flow shadow-file

Makefile

@@ -49,6 +49,7 @@ MODULES=\
   src/server\
   src/services/autocomplete\
   src/services/inference\
+  src/services/interfaceGenerator\
   src/services/port\
   src/stubs\
   src/typing\

hack/utils/tty.ml

@@ -72,7 +72,7 @@ let style_num = function
   | NormalWithBG (text, bg) -> (text_num text) ^ ";" ^ (background_num bg)
   | BoldWithBG (text, bg) -> (text_num text) ^ ";" ^ (background_num bg) ^ ";1"
 
-let print_one ?(color_mode=Color_Auto) c s =
+let print_one ?(color_mode=Color_Auto) ?(out_channel=stdout) c s =
   let should_color = match color_mode with
     | Color_Always -> true
     | Color_Never -> false
@@ -84,14 +84,14 @@ let print_one ?(color_mode=Color_Auto) c s =
             Unix.isatty Unix.stdout && term <> "dumb"
       end in
   if should_color
-  then Printf.printf "\x1b[%sm%s\x1b[0m" (style_num c) (s)
-  else Printf.printf "%s" s
+  then Printf.fprintf out_channel "\x1b[%sm%s\x1b[0m" (style_num c) (s)
+  else Printf.fprintf out_channel "%s" s
 
-let cprint ?(color_mode=Color_Auto) strs =
-  List.iter strs (fun (c, s) -> print_one ~color_mode c s)
+let cprint ?(color_mode=Color_Auto) ?(out_channel=stdout) strs =
+  List.iter strs (fun (c, s) -> print_one ~color_mode ~out_channel c s)
 
-let cprintf ?(color_mode=Color_Auto) c =
-  Printf.ksprintf (print_one ~color_mode c)
+let cprintf ?(color_mode=Color_Auto) ?(out_channel=stdout) c =
+  Printf.ksprintf (print_one ~color_mode ~out_channel c)
 
 let (spinner, spinner_used) =
   let state = ref 0 in

hack/utils/tty.mli

@@ -35,11 +35,11 @@ type color_mode =
   | Color_Auto
 
 (*
- * Print a sequence of colorized strings to stdout, using ANSI color escapes
- * codes.
+ * Print a sequence of colorized strings to stdout/stderr, using ANSI color
+ * escapes codes.
  *)
-val cprint : ?color_mode:color_mode -> (style * string) list -> unit
-val cprintf : ?color_mode:color_mode -> style ->
+val cprint : ?color_mode:color_mode -> ?out_channel:out_channel -> (style * string) list -> unit
+val cprintf : ?color_mode:color_mode -> ?out_channel:out_channel -> style ->
   ('a, unit, string, unit) format4 -> 'a
 
 (* These two functions provide a four-state TTY-friendly spinner that

newtests/shadow_file_command/_flowconfig

@@ -0,0 +1,7 @@
+[ignore]
+
+[include]
+
+[libs]
+
+[options]

newtests/shadow_file_command/function_exports.js

@@ -0,0 +1,4 @@
+// @flow
+
+export function mono(a: number, b: {c: number}) { return a + b.c; };
+export function poly<T: number, U: T, V: U> (a: V) { return a; }

newtests/shadow_file_command/named_class_exports.js

@@ -0,0 +1,21 @@
+// @flow
+
+export class Base<A, B, C> {
+  // Testing infinite type recursion
+  baseInst: Base<number, string, mixed>;
+
+  // Testing forward references
+  childInst: Child<string, number>;
+
+  baseMethod(a: number, b: string) { return a; }
+  overriddenMethod(a: {b: number, c: number}) { return a.b + a.c; }
+};
+
+export class Child<A, B> extends Base<A, B, mixed> {
+  notExported: NotExportedUsed;
+
+  overriddenMethod(a: {b: number}) { return a.b; }
+}
+
+class NotExportedUsed {}
+class NotExportedNotUsed {}

