Ubuntu Manpage: hh_client - Interface to Hack language typechecker

name
synopsis
description
modes
exit status
environment
files
bugs
see also

Provided by: hhvm_3.21.0+dfsg-2ubuntu2_amd64

NAME

       hh_client - Interface to Hack language typechecker

SYNOPSIS

       hh_client [MODE] [OPTIONS] [DIRECTORY]

DESCRIPTION

       hh_client(1) is an interface to a static analysis tool which is what enforces most of the Hack language's
       type system. Code must pass validation of this tool in order to be considered  valid  code  in  the  Hack
       language.

       There are several possible MODEs for hh_client(1) (see below). By default, it will invoke the check mode,
       with the current directory as DIRECTORY.  These are reasonable defaults,  meaning  that  most  users  can
       simply invoke the command as

              hh_client

       with no arguments to get a list of type errors across the entire project.

       All of the MODEs accept a DIRECTORY as an optional final argument. This denotes the project upon which to
       operate.  hh_client(1) walks up the filesystem from the DIRECTORY until it finds a file called  .hhconfig
       and  then  operates  on  the  body  of  Hack  language code rooted in this directory.  If no DIRECTORY is
       specified, it uses the current directory  by  default.  This  means  you  may  run  hh_client(1)  in  any
       subdirectory  of  your  project  and  get  type  errors  for  the whole project without ever specifying a
       DIRECTORY explicitly.

       hh_client(1) implements very little logic itself, but rather serves as an interface to  the  hh_server(1)
       daemon. The server will automatically be started and restarted as needed.

MODES

check
The default MODE if none is specified. With no OPTIONS specified, it prints a list of type errors on
standard output, or prints "No errors!" if there were none.

Many OPTIONS affect the output of check mode, sometimes causing it to do completely different things.
(Those can be considered "sub-modes" of check mode.) Many of these options are undergoing considerable
revision and so are not documented here; read the source for a full list.

Widely-useful OPTIONS for check mode include:

--color FILE
Sub-mode which prints out information on what parts of FILE are actually typechecked and which are
not. Due to Hack's partial mode and PHP interoperability, the type system may not know the types
of parts of a program. In this case, it trusts the programmer and carries on. The --color mode
prints out a file with ANSI terminal colors, where green code is actually fully checked, and red
code cannot be fully checked due to such missing type information.

--help Prints information about hh_client(1) and its command line options, and then exits. Many of the
options described there are experimental, especially if they are not described in this man page.

--from EDITOR
Prints output in the format expected by a specific editor. Valid values of EDITOR are emacs and
vim. For usage by other tools, try --json instead.

--json Prints output in a JSON format intended for machine consumption, instead of the output intended
for human consumption that is output by default.

--retries NUM
If the typechecker daemon is busy, try NUM times to connect to it before giving up. Set NUM to 0
to disable retries if the server is not immediately available.

--status
Prints human-readable type error information to standard out and then exits. The default sub-mode
of check if none is specified. This output is not intended for usage by tools, but only for human
consumption. For output intended for tool usage, see the --json and/or --from options.

--version
Prints the current client version, including build ID and build date, and then exits.

--auto-complete
Autocompletes text on STDIN where the cursor is replaced with AUTO332. Returns a newline-
separated list.

--search STRING
Fuzzy search symbol definitions for STRING. Returns a newline-separated list.

start
Explicitly starts the hh_server(1) daemon if it is not already running. This is not normally necessary,
since check mode will start it as needed if it is not running.

stop
Explicitly stops the hh_server(1) daemon if it is running. This is not normally necessary, since the
daemon will exit if it has not been used for an extended period of time.

restart
Explicitly stops and then starts again the hh_server(1) daemon. Fails if the daemon is not currently
running. Restarting the daemon is not normally necessary, since it updates its state in the background,
and hh_client(1) will restart it automatically if the typechecker binaries have been updated.

EXIT STATUS

       For check mode in the --status sub-mode, hh_client(1) returns 0 if there are no type errors, and non-zero
       otherwise.

       Exit statuses for any other invocations are currently undefined and subject to change.

ENVIRONMENT

       USER   Used in combination with the path  to  the  project  root  in  order  to  locate  the  socket  for
              communicating  with  the  running hh_server(1) daemon. Normally set by your login environment, but
              may be unset in some nonstandard setups.

FILES

       .hhconfig
              When determining where the project root  is  in  order  to  figure  out  what  files  to  actually
              typecheck,  hh_client(1)  walks  up the directory tree from the specified DIRECTORY until it finds
              this file. The set of files recursively included in the directory with the .hhconfig file  is  the
              set of files typechecked.

       /tmp/hh_server_$USER/
              The  client  looks  inside this directory for sockets to communicate with the hh_server(1) daemon.
              The sockets are named based on a hash of the absolute path of the project root.

BUGS

       The Hack language is part of the HHVM project. Known bugs can be found at  that  tracker,  and  new  ones
       should be reported there as well: https://github.com/facebook/hhvm/issues