fix(declarations): remove unused suppression code

Related to the previous commit, this backs out some of the code
in facebook#4916 related to file error suppression in the merge phase.

This has the benefit of fixing erroneous ignoring of comment
suppressions within those files, which was causing unexpected
consequences.

src/services/inference/init_js.ml

@@ -64,7 +64,6 @@ let load_lib_files ~sig_cx ~options ~reader files =
          (fun (exclude_syms, results) file ->
            let lib_file = File_key.LibFile file in
            let lint_severities = options.Options.opt_lint_severities in
-           let file_options = Options.file_options options in
            let%lwt result = parse_lib_file ~reader options file in
            Lwt.return
              (match result with
@@ -95,7 +94,6 @@ let load_lib_files ~sig_cx ~options ~reader files =
                    ast
                    ~exclude_syms
                    ~lint_severities
-                   ~file_options:(Some file_options)
                    ~file_sig
                in
                let errors = Context.errors cx in

src/services/inference/merge_service.ml

@@ -125,7 +125,6 @@ let merge_context_generic ~options ~reader ~get_ast_unsafe ~get_file_sig_unsafe
   let (master_cx, dep_cxs, file_reqs) = reqs_of_component ~reader component required in
   let metadata = Context.metadata_of_options options in
   let lint_severities = Options.lint_severities options in
-  let file_options = Some (Options.file_options options) in
   let strict_mode = Options.strict_mode options in
   let get_aloc_table_unsafe =
     Parsing_heaps.Reader_dispatcher.get_sig_ast_aloc_table_unsafe ~reader
@@ -134,7 +133,6 @@ let merge_context_generic ~options ~reader ~get_ast_unsafe ~get_file_sig_unsafe
     Merge_js.merge_component
       ~metadata
       ~lint_severities
-      ~file_options
       ~strict_mode
       ~file_sigs
       ~phase
@@ -221,7 +219,6 @@ let merge_contents_context ~reader options file ast info file_sig =
   in
   let metadata = Context.metadata_of_options options in
   let lint_severities = Options.lint_severities options in
-  let file_options = Some (Options.file_options options) in
   let strict_mode = Options.strict_mode options in
   let get_aloc_table_unsafe =
     Parsing_heaps.Reader_dispatcher.get_sig_ast_aloc_table_unsafe ~reader
@@ -230,7 +227,6 @@ let merge_contents_context ~reader options file ast info file_sig =
     Merge_js.merge_component
       ~metadata
       ~lint_severities
-      ~file_options
       ~strict_mode
       ~file_sigs
       ~get_ast_unsafe:(fun _ -> (comments, aloc_ast))

src/typing/merge_js.ml

@@ -347,7 +347,6 @@ let detect_non_voidable_properties cx =
 let merge_component
     ~metadata
     ~lint_severities
-    ~file_options
     ~strict_mode
     ~file_sigs
     ~get_ast_unsafe
@@ -416,7 +415,6 @@ let merge_component
             comments
             ast
             ~lint_severities
-            ~file_options
             ~file_sig
         in
         (cx :: cxs, tast :: tasts, FilenameMap.add filename cx impl_cxs))

src/typing/merge_js.mli

@@ -26,7 +26,6 @@ end
 val merge_component :
   metadata:Context.metadata ->
   lint_severities:Severity.severity LintSettings.t ->
-  file_options:Files.options option ->
   strict_mode:StrictModeSettings.t ->
   file_sigs:File_sig.With_ALoc.t Utils_js.FilenameMap.t ->
   get_ast_unsafe:(File_key.t -> get_ast_return) ->

src/typing/type_inference_js.ml

@@ -333,23 +333,9 @@ let scan_for_lint_suppressions =
     Context.add_severity_cover cx (Context.file cx) severity_cover;
     Context.add_lint_suppressions cx suppression_locs
 
