From a33330163579ff04ccad1a9e9b7f5d3609ea3954 Mon Sep 17 00:00:00 2001
From: Matt Brown <matthewbrown@slack-corp.com>
Date: Thu, 17 Oct 2024 16:56:39 -0400
Subject: [PATCH] Fix population of interface signatures

---
 src/orchestrator/populator.rs                 | 38 +------------------
 .../refineInterfaceThenCall/input.hack        | 15 ++++++++
 2 files changed, 17 insertions(+), 36 deletions(-)
 create mode 100644 tests/inference/Interface/refineInterfaceThenCall/input.hack

diff --git a/src/orchestrator/populator.rs b/src/orchestrator/populator.rs
index 863fbc54..adf08882 100644
--- a/src/orchestrator/populator.rs
+++ b/src/orchestrator/populator.rs
@@ -741,42 +741,8 @@ fn inherit_methods_from_parent(
             }
         }
 
-        if let Some(existing_declaring_class) = storage.declaring_method_ids.get(method_name) {
-            if existing_declaring_class != declaring_class {
-                let existing_declaring_class_storage = if existing_declaring_class == &storage.name
-                {
-                    &storage
-                } else if let Some(storage) = codebase.classlike_infos.get(existing_declaring_class)
-                {
-                    storage
-                } else {
-                    continue;
-                };
-
-                if !matches!(existing_declaring_class_storage.kind, SymbolKind::Interface) {
-                    if let Some(functionlike_storage) = codebase
-                        .functionlike_infos
-                        .get(&(existing_declaring_class_storage.name, *method_name))
-                    {
-                        if let Some(method_info) = &functionlike_storage.method_info {
-                            if !method_info.is_abstract {
-                                continue;
-                            }
-
-                            if let Some(functionlike_storage) = codebase
-                                .functionlike_infos
-                                .get(&(storage.name, *method_name))
-                            {
-                                if let Some(method_info) = &functionlike_storage.method_info {
-                                    if method_info.is_abstract {
-                                        continue;
-                                    }
-                                }
-                            }
-                        }
-                    }
-                }
-            }
+        if let Some(_) = storage.declaring_method_ids.get(method_name) {
+            continue;
         }
 
         storage
diff --git a/tests/inference/Interface/refineInterfaceThenCall/input.hack b/tests/inference/Interface/refineInterfaceThenCall/input.hack
new file mode 100644
index 00000000..fb0ad2a0
--- /dev/null
+++ b/tests/inference/Interface/refineInterfaceThenCall/input.hack
@@ -0,0 +1,15 @@
+interface I {
+    public function foo(): arraykey;
+}
+
+interface IChild extends I {
+    public function foo(): string;
+}
+
+function bar(I $i): string {
+    if ($i is IChild) {
+        return $i->foo();
+    } else {
+        return '';
+    }
+}
\ No newline at end of file