bionic (1) hh_server.1.gz

Provided by: hhvm_3.21.0+dfsg-2ubuntu2_amd64 bug

NAME
       hh_server - Hack language typechecker daemon


SYNOPSIS
       hh_server [--check [--json]] DIRECTORY


DESCRIPTION
       hh_server(1)  is  the actual typechecker that enforces the Hack type system. It is typically accessed via
       hh_client(1); see the documentation for that tool for more information on the Hack type system and how to
       interface with hh_server(1).

       Directly  invoking  hh_server(1)  is of minimal use, since hh_client(1) will start and stop it as needed.
       The only widely useful manual invocation is --check mode.

       With no options, hh_server(1) will start up, do an initial typecheck of DIRECTORY, and continue  running,
       waiting  for  connections  from  hh_client(1).   Again,  this  is not the normal way the server should be
       invoked -- just running hh_client(1) and ignoring the existence of this server binary is  sufficient  for
       common use.


OPTIONS
       --check
              Start  up,  check the DIRECTORY, print type errors in a human-readable format, and then exit. This
              "batch mode" might be useful in cases where a single check is  needed  and  so  starting  a  long-
              running  daemon is not appropriate, such as in a pre-commit hook. The output is intended for human
              consumption, not tools; for tool consumption, see --json below.

       --json If --check is specified, generate machine-readable  JSON  output  instead  of  the  human-readable
              output generated by default.

       --check TARGET
              Start up and check DIRECTORY in the same manner as --check mode. Then, re-check TARGET and attempt
              to add type annotations to locations in those files that are missing. The analysis process is slow
              and  imperfect,  but  often useful. This process can change the code in ways that fail at runtime;
              see http://docs.hhvm.com/hack/tools/introduction for detailed information on how to  combine  this
              mode  with hackificator(1) and hack_remove_soft_types(1) to do a full and safe conversion from PHP
              to Hack.


EXIT STATUS
       If --check is specified, exits with 0 if there are no type errors, nonzero otherwise. Other  exit  values
       are undefined.


ENVIRONMENT and FILES
       Uses  the  same  scheme  for  constructing  a  path  to  a  socket  for  client/server communication that
       hh_client(1) uses. See its documentation for a description.


EXAMPLE
       It might be useful to have a pre-commit hook to make sure that type errors don't sneak into trunk. A hook
       might  want  to  directly  invoke hh_server(1) so that it doesn't need a running daemon. That can be done
       with something like

              hh_server --check /var/www

       and, if that fails, printing its output and rejecting the commit. For tool usage, something like

              hh_server --check --json /var/www

       might be more appropriate; the JSON output can be passed up to a code review tool and displayed there.

       This is only for cases where having a long-running daemon is inappropriate. For normal development usage,
       invoking  hh_client(1)  and  allowing  it  to use the server itself will be much faster to check code and
       return type errors.


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


SEE ALSO
       hh_client(1), hackificator(1), hack_remove_soft_types(1).
       http://docs.hhvm.com/hack/typechecker/setup
       http://www.hacklang.org/

                                                                                                    HH_SERVER(1)