 +421,7 @@ fn fn_(p: &mut Parser<'_>, m: Marker) {
 }
 
 fn macro_call(p: &mut Parser<'_>, m: Marker) {
-    assert!(paths::is_use_path_start(p));
-    paths::use_path(p);
+    assert!(p.at(T![!]));
     match macro_call_after_excl(p) {
         BlockLike::Block => (),
         BlockLike::NotBlock => {

crates/parser/src/tests/top_entries.rs

@@ -30,22 +30,20 @@ fn source_file() {
         TopEntryPoint::SourceFile,
         "@error@",
         expect![[r#"
-        SOURCE_FILE
-          ERROR
-            AT "@"
-          MACRO_CALL
-            PATH
-              PATH_SEGMENT
-                NAME_REF
-                  IDENT "error"
-          ERROR
-            AT "@"
-        error 0: expected an item
-        error 6: expected BANG
-        error 6: expected `{`, `[`, `(`
-        error 6: expected SEMICOLON
-        error 6: expected an item
-    "#]],
+            SOURCE_FILE
+              ERROR
+                AT "@"
+              ERROR
+                PATH
+                  PATH_SEGMENT
+                    NAME_REF
+                      IDENT "error"
+              ERROR
+                AT "@"
+            error 0: expected an item
+            error 6: expected an item
+            error 6: expected an item
+        "#]],
     );
 }