newtests/shadow_file_command/named_variable_exports.js

@@ -0,0 +1,13 @@
+// @flow
+
+export const constExport = 42;
+export let letExport = 43;
+export var varExport = 44;
+
+export type typeExport = number;
+
+type UnexportedT = string;
+export const unexportedAlias = ((0: any): UnexportedT);
+
+class C {}
+export const unexportedNominal = ((0: any): C);

newtests/shadow_file_command/non_flow_file.js

@@ -0,0 +1 @@
+export function addNum(a: number, b: number) { return a + b; }

newtests/shadow_file_command/t.js

@@ -0,0 +1,14 @@
+declare class Class0 {
+}
+declare export class Base<A, B, C> {
+  baseInst: Base<number, string, mixed>;
+  childInst: Child<string, number>;
+
+  baseMethod(a: number, b: string): number;
+}
+
+declare export class Child<A, B> extends Base<A, B, mixed> {
+  notExported: Class0;
+}
+
+

newtests/shadow_file_command/test.js

@@ -0,0 +1,69 @@
+/* @flow */
+
+
+import {suite, test} from '../../tsrc/test/Tester';
+
+export default suite(({addFile, flowCmd}) => [
+  test('class exports', [
+    addFile('named_class_exports.js'),
+    flowCmd(['shadow-file', 'named_class_exports.js']).stdout(`
+      declare class Class0 {
+      }
+      declare export class Base<A, B, C> {
+        baseInst: Base<number, string, mixed>;
+        childInst: Child<string, number>;
+
+        baseMethod(a: number, b: string): number;
+        overriddenMethod(a: {b: number, c: number}): number;
+      }
+      declare export class Child<A, B> extends Base<A, B, mixed> {
+        notExported: Class0;
+
+        overriddenMethod(a: {b: number}): number;
+      }
+    `)
+    .stderr('')
+  ]),
+
+  test('named variable exports', [
+    addFile('named_variable_exports.js'),
+    flowCmd(['shadow-file', 'named_variable_exports.js']).stderr('').stdout(`
+      declare class Class0 {
+      }
+      declare export var constExport: 42;
+      declare export var letExport: 43;
+      export type typeExport = number;
+      declare export var unexportedAlias: string;
+      declare export var unexportedNominal: Class0;
+      declare export var varExport: 44;
+    `)
+  ]),
+
+  test('function exports', [
+    addFile('function_exports.js'),
+    flowCmd(['shadow-file', 'function_exports.js']).stderr('').stdout(`
+      declare export function mono(a: number, b: {c: number}): number;
+      declare export function poly<T: number, U: T, V: U>(a: V): number;
+    `)
+  ]),
+
+  test('non-@flow files', [
+    addFile('non_flow_file.js'),
+    flowCmd(['shadow-file', 'non_flow_file.js']).stderr('').stdout(`
+      declare export function addNum(a: number, b: number): number;
+    `)
+  ]),
+
+  test('type errors halt and stderr', [
+    addFile('type_error.js'),
+    flowCmd(['shadow-file', 'type_error.js']).stdout('').stderr(`
+      type_error.js:3
+        3: export var a: string = 42;
+                                  ^^ number. This type is incompatible with
+        3: export var a: string = 42;
+                         ^^^^^^ string
+      Found 1 error
+      There must be no type errors in order to generate a shadow file!
+    `)
+  ]),
+]);

newtests/shadow_file_command/type_error.js

@@ -0,0 +1,3 @@
+// @flow
+
+export var a: string = 42;

ocp_build_flow.ocp.fb

@@ -33,6 +33,7 @@ begin library "flow-commands"
     "flow-server-env"
     "flow-services-autocomplete"
     "flow-services-inference"
+    "flow-services-interfaceGenerator"
     "flow-typing"
     "hh-find"
     "hh-heap"
@@ -231,6 +232,16 @@ begin library "flow-services-inference"
   ]
 end
 
