Enable sharding in the IDE

Summary: Similar idea to D64331815. We want to test out sharding in the IDE, but we should make sure we don't absolutely trash UX around it. This lets us double check that sharding works and actually speeds up type checking. If it looks good, then we'll enable it by default.

Reviewed By: grievejia

Differential Revision: D64418245

fbshipit-source-id: 91abe3f1fd5a4a5632cd3c4bfc58547673ecccc4

client/commands/pyre_language_server.py

@@ -712,6 +712,8 @@ async def _query_buck_for_type_errors(
             tempfile.NamedTemporaryFile(mode="w") as argfile,
         ):
             print("--", file=argfile)
+            if self.get_language_server_features().type_error_sharding.is_enabled():
+                print("--enable-sharding\ntrue", file=argfile)
             print(
                 *[
                     argument
@@ -995,6 +997,7 @@ async def handle_overlay_type_errors(
                     "telemetry_version": 3,
                     "new_file_loaded": new_file_loaded,
                     "isolation_dir": isolation_dir,
+                    "sharding_enabled": self.get_language_server_features().type_error_sharding.is_enabled(),
                 },
                 **daemon_status_before.as_telemetry_dict(),
             },

client/language_server/features.py

@@ -99,6 +99,7 @@ def is_disabled(self) -> bool:
 FormattingAvailability = _Availability
 PerTargetTypeErrorsAvailability = CustomAvailability
 PerTargetIsolationDirAvailability = CustomAvailability
+TypeErrorShardingAvailability = CustomAvailability
 PythonAutoTargetsAvailability = CustomAvailability
 SystemPyAutoTargetsAvailability = CustomAvailability
 # TODO: T204372341 remove this once we have rolled out addition and removal features
@@ -123,6 +124,9 @@ class LanguageServerFeatures:
     per_target_isolation_dir: PerTargetIsolationDirAvailability = (
         PerTargetIsolationDirAvailability.from_enabled(False)
     )
+    type_error_sharding: TypeErrorShardingAvailability = (
+        TypeErrorShardingAvailability.from_enabled(False)
+    )
     unsaved_changes: UnsavedChangesAvailability = UnsavedChangesAvailability.DISABLED
     telemetry: TelemetryAvailability = TelemetryAvailability.DISABLED
     completion: CompletionAvailability = CompletionAvailability.DISABLED