Split Hack out from PHP, modernize

fixes #1738

- Replace previous `hh_client` usage with LSP client
- Add `HHAST` linter
- Split Hack from PHP: Hack is increasingly diverging from PHP:
  - Hack tools do not understand PHP
  - Most PHP tools do not handle Hack code well (including vim's syntax
    highightling files)
  - http://github.com/hhvm/vim-hack now sets filetype to `hack`

10 files changed, 126 insertions, 61 deletions

diff --git a/README.md b/README.md
index bc7b1ee6..07de881d 100644
--- a/README.md
+++ b/README.md
@@ -126,6 +126,7 @@ formatting.
 | GLSL | [glslang](https://github.com/KhronosGroup/glslang), [glslls](https://github.com/svenstaro/glsl-language-server) |
 | Go | [gofmt](https://golang.org/cmd/gofmt/), [goimports](https://godoc.org/golang.org/x/tools/cmd/goimports), [go vet](https://golang.org/cmd/vet/) !!, [golint](https://godoc.org/github.com/golang/lint), [gotype](https://godoc.org/golang.org/x/tools/cmd/gotype) !!, [gometalinter](https://github.com/alecthomas/gometalinter) !!, [go build](https://golang.org/cmd/go/) !!, [gosimple](https://github.com/dominikh/go-tools/tree/master/cmd/gosimple) !!, [staticcheck](https://github.com/dominikh/go-tools/tree/master/cmd/staticcheck) !! |
 | GraphQL | [eslint](http://eslint.org/), [gqlint](https://github.com/happylinks/gqlint), [prettier](https://github.com/prettier/prettier) |
+| Hack | [hack](http://hacklang.org/), [hackfmt](https://github.com/facebook/hhvm/tree/master/hphp/hack/hackfmt), [hhast](https://github.com/hhvm/hhast) |
 | Haml | [haml-lint](https://github.com/brigade/haml-lint) |
 | Handlebars | [ember-template-lint](https://github.com/rwjblue/ember-template-lint) |
 | Haskell | [brittany](https://github.com/lspitzner/brittany), [ghc](https://www.haskell.org/ghc/), [cabal-ghc](https://www.haskell.org/cabal/), [stack-ghc](https://haskellstack.org/), [stack-build](https://haskellstack.org/) !!, [ghc-mod](https://github.com/DanielG/ghc-mod), [stack-ghc-mod](https://github.com/DanielG/ghc-mod), [hlint](https://hackage.haskell.org/package/hlint), [hdevtools](https://hackage.haskell.org/package/hdevtools), [hfmt](https://github.com/danstiner/hfmt) |
@@ -152,7 +153,7 @@ formatting.
 | Objective-C++ | [clang](http://clang.llvm.org/) |
 | OCaml | [merlin](https://github.com/the-lambda-church/merlin) see `:help ale-ocaml-merlin` for configuration instructions, [ols](https://github.com/freebroccolo/ocaml-language-server) |
 | Perl | [perl -c](https://perl.org/), [perl-critic](https://metacpan.org/pod/Perl::Critic), [perltidy](https://metacpan.org/pod/distribution/Perl-Tidy/bin/perltidy) |
-| PHP | [hack](http://hacklang.org/), [hackfmt](https://github.com/facebook/flow/tree/master/hack/hackfmt), [langserver](https://github.com/felixfbecker/php-language-server), [phan](https://github.com/phan/phan) see `:help ale-php-phan` to instructions, [php -l](https://secure.php.net/), [phpcs](https://github.com/squizlabs/PHP_CodeSniffer), [phpmd](https://phpmd.org), [phpstan](https://github.com/phpstan/phpstan), [phpcbf](https://github.com/squizlabs/PHP_CodeSniffer), [php-cs-fixer](http://cs.sensiolabs.org/) |
+| PHP | [langserver](https://github.com/felixfbecker/php-language-server), [phan](https://github.com/phan/phan) see `:help ale-php-phan` to instructions, [php -l](https://secure.php.net/), [phpcs](https://github.com/squizlabs/PHP_CodeSniffer), [phpmd](https://phpmd.org), [phpstan](https://github.com/phpstan/phpstan), [phpcbf](https://github.com/squizlabs/PHP_CodeSniffer), [php-cs-fixer](http://cs.sensiolabs.org/) |
 | PO | [alex](https://github.com/wooorm/alex) !!, [msgfmt](https://www.gnu.org/software/gettext/manual/html_node/msgfmt-Invocation.html), [proselint](http://proselint.com/), [write-good](https://github.com/btford/write-good) |
 | Pod | [alex](https://github.com/wooorm/alex) !!, [proselint](http://proselint.com/), [write-good](https://github.com/btford/write-good) |