-let scan_for_suppressions cx lint_severities file_options comments =
-  let filename = File_key.to_string (Context.file cx) in
-  let declaration =
-    match file_options with
-    | Some file_options -> Files.is_declaration file_options filename
-    | None -> false
-  in
-  if declaration then
-    (* Declaration mode.
-     * We don't report any warnings or errors. *)
-    Context.remove_all_errors cx
-  else
-    (* Scan comments for line suppressions. *)
-    scan_for_error_suppressions cx comments;
-  scan_for_lint_suppressions cx lint_severities comments;
-
-  ()
+let scan_for_suppressions cx lint_severities comments =
+  scan_for_error_suppressions cx comments;
+  scan_for_lint_suppressions cx lint_severities comments
 
 let add_require_tvars =
   let add cx desc loc =
@@ -385,7 +371,7 @@ let add_require_tvars =
 
 (* build module graph *)
 (* Lint suppressions are handled iff lint_severities is Some. *)
-let infer_ast ~lint_severities ~file_options ~file_sig cx filename comments aloc_ast =
+let infer_ast ~lint_severities ~file_sig cx filename comments aloc_ast =
   assert (Context.is_checked cx);
 
   Flow_js.Cache.clear ();
@@ -432,7 +418,7 @@ let infer_ast ~lint_severities ~file_options ~file_sig cx filename comments aloc
   (* infer *)
   Flow_js.flow_t cx (init_exports, local_exports_var);
   let typed_statements = infer_core cx aloc_statements in
-  scan_for_suppressions cx lint_severities file_options comments;
+  scan_for_suppressions cx lint_severities comments;
 
   let module_t = Import_export.mk_module_t cx reason in
   Context.add_module cx module_ref module_t;
@@ -471,7 +457,7 @@ let with_libdef_builtins cx f =
    a) symbols from prior library loads are suppressed if found,
    b) bindings are added as properties to the builtin object
  *)
-let infer_lib_file ~exclude_syms ~lint_severities ~file_options ~file_sig cx ast =
+let infer_lib_file ~exclude_syms ~lint_severities ~file_sig cx ast =
   let aloc_ast = Ast_loc_utils.loc_to_aloc_mapper#program ast in
   let (_, _, comments) = ast in
   let (_, aloc_statements, _) = aloc_ast in
@@ -487,7 +473,7 @@ let infer_lib_file ~exclude_syms ~lint_severities ~file_options ~file_sig cx ast
 
   with_libdef_builtins cx (fun () ->
       ignore (infer_core cx aloc_statements : (ALoc.t, ALoc.t * Type.t) Ast.Statement.t list);
-      scan_for_suppressions cx lint_severities file_options comments);
+      scan_for_suppressions cx lint_severities comments);
 
   ( module_scope
   |> Scope.(

src/typing/type_inference_js.mli

@@ -8,7 +8,6 @@
 (* Lint suppressions are handled iff lint_severities is Some. *)
 val infer_ast :
   lint_severities:Severity.severity LintSettings.t ->
-  file_options:Files.options option ->
   file_sig:File_sig.With_ALoc.t ->
   Context.t ->
   File_key.t ->
@@ -20,7 +19,6 @@ val infer_ast :
 val infer_lib_file :
   exclude_syms:SSet.t ->
   lint_severities:Severity.severity LintSettings.t ->
-  file_options:Files.options option ->
   file_sig:File_sig.With_ALoc.t ->
   Context.t ->
   (Loc.t, Loc.t) Flow_ast.program ->

testgen/flowtestgen_utils.ml

@@ -681,7 +681,6 @@ let flow_check (code : string) : string option =
           builtins_ast
           ~exclude_syms:SSet.empty
           ~lint_severities
-          ~file_options:None
           ~file_sig:(File_sig.abstractify_locs builtins_file_sig)
       in
       let () =

tests/config_declarations/config_declarations.exp

@@ -20,5 +20,13 @@ Unused suppression comment.
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 
+Warning ------------------------------------------------------------------------------------------------------- B.js:1:1
 
-Found 1 error and 1 warning
+Unused suppression comment.
+
+   1| // $FlowFixMe
+      ^^^^^^^^^^^^^
+
+
+
+Found 1 error and 2 warnings