+begin library "flow-services-interfaceGenerator"
+  sort = true
+  files = begin fb-glob "src/services/interfaceGenerator"
+  end
+  requires = [
+    "flow-typing"
+    "hh-utils-collections"
+  ]
+end
+
 begin library "flow-services-port"
   sort = true
   files = begin fb-glob "src/services/port"

src/commands/commandUtils.ml

@@ -25,7 +25,8 @@ let expand_path file =
     if Path.file_exists path
     then Path.to_string path
     else begin
-      FlowExitStatus.(exit ~msg:"File not found" Input_error)
+      let msg = Printf.sprintf "File not found: %s" (Path.to_string path) in
+      FlowExitStatus.(exit ~msg Input_error)
     end
 
 (* line split/transform utils *)

src/commands/shadowFileCommand.ml

@@ -0,0 +1,76 @@
+(**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the "flow" directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ *)
+
+open CommandUtils
+
+let spf = Printf.sprintf
+
+let name = "shadow-file"
+let spec = {
+  CommandSpec.
+  name;
+  doc = "Given a filename, generate a shadow (.js.flow) file.";
+  usage = Printf.sprintf
+    "Usage: %s %s [OPTIONS] [FILE] [FILE] [FILE]...\n\n\
+      e.g. %s %s foo.js > foo.js.flow\n"
+    CommandUtils.exe_name
+    name
+    CommandUtils.exe_name
+    name
+  ;
+  args = CommandSpec.ArgSpec.(
+    empty
+    |> server_flags
+    |> root_flag
+    |> error_flags
+    |> strip_root_flag
+    |> anon "file" (required string)
+        ~doc:"The file for which a shadow file should be generated"
+  )
+}
+
+let main option_values root error_flags strip_root file () = (
+  let root = guess_root (
+    match root with
+    | Some root -> Some root
+    | None -> Some (expand_path file)
+  ) in
+  let filename = ServerProt.FileName (expand_path file) in
+  let (in_chan, out_chan) = connect option_values root in
+  ServerProt.cmd_to_channel out_chan (ServerProt.GEN_INTERFACES [filename]);
+  let response =
+    (Timeout.input_value in_chan: ServerProt.gen_interface_response)
+  in
+
+  match response with
+  | response::[] -> (
+    match response with
+    | Utils_js.Err (ServerProt.GenIface_TypecheckError (_, errors)) ->
+      let errors = Errors.to_list errors in
+      Errors.print_error_summary ~out_channel:stderr ~flags:error_flags ~strip_root ~root errors;
+      FlowExitStatus.exit
+        ~msg:"\nThere must be no type errors in order to generate a shadow file!"
+        FlowExitStatus.Type_error;
+    | Utils_js.Err (ServerProt.GenIface_UnexpectedError (file_path, error)) ->
+      FlowExitStatus.exit
+        ~msg:(spf "Error: %s: %s" file_path error)
+        FlowExitStatus.Unknown_error
+    | Utils_js.OK (_file, interface) ->
+      print_endline interface
+  )
+  | response ->
+    let msg = spf (
+      "Internal Error: Expected a single interface description from the " ^^
+      "server, but received %d interfaces!"
+    ) (List.length response) in
+    prerr_endline msg
+)
+
+let command = CommandSpec.command spec main

src/common/errors.ml

@@ -238,19 +238,19 @@ let format_info info =
   let formatted = format_reason_color msg in
   String.concat "" (List.map snd formatted)
 
-let print_reason_color ~first ~one_line ~color (message: message) =
+let print_reason_color ?(out_channel=stdout) ~first ~one_line ~color (message: message) =
   let to_print = format_reason_color ~first ~one_line message in
   (if first then Printf.printf "\n");
-  Tty.cprint ~color_mode:color to_print
+  Tty.cprint ~color_mode:color ~out_channel to_print
 