 | Pony | [ponyc](https://github.com/ponylang/ponyc) |
diff --git a/ale_linters/hack/hack.vim b/ale_linters/hack/hack.vim
new file mode 100644
index 00000000..0253767a
--- /dev/null
+++ b/ale_linters/hack/hack.vim
@@ -0,0 +1,27 @@
+" Author: Fred Emmott <fe@fb.com>
+" Description: Hack support via `hack lsp`
+
+call ale#Set('hack_hhclient_executable', 'hh_client')
+
+function! ale_linters#hack#hack#GetProjectRoot(buffer) abort
+    let l:hhconfig = ale#path#FindNearestFile(a:buffer, '.hhconfig')
+    return !empty(l:hhconfig) ? fnamemodify(l:hhconfig, ':h') : ''
+endfunction
+
+function! ale_linters#hack#hack#GetExecutable(buffer) abort
+    return ale#Var(a:buffer, 'hack_hhclient_executable')
+endfunction
+
+
+function! ale_linters#hack#hack#GetCommand(buffer) abort
+    let l:executable = ale_linters#hack#hack#GetExecutable(a:buffer)
+    return ale#Escape(l:executable).' lsp --from vim-ale'
+endfunction
+
+call ale#linter#Define('hack', {
+\   'name': 'hack',
+\   'lsp': 'stdio',
+\   'executable_callback': 'ale_linters#hack#hack#GetExecutable',
+\   'command_callback': 'ale_linters#hack#hack#GetCommand',
+\   'project_root_callback': 'ale_linters#hack#hack#GetProjectRoot',
+\})
diff --git a/ale_linters/hack/hhast.vim b/ale_linters/hack/hhast.vim
new file mode 100644
index 00000000..8ff5a962
--- /dev/null
+++ b/ale_linters/hack/hhast.vim
@@ -0,0 +1,34 @@
+" Author: Fred Emmott <fe@fb.com>
+" Description: Hack support via `hhast lsp`
+
+call ale#Set('hack_hhast_executable', 'vendor/bin/hhast-lint')
+
+function! ale_linters#hack#hhast#GetProjectRoot(buffer) abort
+    let l:root = ale_linters#hack#hack#GetProjectRoot(a:buffer)
+    if empty(l:root)
+      return ''
+    endif
+    let l:hhast_config = findfile('hhast-lint.json', l:root)
+    return !empty(l:hhast_config) ? l:root : ''
+endfunction
+
+function! ale_linters#hack#hhast#GetExecutable(buffer) abort
+    let l:root = ale_linters#hack#hhast#GetProjectRoot(a:buffer)
+    let l:relative = ale#Var(a:buffer, 'hack_hhast_executable')
+    let l:absolute = findfile(l:relative, l:root)
+    return !empty(l:absolute) ? l:absolute : ''
+endfunction
+
+
+function! ale_linters#hack#hhast#GetCommand(buffer) abort
+    let l:executable = ale_linters#hack#hhast#GetExecutable(a:buffer)
+    return ale#Escape(l:executable).' --mode lsp --from vim-ale'
+endfunction
+
+call ale#linter#Define('hack', {
+\   'name': 'hhast',
+\   'lsp': 'stdio',
+\   'executable_callback': 'ale_linters#hack#hhast#GetExecutable',
+\   'command_callback': 'ale_linters#hack#hhast#GetCommand',
+\   'project_root_callback': 'ale_linters#hack#hhast#GetProjectRoot',
+\})
diff --git a/ale_linters/php/hack.vim b/ale_linters/php/hack.vim
deleted file mode 100644
index 77d3a588..00000000
--- a/ale_linters/php/hack.vim
+++ /dev/null
@@ -1,28 +0,0 @@
-" Author: Zefei Xuan <https://github.com/zefei>
-" Description: Hack type checking (http://hacklang.org/)
-
-function! ale_linters#php#hack#Handle(buffer, lines) abort
-    let l:pattern = '^\(.*\):\(\d\+\):\(\d\+\),\(\d\+\): \(.\+])\)$'
-    let l:output = []
-
-    for l:match in ale#util#GetMatches(a:lines, l:pattern)
-        if a:buffer != bufnr(l:match[1])
-            continue
-        endif
-
-        call add(l:output, {
-        \   'lnum': l:match[2] + 0,
-        \   'col': l:match[3] + 0,
-        \   'text': l:match[5],
-        \})
-    endfor
-
-    return l:output
-endfunction
-
-call ale#linter#Define('php', {
-\   'name': 'hack',
-\   'executable': 'hh_client',
-\   'command': 'hh_client --retries 0 --retry-if-init false',
-\   'callback': 'ale_linters#php#hack#Handle',
-\})
diff --git a/autoload/ale/fixers/hackfmt.vim b/autoload/ale/fixers/hackfmt.vim
index b5bf0dc5..bf2d4f71 100644
--- a/autoload/ale/fixers/hackfmt.vim
+++ b/autoload/ale/fixers/hackfmt.vim
@@ -1,12 +1,12 @@
 " Author: Sam Howie <samhowie@gmail.com>
 " Description: Integration of hackfmt with ALE.
 
