[flow] Stop including source as supported code actions

Summary:
We shouldn't advertise that we support arbitrary `"source"` because we don't. Doing it will just cause vscode to send us irrelevant ones (e.g. those from eslint). The problem will be especially bad for code-actions on save, because save will be blocked by code actions, and during save we might do expensive dependency analysis that blocks our ability to even respond to code-actions that should be ignored.

Changelog: [misc] Flow language server will stop advertising that we can handle all code actions kinds prefixed with `"source"`. It can help to prevent VSCode sending flow irrelevant code actions to handle during save.

Reviewed By: panagosg7

Differential Revision: D67536771

fbshipit-source-id: 33e4835a5e6c068cbdce6132bac543c85b08df15

newtests/lsp/code-action/test.js

@@ -26,7 +26,7 @@ module.exports = (suite(
         [
           [
             'initialize',
-            '{"codeActionProvider":{"codeActionKinds":["source","source.addMissingImports.flow","source.organizeImports.flow","refactor.extract","quickfix"]}}',
+            '{"codeActionProvider":{"codeActionKinds":["source.addMissingImports.flow","source.organizeImports.flow","refactor.extract","quickfix"]}}',
           ],
         ],
         [...lspIgnoreStatusAndCancellation],

src/lsp/flowLsp.ml

@@ -757,8 +757,7 @@ let do_initialize params : Initialize.result =
     in
     let supported_code_action_kinds =
       if supports_source_actions then
-        CodeActionKind.source
-        :: CodeActionKind.kind_of_string "source.addMissingImports.flow"
+        CodeActionKind.kind_of_string "source.addMissingImports.flow"
         :: CodeActionKind.kind_of_string "source.organizeImports.flow"
         :: supported_code_action_kinds
       else