[flow] Kill support for traces (user-visible part)

Summary:
The traces feature is not that useful nowadays given that we have use_op that makes the error much more understandable. Althrough our errors right now is not perfect, what's currently in the traces are completely non-comprehensible. Instead of dragging on, let's just delete this feature.

This diff starts from the user visible part. We will stop tracking it in errors, and remove the config options. `Context.max_trace_depth` is hardcoded to 0 for now (value when the flag is off), which will be cleaned up in a later diff.

Changelog: [breaking] Support for `--traces` and the corresponding flowconfig has been removed.

Reviewed By: panagosg7

Differential Revision: D56735978

fbshipit-source-id: 0baf317b39ed5893724c3a1118b2fdfdf2fb3afb

src/commands/commandUtils.ml

@@ -887,7 +887,6 @@ module Options_flags = struct
     slow_to_check_logging: Slow_to_check_logging.t;
     strip_root: bool;
     temp_dir: string option;
-    traces: int option;
     verbose: Verbose.t option;
     wait_for_recheck: bool option;
     include_suppressions: bool;
@@ -943,7 +942,6 @@ let options_flags =
       profile
       all
       wait_for_recheck
-      traces
       no_flowlib
       munge_underscore_members
       max_workers
@@ -971,7 +969,6 @@ let options_flags =
         profile;
         all;
         wait_for_recheck;
-        traces;
         no_flowlib;
         munge_underscore_members;
         max_workers;
@@ -1002,7 +999,6 @@ let options_flags =
            (optional bool)
            ~doc:
              "If true, always wait for rechecks to finish before serving commands (default: false)"
-      |> flag "--traces" (optional int) ~doc:"Outline an error path up to a specified level"
       |> flag "--no-flowlib" truthy ~doc:"Do not include embedded declarations"
       |> flag
            "--munge-underscore-members"
@@ -1350,7 +1346,6 @@ let make_options
     opt_casting_syntax =
       Base.Option.value (FlowConfig.casting_syntax flowconfig) ~default:Options.CastingSyntax.Both;
     opt_wait_for_recheck;
-    opt_traces = Base.Option.value options_flags.traces ~default:(FlowConfig.traces flowconfig);
     opt_quiet = options_flags.Options_flags.quiet;
     opt_module_name_mappers = FlowConfig.module_name_mappers flowconfig;
     opt_modules_are_use_strict = FlowConfig.modules_are_use_strict flowconfig;

src/commands/config/flowConfig.ml

@@ -131,7 +131,6 @@ module Opts = struct
     strict_es6_import_export: bool;
     strict_es6_import_export_excludes: string list;
     suppress_types: SSet.t;
-    traces: int;
     ts_syntax: bool;
     one_sided_type_guards: bool;
     use_mixed_in_catch_variables: bool option;
@@ -262,7 +261,6 @@ module Opts = struct
       strict_es6_import_export = false;
       strict_es6_import_export_excludes = [];
       suppress_types = SSet.empty |> SSet.add "$FlowFixMe";
-      traces = 0;
       ts_syntax = false;
       one_sided_type_guards = false;
       use_mixed_in_catch_variables = None;
@@ -1003,7 +1001,6 @@ module Opts = struct
       ("sharedmemory.hash_table_pow", shm_hash_table_pow_parser);
       ("sharedmemory.heap_size", uint (fun opts shm_heap_size -> Ok { opts with shm_heap_size }));
       ("suppress_type", suppress_types_parser);
-      ("traces", uint (fun opts v -> Ok { opts with traces = v }));
       ("types_first.max_files_checked_per_worker", max_files_checked_per_worker_parser);
       ("types_first.max_seconds_for_check_per_worker", max_seconds_for_check_per_worker_parser);
       ("use_mixed_in_catch_variables", use_mixed_in_catch_variables_parser);
@@ -1728,8 +1725,6 @@ let strict_mode c = c.strict_mode
 
 let suppress_types c = c.options.Opts.suppress_types
 
-let traces c = c.options.Opts.traces
-
 let ts_syntax c = c.options.Opts.ts_syntax
 
 let one_sided_type_guards c = c.options.Opts.one_sided_type_guards

src/commands/config/flowConfig.mli

@@ -246,8 +246,6 @@ val strict_mode : config -> StrictModeSettings.t
 
 val suppress_types : config -> SSet.t
 
-val traces : config -> int
-
 val ts_syntax : config -> bool
 
 val one_sided_type_guards : config -> bool

src/common/errors/flow_errors_utils.ml

@@ -781,42 +781,31 @@ let infos_to_messages infos = Base.List.(infos >>= info_to_messages)
 