-let print_error_color_old ~one_line ~color (e : error) =
+let print_error_color_old ?(out_channel=stdout) ~one_line ~color (e : error) =
   let { kind; messages; op; trace; extra } = e in
   let messages = prepend_kind_message messages kind in
   let messages = prepend_op_reason messages op in
   let messages = append_extra_info messages extra in
   let messages = append_trace_reasons messages trace in
-  print_reason_color ~first:true ~one_line ~color (List.hd messages);
-  List.iter (print_reason_color ~first:false ~one_line ~color) (List.tl messages)
+  print_reason_color ~out_channel ~first:true ~one_line ~color (List.hd messages);
+  List.iter (print_reason_color ~out_channel ~first:false ~one_line ~color) (List.tl messages)
 
 let file_location_style text = (Tty.Underline Tty.Default, text)
 let default_style text = (Tty.Normal Tty.Default, text)
@@ -531,10 +531,10 @@ let get_pretty_printed_error_new ~stdin_file:stdin_file ~strip_root ~one_line ~r
     else to_print in
   (to_print @ [default_style "\n"])
 
-let print_error_color_new ~stdin_file:stdin_file ~strip_root ~one_line ~color ~root (error : error) =
+let print_error_color_new ?(out_channel=stdout) ~stdin_file:stdin_file ~strip_root ~one_line ~color ~root (error : error) =
   let to_print =
     get_pretty_printed_error_new ~stdin_file ~strip_root ~one_line ~root error in
-  Tty.cprint ~color_mode:color to_print
+  Tty.cprint ~out_channel ~color_mode:color to_print
 
 (* TODO: deprecate this in favor of Reason.json_of_loc *)
 let deprecated_json_props_of_loc loc = Loc.(
@@ -848,7 +848,7 @@ let print_error_deprecated =
     flush oc
 
 (* Human readable output *)
-let print_error_summary ~flags ?(stdin_file=None) ~strip_root ~root errors =
+let print_error_summary ?(out_channel=stdout) ~flags ?(stdin_file=None) ~strip_root ~root errors =
   let error_or_errors n = if n != 1 then "errors" else "error" in
   let truncate = not (flags.Options.show_all_errors) in
   let one_line = flags.Options.one_line in
@@ -858,17 +858,23 @@ let print_error_summary ~flags ?(stdin_file=None) ~strip_root ~root errors =
     else print_error_color_new ~stdin_file ~strip_root ~root
   in
   let print_error_if_not_truncated curr e =
-    (if not(truncate) || curr < 50 then print_error_color ~one_line ~color e);
+    if not(truncate) || curr < 50
+    then print_error_color ~one_line ~color ~out_channel e;
+
     curr + 1
   in
   let total =
     List.fold_left print_error_if_not_truncated 0 errors
   in
   if total > 0 then print_newline ();
   if truncate && total > 50 then (
-    Printf.printf
+    Printf.fprintf
+      out_channel
       "... %d more %s (only 50 out of %d errors displayed)\n"
       (total - 50) (error_or_errors (total - 50)) total;
-    print_endline "To see all errors, re-run Flow with --show-all-errors"
+    Printf.fprintf
+      out_channel
+      "To see all errors, re-run Flow with --show-all-errors";
+    flush out_channel
   ) else
-    Printf.printf "Found %d %s\n" total (error_or_errors total)
+    Printf.fprintf out_channel "Found %d %s\n" total (error_or_errors total)

src/common/errors.mli

@@ -82,6 +82,7 @@ val json_of_errors_with_context :
   Hh_json.json
 
 val print_error_color_new:
+  ?out_channel:out_channel ->
   stdin_file:stdin_file ->
   strip_root:bool ->
   one_line:bool ->
@@ -100,6 +101,7 @@ val print_error_json :
 
 (* Human readable output *)
 val print_error_summary:
+  ?out_channel:out_channel ->
   flags:Options.error_flags ->
   ?stdin_file:stdin_file ->
   strip_root: bool ->