Merge pull request #1849 from hsanson/1848-add-support-for-java-lsp

Add vscode-java-language-server linter

6 files changed, 78 insertions, 2 deletions

diff --git a/README.md b/README.md
index bd2ef92a..b7d9dd9c 100644
--- a/README.md
+++ b/README.md
@@ -132,7 +132,7 @@ formatting.
 | Haskell | [brittany](https://github.com/lspitzner/brittany), [ghc](https://www.haskell.org/ghc/), [cabal-ghc](https://www.haskell.org/cabal/), [stylish-haskell](https://github.com/jaspervdj/stylish-haskell), [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), [hie](https://github.com/haskell/haskell-ide-engine) |
 | HTML | [alex](https://github.com/wooorm/alex) !!, [HTMLHint](http://htmlhint.com/), [proselint](http://proselint.com/), [tidy](http://www.html-tidy.org/), [write-good](https://github.com/btford/write-good) |
 | Idris | [idris](http://www.idris-lang.org/) |
-| Java | [checkstyle](http://checkstyle.sourceforge.net), [javac](http://www.oracle.com/technetwork/java/javase/downloads/index.html), [google-java-format](https://github.com/google/google-java-format), [PMD](https://pmd.github.io/) |
+| Java | [checkstyle](http://checkstyle.sourceforge.net), [javac](http://www.oracle.com/technetwork/java/javase/downloads/index.html), [google-java-format](https://github.com/google/google-java-format), [PMD](https://pmd.github.io/), [javalsp](https://github.com/georgewfraser/vscode-javac) |
 | JavaScript | [eslint](http://eslint.org/), [flow](https://flowtype.org/), [jscs](http://jscs.info/), [jshint](http://jshint.com/), [prettier](https://github.com/prettier/prettier), [prettier-eslint](https://github.com/prettier/prettier-eslint-cli), [prettier-standard](https://github.com/sheerun/prettier-standard), [standard](http://standardjs.com/), [xo](https://github.com/sindresorhus/xo)
 | JSON | [fixjson](https://github.com/rhysd/fixjson), [jsonlint](http://zaa.ch/jsonlint/), [jq](https://stedolan.github.io/jq/), [prettier](https://github.com/prettier/prettier) |
 | Kotlin | [kotlinc](https://kotlinlang.org) !!, [ktlint](https://ktlint.github.io) !!, [languageserver](https://github.com/fwcd/KotlinLanguageServer) see `:help ale-integration-kotlin` for configuration instructions |
diff --git a/ale_linters/java/javalsp.vim b/ale_linters/java/javalsp.vim
new file mode 100644
index 00000000..f335e83c
--- /dev/null
+++ b/ale_linters/java/javalsp.vim
@@ -0,0 +1,22 @@
+" Author: Horacio Sanson <https://github.com/hsanson>
+" Description: Support for the Java language server https://github.com/georgewfraser/vscode-javac
+
+call ale#Set('java_javalsp_jar', 'javacs.jar')
+
+function! ale_linters#java#javalsp#Executable(buffer) abort
+    return 'java'
+endfunction
+
+function! ale_linters#java#javalsp#Command(buffer) abort
+    let l:jar = ale#Var(a:buffer, 'java_javalsp_jar')
+    return ale#Escape('java -cp ' . l:jar . ' -Xverify:none org.javacs.Main')
+endfunction
+
+call ale#linter#Define('java', {
+\   'name': 'javalsp',
+\   'lsp': 'stdio',
+\   'executable_callback': 'ale_linters#java#javalsp#Executable',
+\   'command_callback': 'ale_linters#java#javalsp#Command',
+\   'language': 'java',
+\   'project_root_callback': 'ale#java#FindProjectRoot',
+\})
diff --git a/autoload/ale/java.vim b/autoload/ale/java.vim
new file mode 100644
index 00000000..b7fd10bd
--- /dev/null
+++ b/autoload/ale/java.vim
@@ -0,0 +1,20 @@
+" Author: Horacio Sanson https://github.com/hsanson
+" Description: Functions for integrating with Java tools
+
+" Find the nearest dir contining a gradle or pom file and asume it
+" the root of a java app.
+function! ale#java#FindProjectRoot(buffer) abort
+    let l:gradle_root = ale#gradle#FindProjectRoot(a:buffer)
+
+    if !empty(l:gradle_root)
+        return l:gradle_root
+    endif
+
+    let l:maven_pom_file = ale#path#FindNearestFile(a:buffer, 'pom.xml')
+
+    if !empty(l:maven_pom_file)
+        return fnamemodify(l:maven_pom_file, ':h')
+    endif
+
+    return ''
+endfunction
diff --git a/doc/ale-java.txt b/doc/ale-java.txt
index 4481e823..827a268c 100644
--- a/doc/ale-java.txt
+++ b/doc/ale-java.txt
@@ -76,4 +76,27 @@ g:ale_java_pmd_options                                 *g:ale_java_pmd_options*
 