 let mk_error
     ?(kind = InferError)
-    ?(trace_infos : 'loc info list option)
     ?(root : ('loc * 'loc Friendly.message) option)
     ?(frames : 'loc Friendly.message list option)
     ?(explanations : 'loc Friendly.message list option)
     (loc : 'loc)
     (error_code : Error_codes.error_code option)
     (message : 'loc Friendly.message) : 'loc printable_error =
-  Friendly.(
-    let trace = Base.Option.value_map trace_infos ~default:[] ~f:infos_to_messages in
+  Friendly.
     ( kind,
-      trace,
+      [],
       {
         loc;
         root = Base.Option.map root ~f:(fun (root_loc, root_message) -> { root_loc; root_message });
         code = error_code;
         message = Normal { message; frames; explanations };
       }
     )
-  )
 
 let mk_speculation_error
-    ?(kind = InferError)
-    ?trace_infos
-    ~loc
-    ~root
-    ~frames
-    ~explanations
-    ~error_code
-    speculation_errors =
+    ?(kind = InferError) ~loc ~root ~frames ~explanations ~error_code speculation_errors =
   Friendly.(
-    let trace = Base.Option.value_map trace_infos ~default:[] ~f:infos_to_messages in
     let branches =
       Base.List.map ~f:(fun (score, (_, _, error)) -> (score, error)) speculation_errors
     in
     ( kind,
-      trace,
+      [],
       {
         loc;
         root = Base.Option.map root ~f:(fun (root_loc, root_message) -> { root_loc; root_message });

src/common/errors/flow_errors_utils.mli

@@ -86,7 +86,6 @@ type 'loc printable_error
 
 val mk_error :
   ?kind:error_kind ->
-  ?trace_infos:Loc.t info list ->
   ?root:Loc.t * Loc.t Friendly.message ->
   ?frames:Loc.t Friendly.message list ->
   ?explanations:Loc.t Friendly.message list ->
@@ -97,7 +96,6 @@ val mk_error :
 
 val mk_speculation_error :
   ?kind:error_kind ->
-  ?trace_infos:Loc.t info list ->
   loc:Loc.t ->
   root:(Loc.t * Loc.t Friendly.message) option ->
   frames:Loc.t Friendly.message list ->

src/common/options.ml

@@ -153,7 +153,6 @@ type t = {
   opt_strip_root: bool;
   opt_suppress_types: SSet.t;
   opt_temp_dir: string;
-  opt_traces: int;
   opt_ts_syntax: bool;
   opt_one_sided_type_guards: bool;
   opt_use_mixed_in_catch_variables: bool;
@@ -288,8 +287,6 @@ let max_literal_length opts = opts.opt_max_literal_length
 
 let max_seconds_for_check_per_worker opts = opts.opt_max_seconds_for_check_per_worker
 
-let max_trace_depth opts = opts.opt_traces
-
 let max_workers opts = opts.opt_max_workers
 
 let merge_timeout opts = opts.opt_merge_timeout

src/common/test_utils/test_utils.ml

@@ -29,7 +29,6 @@ let make_options_flags
     ?(quiet = false)
     ?(strip_root = false)
     ?temp_dir
-    ?traces
     ?verbose
     ?wait_for_recheck
     ?(include_suppressions = false)
@@ -51,7 +50,6 @@ let make_options_flags
     quiet;
     strip_root;
     temp_dir;
-    traces;
     verbose;
     slow_to_check_logging = Slow_to_check_logging.default;
     wait_for_recheck;

src/flow_dot_js.ml

@@ -13,7 +13,7 @@ let loc_of_aloc = ALoc.to_loc_exn
 
 let error_of_parse_error source_file (loc, err) =
   Error_message.EParseError (ALoc.of_loc loc, err)
-  |> Flow_error.error_of_msg ~trace_reasons:[] ~source_file
+  |> Flow_error.error_of_msg ~source_file
   |> Flow_intermediate_error.make_intermediate_error ~loc_of_aloc
   |> Flow_intermediate_error.to_printable_error ~loc_of_aloc ~strip_root:None
 
@@ -140,7 +140,6 @@ let stub_metadata ~root ~checked =
     file_options = Files.default_options;
     ignore_non_literal_requires = false;
     max_literal_length = 100;
-    max_trace_depth = 0;
     max_workers = 0;
     missing_module_generators = [];
     namespaces = true;

