SSR: Allow function calls to match method calls

This differs from how this used to work before I removed it in that:
a) It's only one direction. Function calls in the pattern can match
method calls in the code, but not the other way around.
b) We now check that the function call in the pattern resolves to the
same function as the method call in the code.

The lack of (b) was the reason I felt the need to remove the feature
before.

1 files changed, 6 insertions, 2 deletions

diff --git a/crates/ra_ssr/src/lib.rs b/crates/ra_ssr/src/lib.rs
index 5a71d4f31..2fb326b45 100644
--- a/crates/ra_ssr/src/lib.rs
+++ b/crates/ra_ssr/src/lib.rs
@@ -202,8 +202,12 @@ impl<'db> MatchFinder<'db> {
                     // For now we ignore rules that have a different kind than our node, otherwise
                     // we get lots of noise. If at some point we add support for restricting rules
                     // to a particular kind of thing (e.g. only match type references), then we can
-                    // relax this.
-                    if rule.pattern.node.kind() != node.kind() {
+                    // relax this. We special-case expressions, since function calls can match
+                    // method calls.
+                    if rule.pattern.node.kind() != node.kind()
+                        && !(ast::Expr::can_cast(rule.pattern.node.kind())
+                            && ast::Expr::can_cast(node.kind()))
+                    {
                         continue;
                     }
                     out.push(MatchDebugInfo {