Kotlin and general Gradle support. (#745)

ale_linters/kotlin/kotlinc.vim

@@ -12,17 +12,21 @@ let g:ale_kotlin_kotlinc_module_filename = get(g:, 'ale_kotlin_kotlinc_module_fi
 let s:classpath_sep = has('unix') ? ':' : ';'
 
 function! ale_linters#kotlin#kotlinc#GetImportPaths(buffer) abort
-    " exec maven only if classpath is not set
+    " exec maven/gradle only if classpath is not set
     if ale#Var(a:buffer, 'kotlin_kotlinc_classpath') !=# ''
         return ''
     else
         let l:pom_path = ale#path#FindNearestFile(a:buffer, 'pom.xml')
-
         if !empty(l:pom_path) && executable('mvn')
             return ale#path#CdString(fnamemodify(l:pom_path, ':h'))
                         \ . 'mvn dependency:build-classpath'
         endif
 
+        let l:classpath_command = ale#gradle#BuildClasspathCommand(a:buffer)
+        if !empty(l:classpath_command)
+            return l:classpath_command
+        endif
+
         return ''
     endif
 endfunction
@@ -69,7 +73,7 @@ function! ale_linters#kotlin#kotlinc#GetCommand(buffer, import_paths) abort
     if ale#Var(a:buffer, 'kotlin_kotlinc_classpath') !=# ''
         let l:kotlinc_opts .= ' -cp ' . ale#Var(a:buffer, 'kotlin_kotlinc_classpath')
     else
-        " get classpath from maven
+        " get classpath from maven/gradle
         let l:kotlinc_opts .= s:BuildClassPathOption(a:buffer, a:import_paths)
     endif
 
@@ -78,7 +82,15 @@ function! ale_linters#kotlin#kotlinc#GetCommand(buffer, import_paths) abort
         let l:fname .= expand(ale#Var(a:buffer, 'kotlin_kotlinc_sourcepath'), 1) . ' '
     else
         " Find the src directory for files in this project.
-        let l:src_dir = ale#path#FindNearestDirectory(a:buffer, 'src/main/java')
+
+        let l:project_root = ale#gradle#FindProjectRoot(a:buffer)
+        if !empty(l:project_root)
+            let l:src_dir = l:project_root
+        else
+            let l:src_dir = ale#path#FindNearestDirectory(a:buffer, 'src/main/java')
+            \   . ' ' . ale#path#FindNearestDirectory(a:buffer, 'src/main/kotlin')
+        endif
+
         let l:fname .= expand(l:src_dir, 1) . ' '
     endif
     let l:fname .= ale#Escape(expand('#' . a:buffer . ':p'))
@@ -155,3 +167,4 @@ call ale#linter#Define('kotlin', {
 \   'callback': 'ale_linters#kotlin#kotlinc#Handle',
 \   'lint_file': 1,
 \})
+

autoload/ale/gradle.vim

@@ -0,0 +1,54 @@
+" Author: Michael Pardo <michael@michaelpardo.com>
+" Description: Functions for working with Gradle projects.
+
+let s:script_path = fnamemodify(resolve(expand('<sfile>:p')), ':h')
+
+" Given a buffer number, find a Gradle project root.
+function! ale#gradle#FindProjectRoot(buffer) abort
+    let l:gradlew_path = ale#path#FindNearestFile(a:buffer, 'gradlew')
+    if !empty(l:gradlew_path)
+        return fnamemodify(l:gradlew_path, ':h')
+    endif
+
+    let l:settings_path = ale#path#FindNearestFile(a:buffer, 'settings.gradle')
+    if !empty(l:settings_path)
+        return fnamemodify(l:settings_path, ':h')
+    endif
+
+    let l:build_path = ale#path#FindNearestFile(a:buffer, 'build.gradle')
+    if !empty(l:build_path)
+        return fnamemodify(l:build_path, ':h')
+    endif
+
+    return ''
+endfunction
+
+" Given a buffer number, find the path to the executable.
+" First search on the path for 'gradlew', if nothing is found, try the global
+" command. Returns an empty string if cannot find the executable.
+function! ale#gradle#FindExecutable(buffer) abort
+    let l:gradlew_path = ale#path#FindNearestFile(a:buffer, 'gradlew')
+    if !empty(l:gradlew_path)
+        return l:gradlew_path
+    endif
+
+    if executable('gradle')
+        return 'gradle'
+    endif
+
+    return ''
+endfunction
+
+" Given a buffer number, build a command to print the classpath of the root
+" project. Returns an empty string if cannot build the command.
+function! ale#gradle#BuildClasspathCommand(buffer) abort
+    let l:executable = ale#gradle#FindExecutable(a:buffer)
+    let l:project_root = ale#gradle#FindProjectRoot(a:buffer)
+
+    if !empty(l:executable) && !empty(l:project_root)
+        return ale#path#CdString(l:project_root)
+        \   . l:executable . ' -I ' . s:script_path . '/gradle/init.gradle -q printClasspath'
+    endif
+
+    return ''
+endfunction

autoload/ale/gradle/init.gradle

@@ -0,0 +1,23 @@
+class ClasspathPlugin implements Plugin<Project> {
+    void apply(Project project) {
+        project.task('printClasspath') {
+            doLast {
+                project
+                    .rootProject
+                    .allprojects
+                    .configurations
+                    .flatten()
+                    .findAll { it.name.endsWith('Classpath') }
+                    .collect { it.resolve() }
+                    .flatten()
+                    .unique()
+                    .findAll { it.exists() }
+                    .each { println it }
+            }
+        }
+    }
+}
+
+rootProject {
+    apply plugin: ClasspathPlugin
+}