src/server/error_collator/errorCollator.ml

@@ -31,7 +31,7 @@ let add_suppression_warnings root checked unused warnings =
         if not (CheckedSet.mem_dependency source_file checked) then
           let err =
             let msg = Error_message.EUnusedSuppression loc in
-            Flow_error.error_of_msg ~trace_reasons:[] ~source_file msg
+            Flow_error.error_of_msg ~source_file msg
             |> Flow_intermediate_error.make_intermediate_error ~loc_of_aloc:Fun.id
             |> Flow_intermediate_error.to_printable_error ~loc_of_aloc:Fun.id ~strip_root:(Some root)
           in
@@ -55,7 +55,7 @@ let add_suppression_warnings root checked unused warnings =
       in
       let err =
         Error_message.ECodelessSuppression (loc, code)
-        |> Flow_error.error_of_msg ~trace_reasons:[] ~source_file
+        |> Flow_error.error_of_msg ~source_file
         |> Flow_intermediate_error.make_intermediate_error ~loc_of_aloc:Fun.id
         |> Flow_intermediate_error.to_printable_error ~loc_of_aloc:Fun.id ~strip_root:(Some root)
       in
@@ -74,7 +74,7 @@ let collate_duplicate_providers ~update root =
     let conflict = Loc.{ source = Some duplicate; start = pos; _end = pos } in
     let err =
       Error_message.EDuplicateModuleProvider { module_name; provider; conflict }
-      |> Flow_error.error_of_msg ~trace_reasons:[] ~source_file:duplicate
+      |> Flow_error.error_of_msg ~source_file:duplicate
       |> Flow_intermediate_error.make_intermediate_error ~loc_of_aloc:Fun.id
       |> Flow_intermediate_error.to_printable_error ~loc_of_aloc:Fun.id ~strip_root:(Some root)
     in

src/services/code_action/__tests__/refactor_extract_utils_tests.ml

@@ -53,7 +53,6 @@ let stub_metadata ~root ~checked =
     file_options;
     ignore_non_literal_requires = false;
     max_literal_length = 100;
-    max_trace_depth = 0;
     max_workers = 0;
     missing_module_generators = [];
     namespaces = false;

src/services/inference/inference_utils.ml

@@ -29,24 +29,23 @@ let error_of_docblock_error ~source_file (loc, err) =
           Flow_intermediate_error_types.DisallowedSupportsPlatform
       )
   in
-  Flow_error.error_of_msg ~trace_reasons:[] ~source_file flow_err
+  Flow_error.error_of_msg ~source_file flow_err
 
 let set_of_docblock_errors ~source_file =
   Base.List.fold_left
     ~f:(fun acc err -> Flow_error.ErrorSet.add (error_of_docblock_error ~source_file err) acc)
     ~init:Flow_error.ErrorSet.empty
 
 let error_of_parse_error ~source_file (loc, err) =
-  Error_message.EParseError (ALoc.of_loc loc, err)
-  |> Flow_error.error_of_msg ~trace_reasons:[] ~source_file
+  Error_message.EParseError (ALoc.of_loc loc, err) |> Flow_error.error_of_msg ~source_file
 
 let set_of_parse_error ~source_file =
   error_of_parse_error ~source_file %> Flow_error.ErrorSet.singleton
 
 let error_of_parse_exception ~source_file exn =
   let file_loc = Loc.{ none with source = Some source_file } |> ALoc.of_loc in
   Error_message.EInternal (file_loc, Error_message.ParseJobException exn)
-  |> Flow_error.error_of_msg ~trace_reasons:[] ~source_file
+  |> Flow_error.error_of_msg ~source_file
 
 let set_of_parse_exception ~source_file =
   error_of_parse_exception ~source_file %> Flow_error.ErrorSet.singleton
@@ -57,7 +56,7 @@ let error_of_file_sig_tolerable_error ~source_file err =
     let (SignatureVerificationError sve) = err in
     Error_message.ESignatureVerification (Signature_error.map ALoc.of_loc sve)
   in
-  Flow_error.error_of_msg ~trace_reasons:[] ~source_file flow_err
+  Flow_error.error_of_msg ~source_file flow_err
 
 let set_of_file_sig_tolerable_errors ~source_file =
   Base.List.map ~f:(error_of_file_sig_tolerable_error ~source_file) %> Flow_error.ErrorSet.of_list

src/services/inference/types_js.ml

@@ -151,7 +151,7 @@ let resolve_requires ~transaction ~reader ~options ~profiling ~workers ~parsed ~
 
 let error_set_of_internal_error file (loc, internal_error) =
   Error_message.EInternal (loc, internal_error)
-  |> Flow_error.error_of_msg ~trace_reasons:[] ~source_file:file
+  |> Flow_error.error_of_msg ~source_file:file
   |> Flow_error.ErrorSet.singleton
 
 let calc_deps ~options ~profiling ~components to_merge =

src/typing/__tests__/type_hint_test.ml

@@ -45,7 +45,6 @@ let metadata =
     file_options = Files.default_options;
     ignore_non_literal_requires = false;
     max_literal_length = 100;
-    max_trace_depth = 0;
     max_workers = 0;
     missing_module_generators = [];
     namespaces = false;