-call ale#Set('php_hackfmt_executable', 'hackfmt')
-call ale#Set('php_hackfmt_options', '')
+call ale#Set('hack_hackfmt_executable', 'hackfmt')
+call ale#Set('hack_hackfmt_options', '')
 
 function! ale#fixers#hackfmt#Fix(buffer) abort
-    let l:executable = ale#Var(a:buffer, 'php_hackfmt_executable')
-    let l:options = ale#Var(a:buffer, 'php_hackfmt_options')
+    let l:executable = ale#Var(a:buffer, 'hack_hackfmt_executable')
+    let l:options = ale#Var(a:buffer, 'hack_hackfmt_options')
 
     return {
     \   'command': ale#Escape(l:executable)
diff --git a/doc/ale-hack.txt b/doc/ale-hack.txt
new file mode 100644
index 00000000..0fbe5c45
--- /dev/null
+++ b/doc/ale-hack.txt
@@ -0,0 +1,42 @@
+===============================================================================
+ALE Hack Integration                                         *ale-hack-options*
+
+===============================================================================
+hack                                                            *ale-hack-hack*
+
+g:ale_hack_hhclient_executable                 *g:ale_hack_hhclient_executable*
+                                               *b:ale_hack_hhclient_executable*
+
+  Type: |String|
+  Default: `'hh_client'`
+
+  This variable can be set to use a specific executable to interact with the
+  Hack typechecker.
+
+
+===============================================================================
+hackfmt                                                      *ale-hack-hackfmt*
+
+g:ale_hack_hackfmt_options                         *g:ale_hack_hackfmt_options*
+                                                   *b:ale_hack_hackfmt_options*
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to pass additional options to the hackfmt fixer.
+
+
+===============================================================================
+hhast                                                          *ale-hack-hhast*
+
+g:ale_hack_hhast_executable                       *g:ale_hack_hhast_executable*
+                                                  *b:ale_hack_hhast_executable*
+
+  Type: |String|
+  Default: `'vendor/bin/hhast-lint'`
+
+  This variable can be set to use a specific executable to interact with the
+  Hack typechecker.
+
+
+===============================================================================
+  vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:
diff --git a/doc/ale-php.txt b/doc/ale-php.txt
index 33796f7c..ba53db89 100644
--- a/doc/ale-php.txt
+++ b/doc/ale-php.txt
@@ -1,24 +1,6 @@
 ===============================================================================
 ALE PHP Integration                                           *ale-php-options*
 
-
-===============================================================================
-hack                                                             *ale-php-hack*
-
-There are no options for this linter.
-
-
-===============================================================================
-hackfmt                                                       *ale-php-hackfmt*
-
-g:ale_php_hackfmt_options                           *g:ale_php_hackfmt_options*
-                                                    *b:ale_php_hackfmt_options*
-  Type: |String|
-  Default: `''`
-
-  This variable can be set to pass additional options to the hackfmt fixer.
-
-
 ===============================================================================
 langserver                                                 *ale-php-langserver*
 
