SSR: Allow `self` in patterns.

It's now consistent with other variables in that if the pattern
references self, only the `self` in scope where the rule is invoked will
be accepted. Since `self` doesn't work the same as other paths, this is
implemented by restricting the search to just the current function.
Prior to this change (since path resolution was implemented), having
self in a pattern would just result in no matches.

1 files changed, 9 insertions, 0 deletions

diff --git a/crates/ra_ssr/src/search.rs b/crates/ra_ssr/src/search.rs
index 213dc494f..85ffa2ac2 100644
--- a/crates/ra_ssr/src/search.rs
+++ b/crates/ra_ssr/src/search.rs
@@ -33,6 +33,15 @@ impl<'db> MatchFinder<'db> {
         usage_cache: &mut UsageCache,
         matches_out: &mut Vec<Match>,
     ) {
+        if rule.pattern.contains_self {
+            // If the pattern contains `self` we restrict the scope of the search to just the
+            // current method. No other method can reference the same `self`. This makes the
+            // behavior of `self` consistent with other variables.
+            if let Some(current_function) = self.resolution_scope.current_function() {
+                self.slow_scan_node(&current_function, rule, &None, matches_out);
+            }
+            return;
+        }
         if pick_path_for_usages(&rule.pattern).is_none() {
             self.slow_scan(rule, matches_out);
             return;