Add silence support

With this patch there is a newly supported section in `.flowconfig`:

```ini
[silence]
/path/to/file.js
/path/to/dir
```

Paths in `[silence]` will still be typechecked, but any
errors will be silenced as if there was a `suppress_comment` comment string
on every line where there are errors.

I called it `silence` to make it stand out from `ignore` and `suppress_comment` as
it currently silences all errors, including lints.

I believe this fixes #869, though I admit I didn't read
the whole issue.

src/commands/commandUtils.ml

@@ -290,18 +290,20 @@ type flowconfig_params = {
    * can defer parsing of the lint settings until after the flowconfig lint settings
    * are known, to properly detect redundant settings (and avoid false positives) *)
   raw_lint_severities: string list;
+  silences: string list;
 }
 
 let list_of_string_arg = function
 | None -> []
 | Some arg_str -> Str.split (Str.regexp ",") arg_str
 
-let collect_flowconfig_flags main ignores_str includes_str lib_str lints_str =
+let collect_flowconfig_flags main ignores_str includes_str lib_str lints_str silence_str =
   let ignores = list_of_string_arg ignores_str in
   let includes = list_of_string_arg includes_str in
   let libs = list_of_string_arg lib_str in
   let raw_lint_severities = list_of_string_arg lints_str in
-  main { ignores; includes; libs; raw_lint_severities; }
+  let silences = list_of_string_arg silence_str in
+  main { ignores; includes; libs; raw_lint_severities; silences; }
 
 let file_options =
   let default_lib_dir ~no_flowlib tmp_dir =
@@ -331,6 +333,12 @@ let file_options =
       Path_matcher.add acc path
     ) Path_matcher.empty paths
   in
+  let silences_of_arg root paths =
+    List.fold_left (fun acc path ->
+      let path = Files.make_path_absolute root path in
+      Path_matcher.add acc path
+    ) Path_matcher.empty paths
+  in
   let lib_paths ~root flowconfig extras =
     let flowtyped_path = Files.get_flowtyped_path root in
     let has_explicit_flowtyped_lib = ref false in
@@ -355,7 +363,7 @@ let file_options =
     | [] -> config_libs
     | _ -> config_libs @ (List.map Path.make extras)
   in
-  fun ~root ~no_flowlib ~temp_dir ~includes ~ignores ~libs flowconfig ->
+  fun ~root ~no_flowlib ~temp_dir ~includes ~ignores ~libs ~silences flowconfig ->
     let default_lib_dir =
       let no_flowlib = no_flowlib || FlowConfig.no_flowlib flowconfig in
       Some (default_lib_dir ~no_flowlib temp_dir)
@@ -368,6 +376,10 @@ let file_options =
       includes
       |> List.rev_append (FlowConfig.includes flowconfig)
       |> includes_of_arg root in
+    let silences =
+      silences
+      |> List.rev_append (FlowConfig.silences flowconfig)
+      |> silences_of_arg root in
     { Files.
       default_lib_dir;
       ignores;
@@ -376,6 +388,7 @@ let file_options =
       module_file_exts = FlowConfig.module_file_exts flowconfig;
       module_resource_exts = FlowConfig.module_resource_exts flowconfig;
       node_resolver_dirnames = FlowConfig.node_resolver_dirnames flowconfig;
+      silences;
     }
 
 let ignore_flag prev = CommandSpec.ArgSpec.(
@@ -402,13 +415,20 @@ let lints_flag prev = CommandSpec.ArgSpec.(
     ~doc:"Specify one or more lint rules, comma separated"
 )
 
+let silence_flag prev = CommandSpec.ArgSpec.(
+  prev
+  |> flag "--silence" (optional string)
+    ~doc:"Specify one or more files/directories to silence, comma separated"
+)
+
 let flowconfig_flags prev = CommandSpec.ArgSpec.(
   prev
   |> collect collect_flowconfig_flags
   |> ignore_flag
   |> include_flag
   |> lib_flag
   |> lints_flag
+  |> silence_flag
 )
 