 
 ===============================================================================
+javalsp                                                      *ale-java-javalsp*
+
+To enable Java LSP linter you need to download and build the vscode-javac
+language server from https://github.com/georgewfraser/vscode-javac. Simply
+download the source code and then build the plugin using maven:
+
+   mvn package
+
+This generates a out/fat-jar.jar file that contains the language server. To
+let ALE use this language server you need to set the g:ale_java_javalsp_jar
+variable to the absolute path of this jar file.
+
+g:ale_java_javalsp_jar                                 *g:ale_java_javalsp_jar*
+                                                       *b:ale_java_javalsp_jar*
+
+  Type: String
+  Default: 'fat-jar.jar
+
+  Path to the location of the vscode-javac language server plugin.
+  and -d. They are added automatically.
+
+
+===============================================================================
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:
diff --git a/doc/ale.txt b/doc/ale.txt
index 8e126938..80d8b96c 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -127,6 +127,7 @@ CONTENTS                                                         *ale-contents*
       javac...............................|ale-java-javac|
       google-java-format..................|ale-java-google-java-format|
       pmd.................................|ale-java-pmd|
+      javalsp.............................|ale-java-javalsp|
     javascript............................|ale-javascript-options|
       eslint..............................|ale-javascript-eslint|
       flow................................|ale-javascript-flow|
@@ -388,7 +389,7 @@ Notes:
 * Haskell: `brittany`, `ghc`, `cabal-ghc`, `stylish-haskell`, `stack-ghc`, `stack-build`!!, `ghc-mod`, `stack-ghc-mod`, `hlint`, `hdevtools`, `hfmt`, `hie`
 * HTML: `alex`!!, `HTMLHint`, `proselint`, `tidy`, `write-good`
 * Idris: `idris`
-* Java: `checkstyle`, `javac`, `google-java-format`, `PMD`
+* Java: `checkstyle`, `javac`, `google-java-format`, `PMD`, `javalsp`
 * JavaScript: `eslint`, `flow`, `jscs`, `jshint`, `prettier`, `prettier-eslint`, `prettier-standard`, `standard`, `xo`
 * JSON: `fixjson`, `jsonlint`, `jq`, `prettier`
 * Kotlin: `kotlinc`!!, `ktlint`!!, `languageserver`
diff --git a/test/command_callback/test_javalsp_command_callback.vader b/test/command_callback/test_javalsp_command_callback.vader
new file mode 100644
index 00000000..1fbfddfb
--- /dev/null
+++ b/test/command_callback/test_javalsp_command_callback.vader
@@ -0,0 +1,10 @@
+
+Before:
+  call ale#assert#SetUpLinterTest('java', 'javalsp')
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(The javalsp callback should return the correct default value):
+  AssertLinter 'java', ale#Escape('java -cp javacs.jar -Xverify:none org.javacs.Main')
+