diff --git a/doc/ale.txt b/doc/ale.txt
index d4b51850..b60c3da0 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -96,6 +96,10 @@ CONTENTS                                                         *ale-contents*
       eslint..............................|ale-graphql-eslint|
       gqlint..............................|ale-graphql-gqlint|
       prettier............................|ale-graphql-prettier|
+    hack..................................|ale-hack-options|
+      hack................................|ale-hack-hack|
+      hackfmt.............................|ale-hack-hackfmt|
+      hhast...............................|ale-hack-hhast|
     handlebars............................|ale-handlebars-options|
       ember-template-lint.................|ale-handlebars-embertemplatelint|
     haskell...............................|ale-haskell-options|
@@ -171,8 +175,6 @@ CONTENTS                                                         *ale-contents*
       perlcritic..........................|ale-perl-perlcritic|
       perltidy............................|ale-perl-perltidy|
     php...................................|ale-php-options|
-      hack................................|ale-php-hack|
-      hackfmt.............................|ale-php-hackfmt|
       langserver..........................|ale-php-langserver|
       phan................................|ale-php-phan|
       phpcbf..............................|ale-php-phpcbf|
@@ -367,6 +369,7 @@ Notes:
 * GLSL: glslang, `glslls`
 * Go: `gofmt`, `goimports`, `go vet`!!, `golint`, `gotype`!!, `gometalinter`!!, `go build`!!, `gosimple`!!, `staticcheck`!!
 * GraphQL: `eslint`, `gqlint`, `prettier`
+* Hack: `hack`, `hackfmt`, `hhast`
 * Haml: `haml-lint`
 * Handlebars: `ember-template-lint`
 * Haskell: `brittany`, `ghc`, `cabal-ghc`, `stack-ghc`, `stack-build`!!, `ghc-mod`, `stack-ghc-mod`, `hlint`, `hdevtools`, `hfmt`
@@ -393,7 +396,7 @@ Notes:
 * Objective-C++: `clang`
 * OCaml: `merlin` (see |ale-ocaml-merlin|), `ols`
 * Perl: `perl -c`, `perl-critic`, `perltidy`
-* PHP: `hack`, `hackfmt`, `langserver`, `phan`, `php -l`, `phpcs`, `phpmd`, `phpstan`, `phpcbf`, `php-cs-fixer`
+* PHP: `langserver`, `phan`, `php -l`, `phpcs`, `phpmd`, `phpstan`, `phpcbf`, `php-cs-fixer`
 * PO: `alex`!!, `msgfmt`, `proselint`, `write-good`
 * Pod: `alex`!!, `proselint`, `write-good`
 * Pony: `ponyc`
diff --git a/test/fixers/test_hackfmt_fixer_callback.vader b/test/fixers/test_hackfmt_fixer_callback.vader
index ed78fc85..d294c15e 100644
--- a/test/fixers/test_hackfmt_fixer_callback.vader
+++ b/test/fixers/test_hackfmt_fixer_callback.vader
@@ -1,10 +1,10 @@
 Before:
-  Save g:ale_php_hackfmt_executable
-  Save g:ale_php_hackfmt_options
+  Save g:ale_hack_hackfmt_executable
+  Save g:ale_hack_hackfmt_options
 
   " Use an invalid global executable, so we don't match it.
-  let g:ale_php_hackfmt_executable = 'xxxinvalid'
-  let g:ale_php_hackfmt_options = ''
+  let g:ale_hack_hackfmt_executable = 'xxxinvalid'
+  let g:ale_hack_hackfmt_options = ''
 
   call ale#test#SetDirectory('/testplugin/test/fixers')
 
@@ -14,7 +14,7 @@ After:
   call ale#test#RestoreDirectory()
 
 Execute(The hackfmt callback should return the correct default values):
-  call ale#test#SetFilename('../hack_files/testfile.php')
+  call ale#test#SetFilename('../hack_files/testfile.hack')
 
   AssertEqual
   \ {
@@ -25,8 +25,8 @@ Execute(The hackfmt callback should return the correct default values):
   \ ale#fixers#hackfmt#Fix(bufnr(''))
 
 Execute(The hackfmt callback should include custom hackfmt options):
-  let g:ale_php_hackfmt_options = "--some-option"
-  call ale#test#SetFilename('../hack_files/testfile.php')
+  let g:ale_hack_hackfmt_options = "--some-option"
+  call ale#test#SetFilename('../hack_files/testfile.hack')
 
   AssertEqual
   \ {
diff --git a/test/hack_files/testfile.php b/test/hack_files/testfile.php
index e69de29b..313995d1 100644
--- a/test/hack_files/testfile.php
+++ b/test/hack_files/testfile.php
@@ -0,0 +1,4 @@
+<?hh // strict
+
+async function foo(): Awaitable<void> {
+}