 type command_params = {
@@ -579,8 +599,8 @@ let make_options ~flowconfig ~lazy_mode ~root (options_flags: Options_flags.t) =
   let open Options_flags in
   let file_options =
     let no_flowlib = options_flags.no_flowlib in
-    let { includes; ignores; libs; raw_lint_severities=_; } = options_flags.flowconfig_flags in
-    file_options ~root ~no_flowlib ~temp_dir ~includes ~ignores ~libs flowconfig
+    let { includes; ignores; libs; raw_lint_severities=_; silences; } = options_flags.flowconfig_flags in
+    file_options ~root ~no_flowlib ~temp_dir ~includes ~ignores ~libs ~silences flowconfig
   in
   let lint_severities = parse_lints_flag
     (FlowConfig.lint_severities flowconfig) options_flags.flowconfig_flags.raw_lint_severities

src/commands/config/flowConfig.ml

@@ -313,6 +313,8 @@ type config = {
   lint_severities: Severity.severity LintSettings.t;
   (* config options *)
   options: Opts.t;
+  (* non-root silence paths *)
+  silences: string list;
 }
 
 module Pp : sig
@@ -367,6 +369,9 @@ end = struct
           (string_of_severity state)))
       lint_severities
 
+  let silences o silences =
+    List.iter (fun silence -> (fprintf o "%s\n" silence)) silences
+
   let config o config =
     section_header o "ignore";
     ignores o config.ignores;
@@ -381,15 +386,19 @@ end = struct
     lints o config;
     fprintf o "\n";
     section_header o "options";
-    options o config
+    options o config;
+    fprintf o "\n";
+    section_header o "silence";
+    silences o config.silences
 end
 
 let empty_config = {
   ignores = [];
   includes = [];
   libs = [];
   lint_severities = LintSettings.default_severities;
-  options = Opts.default_options
+  options = Opts.default_options;
+  silences = []
 }
 
 let group_into_sections lines =
@@ -434,6 +443,10 @@ let parse_ignores config lines =
   let ignores = trim_lines lines in
   { config with ignores; }
 
+let parse_silences config lines =
+  let silences = trim_lines lines in
+  { config with silences; }
+
 let parse_options config lines =
   let open Opts in
   let (>>=) = Result.(>>=) in
@@ -869,6 +882,7 @@ let parse_section config ((section_ln, section), lines) =
   | "libs", _ -> parse_libs config lines
   | "lints", _ -> parse_lints config lines
   | "options", _ -> parse_options config lines
+  | "silence", _ -> parse_silences config lines
   | "version", _ -> parse_version config lines
   | _ -> error section_ln (spf "Unsupported config section: \"%s\"" section)
 
@@ -894,17 +908,19 @@ let read filename =
     |> List.filter is_not_comment in
   parse empty_config lines
 
-let init ~ignores ~includes ~libs ~options ~lints =
+let init ~ignores ~includes ~libs ~lints ~options ~silences =
   let ignores_lines = List.map (fun s -> (1, s)) ignores in
   let includes_lines = List.map (fun s -> (1, s)) includes in
-  let options_lines = List.map (fun s -> (1, s)) options in
   let lib_lines = List.map (fun s -> (1, s)) libs in
   let lint_lines = List.map (fun s -> (1, s)) lints in
+  let options_lines = List.map (fun s -> (1, s)) options in
+  let silences_lines = List.map (fun s -> (1, s)) silences in
   let config = parse_ignores empty_config ignores_lines in
   let config = parse_includes config includes_lines in
-  let config = parse_options config options_lines in
   let config = parse_libs config lib_lines in
   let config = parse_lints config lint_lines in
+  let config = parse_options config options_lines in
+  let config = parse_silences config silences_lines in
   config
 
 let write config oc = Pp.config oc config
@@ -933,6 +949,8 @@ let ignores config = config.ignores
 let includes config = config.includes
 (* library paths. no wildcards *)
 let libs config = config.libs
+(* silence paths. no wildcards *)
+let silences config = config.silences
 
 (* options *)
 let all c = c.options.Opts.all

src/commands/config/flowConfig.mli

@@ -17,8 +17,9 @@ val init:
   ignores: string list ->
   includes: string list ->
   libs: string list ->
-  options: string list ->
   lints: string list ->
+  options: string list ->
+  silences: string list ->
   config
 val write: config -> out_channel -> unit
 
@@ -32,6 +33,8 @@ val ignores: config -> string list
 val includes: config -> string list
 (* library paths. no wildcards *)
 val libs: config -> string list
+(* non-root paths to silence *)
+val silences: config -> string list
 