src/typing/__tests__/typed_ast_test.ml

@@ -43,7 +43,6 @@ let metadata =
     file_options = Files.default_options;
     ignore_non_literal_requires = false;
     max_literal_length = 100;
-    max_trace_depth = 0;
     max_workers = 0;
     missing_module_generators = [];
     namespaces = false;

src/typing/context.ml

@@ -54,7 +54,6 @@ type metadata = {
   file_options: Files.options;
   ignore_non_literal_requires: bool;
   max_literal_length: int;
-  max_trace_depth: int;
   max_workers: int;
   missing_module_generators: (Str.regexp * string) list;
   namespaces: bool;
@@ -273,7 +272,6 @@ let metadata_of_options options =
     file_options = Options.file_options options;
     ignore_non_literal_requires = Options.should_ignore_non_literal_requires options;
     max_literal_length = Options.max_literal_length options;
-    max_trace_depth = Options.max_trace_depth options;
     max_workers = Options.max_workers options;
     missing_module_generators = Options.missing_module_generators options;
     namespaces = Options.namespaces options;
@@ -552,7 +550,7 @@ let include_suppressions cx = cx.metadata.include_suppressions
 
 let severity_cover cx = cx.ccx.severity_cover
 
-let max_trace_depth cx = cx.metadata.max_trace_depth
+let max_trace_depth _ = 0
 
 let property_maps cx = cx.ccx.sig_cx.property_maps
 
@@ -1013,7 +1011,7 @@ let find_root_id cx id = Type.Constraint.find_root_id cx.ccx.sig_cx.graph id
 
 let on_cyclic_tvar_error cx reason =
   let msg = Error_message.(ETrivialRecursiveDefinition (Reason.loc_of_reason reason, reason)) in
-  let error = Flow_error.error_of_msg ~trace_reasons:[] ~source_file:cx.file msg in
+  let error = Flow_error.error_of_msg ~source_file:cx.file msg in
   if is_verbose cx then
     Utils_js.prerr_endlinef
       "\nCyclic type: %s"

src/typing/context.mli

@@ -91,7 +91,6 @@ type metadata = {
   file_options: Files.options;
   ignore_non_literal_requires: bool;
   max_literal_length: int;
-  max_trace_depth: int;
   max_workers: int;
   missing_module_generators: (Str.regexp * string) list;
   namespaces: bool;

src/typing/errors/flow_error.ml

@@ -13,7 +13,6 @@ type 'loc t = {
   loc: 'loc option;
   msg: 'loc Error_message.t';
   source_file: File_key.t;
-  trace_reasons: 'loc Reason.virtual_reason list;
 }
 
 let loc_of_error { loc; _ } = loc
@@ -24,15 +23,8 @@ let code_of_error err = msg_of_error err |> Error_message.error_code_of_message
 
 let source_file { source_file; _ } = source_file
 
-let trace_reasons { trace_reasons; _ } = trace_reasons
-
-let map_loc_of_error f { loc; msg; source_file; trace_reasons } =
-  {
-    loc = Base.Option.map ~f loc;
-    msg = map_loc_of_error_message f msg;
-    source_file;
-    trace_reasons = Base.List.map ~f:(Reason.map_reason_locs f) trace_reasons;
-  }
+let map_loc_of_error f { loc; msg; source_file } =
+  { loc = Base.Option.map ~f loc; msg = map_loc_of_error_message f msg; source_file }
 
 let kind_of_error err = msg_of_error err |> kind_of_msg
 
@@ -53,5 +45,5 @@ let ordered_reasons ((rl, ru) as reasons) =
   else
     reasons
 
-let error_of_msg ~trace_reasons ~source_file (msg : 'loc Error_message.t') : 'loc t =
-  { loc = loc_of_msg msg; msg; source_file; trace_reasons }
+let error_of_msg ~source_file (msg : 'loc Error_message.t') : 'loc t =
+  { loc = loc_of_msg msg; msg; source_file }

src/typing/errors/flow_error.mli

@@ -15,15 +15,9 @@ val code_of_error : 'loc t -> Error_codes.error_code option
 
 val source_file : 'loc t -> File_key.t
 
-val trace_reasons : 'loc t -> 'loc Reason.virtual_reason list
-
 val kind_of_error : 'loc t -> Flow_errors_utils.error_kind
 
-val error_of_msg :
-  trace_reasons:'loc Reason.virtual_reason list ->
-  source_file:File_key.t ->
-  'loc Error_message.t' ->
-  'loc t
+val error_of_msg : source_file:File_key.t -> 'loc Error_message.t' -> 'loc t
 
 val ordered_reasons : Reason.t * Reason.t -> Reason.t * Reason.t