 (* options *)
 val all: config -> bool

src/commands/configCommands.ml

@@ -43,6 +43,7 @@ module Init = struct
     let includes = flowconfig_flags.CommandUtils.includes in
     let libs = flowconfig_flags.CommandUtils.libs in
     let lints = flowconfig_flags.CommandUtils.raw_lint_severities in
+    let silences = flowconfig_flags.CommandUtils.silences in
 
     let file = Server_files_js.config_file root in
     if Sys.file_exists file
@@ -51,7 +52,7 @@ module Init = struct
       FlowExitStatus.(exit ~msg Invalid_flowconfig)
     end;
 
-    let config = FlowConfig.init ~ignores ~includes ~libs ~options ~lints in
+    let config = FlowConfig.init ~ignores ~includes ~libs ~lints ~options ~silences in
 
     let out = Sys_utils.open_out_no_fail file in
     FlowConfig.write config out;

src/commands/genFlowFilesCommand.ml

@@ -114,7 +114,7 @@ let main option_values root error_flags strip_root ignore_flag
         FlowExitStatus.exit ~msg FlowExitStatus.Commandline_usage_error
       );
 
-      let options = LsCommand.make_options ~root ~ignore_flag ~include_flag in
+      let options = LsCommand.make_options ~root ~ignore_flag ~include_flag ~silence_flag:None in
       let _, libs = Files.init options in
       let next_files =
         LsCommand.get_ls_files ~root ~all:false ~options ~libs ~imaginary:false (Some src)

src/commands/lsCommand.ml

@@ -29,6 +29,7 @@ let spec = {
     |> ignore_flag
     |> include_flag
     |> root_flag
+    |> silence_flag
     |> json_flags
     |> from_flag
     |> flag "--all" no_arg
@@ -106,13 +107,14 @@ let rec iter_get_next ~f get_next =
       List.iter f result;
       iter_get_next ~f get_next
 
-let make_options ~root ~ignore_flag ~include_flag =
+let make_options ~root ~ignore_flag ~include_flag ~silence_flag =
   let flowconfig = FlowConfig.get (Server_files_js.config_file root) in
   let temp_dir = FlowConfig.temp_dir flowconfig in
   let includes = CommandUtils.list_of_string_arg include_flag in
   let ignores = CommandUtils.list_of_string_arg ignore_flag in
   let libs = [] in
-  CommandUtils.file_options ~root ~no_flowlib:true ~temp_dir ~ignores ~includes ~libs flowconfig
+  let silences = CommandUtils.list_of_string_arg silence_flag in
+  CommandUtils.file_options ~root ~no_flowlib:true ~temp_dir ~ignores ~includes ~libs ~silences flowconfig
 
 (* Directories will return a closure that returns every file under that
    directory. Individual files will return a closure that returns just that file
@@ -152,7 +154,7 @@ let concat_get_next get_nexts =
   in concat
 
 let main
-  strip_root ignore_flag include_flag root_flag json pretty from all imaginary reason
+  strip_root ignore_flag include_flag root_flag silence_flag json pretty from all imaginary reason
   input_file root_or_files () =
 
   let files_or_dirs = get_filenames_from_input ~allow_imaginary:true input_file root_or_files in
@@ -172,7 +174,7 @@ let main
       | _ -> None)
   ) in
 
-  let options = make_options ~root ~ignore_flag ~include_flag in
+  let options = make_options ~root ~ignore_flag ~include_flag ~silence_flag in
   let _, libs = Files.init options in
   (* `flow ls` and `flow ls dir` will list out all the flow files *)
   let next_files = (match files_or_dirs with

src/common/files.ml

@@ -18,6 +18,7 @@ type options = {
   module_file_exts: SSet.t;
   module_resource_exts: SSet.t;
   node_resolver_dirnames: string list;
+  silences: Path_matcher.t;
 }
 
 let default_lib_dir options = options.default_lib_dir
@@ -27,6 +28,7 @@ let lib_paths options = options.lib_paths
 let module_file_exts options = options.module_file_exts
 let module_resource_exts options = options.module_resource_exts
 let node_resolver_dirnames options = options.node_resolver_dirnames
+let silences options = options.silences
 
 let node_modules_containers = ref SSet.empty
 
@@ -296,6 +298,10 @@ let is_ignored (options: options) =
 let is_included options f =
   Path_matcher.matches options.includes f
 
+(* true if a file path matches a [silence] path in config *)
+let is_silenced options f =
+  Path_matcher.matches options.silences f
+
 let wanted ~options lib_fileset =
   let is_ignored_ = is_ignored options in
   fun path -> not (is_ignored_ path) && not (SSet.mem path lib_fileset)

src/common/files.mli

@@ -18,6 +18,7 @@ type options = {
   module_file_exts: SSet.t;
   module_resource_exts: SSet.t;
   node_resolver_dirnames: string list;
+  silences: Path_matcher.t;
 }
 
 val default_lib_dir: options -> Path.t option
@@ -27,6 +28,7 @@ val lib_paths: options -> Path.t list
 val module_file_exts: options -> SSet.t
 val module_resource_exts: options -> SSet.t
 val node_resolver_dirnames: options -> string list
+val silences: options -> Path_matcher.t
 
 val node_modules_containers: SSet.t ref
 
@@ -43,6 +45,8 @@ val is_flow_file: options: options -> string -> bool
 val is_ignored: options -> string -> bool
 (* true if a file path matches an [include] path in config *)
 val is_included: options -> string -> bool
+(* true if a file path matches a [silence] path in config *)
+val is_silenced: options -> string -> bool
 
 val is_valid_path: options: options -> string -> bool
 

src/flow_dot_js.ml

@@ -58,7 +58,7 @@ let load_lib_files ~master_cx ~metadata files
       match parse_content lib_file lib_content with
       | ast, [] ->
         let cx, syms = Type_inference_js.infer_lib_file
-          ~metadata ~exclude_syms ~lint_severities:None
+          ~metadata ~exclude_syms ~file_options:None ~lint_severities:None
           lib_file ast
         in
 
@@ -168,7 +168,7 @@ let infer_and_merge ~root filename ast =
   let reqs = Merge_js.Reqs.({ empty with decls }) in
   let file_sigs = Utils_js.FilenameMap.singleton filename file_sig in
   Merge_js.merge_component_strict
-    ~metadata ~lint_severities:None ~file_sigs
+    ~metadata ~file_options:None ~lint_severities:None ~file_sigs
     ~get_ast_unsafe:(fun _ -> ast)
     ~get_docblock_unsafe:(fun _ -> stub_docblock)
     [filename] reqs [] master_cx

src/services/inference/init_js.ml

@@ -74,6 +74,7 @@ let load_lib_files ~master_cx ~options files =
 
       let lib_file = Loc.LibFile file in
       let lint_severities = options.Options.opt_lint_severities in
+      let file_options = Options.file_options options in
       match parse_lib_file options file with
       | Parsing.Parse_ok ast ->
 
@@ -85,7 +86,7 @@ let load_lib_files ~master_cx ~options files =
         in
 
         let cx, syms = Infer.infer_lib_file
-          ~metadata ~exclude_syms ~lint_severities:(Some lint_severities)
+          ~metadata ~exclude_syms ~file_options:(Some file_options) ~lint_severities:(Some lint_severities)
           lib_file ast
         in
 

src/services/inference/merge_service.ml

@@ -95,9 +95,10 @@ let merge_strict_context ~options component =
   in
 
   let metadata = Context.metadata_of_options options in
+  let file_options = Some (Options.file_options options) in
   let lint_severities = Some (Options.lint_severities options) in
   let cx = Merge_js.merge_component_strict
-    ~metadata ~lint_severities ~file_sigs
+    ~metadata ~lint_severities ~file_options ~file_sigs
     ~get_ast_unsafe:Parsing_service_js.get_ast_unsafe
     ~get_docblock_unsafe:Parsing_service_js.get_docblock_unsafe
     component file_reqs dep_cxs master_cx
@@ -136,8 +137,9 @@ let merge_contents_context options file ast info ~ensure_checked_dependencies =
 
   let metadata = Context.metadata_of_options options in
   let lint_severities = Some (Options.lint_severities options) in
+  let file_options = Some (Options.file_options options) in
   let cx = Merge_js.merge_component_strict
-    ~metadata ~lint_severities ~file_sigs
+    ~metadata ~file_options ~lint_severities ~file_sigs
     ~get_ast_unsafe:(fun _ -> ast)
     ~get_docblock_unsafe:(fun _ -> info)
     component file_reqs dep_cxs master_cx