test/test_gradle_build_classpath_command.vader

@@ -0,0 +1,42 @@
+Before:
+  call ale#test#SetDirectory('/testplugin/test')
+  runtime ale_linters/kotlin/kotlinc.vim
+  let g:ale_gradle_path = $PATH
+
+After:
+  call ale#test#RestoreDirectory()
+  call ale#linter#Reset()
+  let $PATH = g:ale_gradle_path
+
+Execute(Should return 'gradlew' command if project includes gradle wapper):
+  call ale#test#SetFilename('gradle-test-files/wrapped-project/src/main/kotlin/dummy.kt')
+
+  let g:project_root = '/testplugin/test/gradle-test-files/wrapped-project'
+  let g:gradle_executable = '/testplugin/test/gradle-test-files/wrapped-project/gradlew'
+  let g:gradle_init_path = '/testplugin/autoload/ale/gradle/init.gradle'
+  let g:gradle_options = '-I ' . g:gradle_init_path . ' -q printClasspath'
+
+
+  AssertEqual
+  \ "cd '" . g:project_root . "' && " . g:gradle_executable . " " . g:gradle_options,
+  \ ale#gradle#BuildClasspathCommand(bufnr(''))
+
+Execute(Should return 'gradle' command if project does not include gradle wapper):
+  call ale#test#SetFilename('gradle-test-files/unwrapped-project/src/main/kotlin/dummy.kt')
+  let $PATH .= ':' . g:dir . '/gradle-test-files'
+
+  let g:project_root = '/testplugin/test/gradle-test-files/unwrapped-project'
+  let g:gradle_executable = 'gradle'
+  let g:gradle_init_path = '/testplugin/autoload/ale/gradle/init.gradle'
+  let g:gradle_options = '-I ' . g:gradle_init_path . ' -q printClasspath'
+
+  AssertEqual
+  \ "cd '" . g:project_root . "' && " . g:gradle_executable . " " . g:gradle_options,
+  \ ale#gradle#BuildClasspathCommand(bufnr(''))
+
+Execute(Should return empty string if gradle cannot be executed):
+  call ale#test#SetFilename('gradle-test-files/non-gradle-project/src/main/kotlin/dummy.kt')
+
+  AssertEqual
+  \ '',
+  \ ale#gradle#BuildClasspathCommand(bufnr(''))

test/test_gradle_find_executable.vader

@@ -0,0 +1,31 @@
+Before:
+  call ale#test#SetDirectory('/testplugin/test')
+  runtime ale_linters/kotlin/kotlinc.vim
+  let g:ale_gradle_path = $PATH
+
+After:
+  call ale#test#RestoreDirectory()
+  call ale#linter#Reset()
+  let $PATH = g:ale_gradle_path
+  
+Execute(Should return 'gradlew' if found in parent directory):
+  call ale#test#SetFilename('gradle-test-files/wrapped-project/src/main/kotlin/dummy.kt')
+
+  AssertEqual
+  \ g:dir . '/gradle-test-files/wrapped-project/gradlew',
+  \ ale#gradle#FindExecutable(bufnr(''))
+
+Execute(Should return 'gradle' if 'gradlew' not found in parent directory):
+  call ale#test#SetFilename('gradle-test-files/unwrapped-project/src/main/kotlin/dummy.kt')
+  let $PATH .= ':' . g:dir . '/gradle-test-files'
+  
+  AssertEqual
+  \ 'gradle', 
+  \ ale#gradle#FindExecutable(bufnr(''))
+
+Execute(Should return empty string if 'gradlew' not in parent directory and gradle not in path):
+  call ale#test#SetFilename('gradle-test-files/unwrapped-project/src/main/kotlin/dummy.kt')
+  
+  AssertEqual
+  \ '', 
+  \ ale#gradle#FindExecutable(bufnr(''))

test/test_gradle_find_project_root.vader

@@ -0,0 +1,35 @@
+Before:
+  call ale#test#SetDirectory('/testplugin/test')
+  runtime ale_linters/kotlin/kotlinc.vim
+
+After:
+  call ale#test#RestoreDirectory()
+  call ale#linter#Reset()
+
+Execute(Should return directory for 'gradlew' if found in parent directory):
+  call ale#test#SetFilename('gradle-test-files/wrapped-project/src/main/kotlin/dummy.kt')
+
+  AssertEqual
+  \ g:dir . '/gradle-test-files/wrapped-project',
+  \ ale#gradle#FindProjectRoot(bufnr(''))
+
+Execute(Should return directory for 'settings.gradle' if found in parent directory):
+  call ale#test#SetFilename('gradle-test-files/settings-gradle-project/src/main/kotlin/dummy.kt')
+
+  AssertEqual
+  \ g:dir . '/gradle-test-files/settings-gradle-project',
+  \ ale#gradle#FindProjectRoot(bufnr(''))
+
+Execute(Should return directory for 'build.gradle' if found in parent directory):
+  call ale#test#SetFilename('gradle-test-files/build-gradle-project/src/main/kotlin/dummy.kt')
+
+  AssertEqual
+  \ g:dir . '/gradle-test-files/build-gradle-project',
+  \ ale#gradle#FindProjectRoot(bufnr(''))
+
+Execute(Should return empty string if gradle files are not found in parent directory):
+  call ale#test#SetFilename('gradle-test-files/non-gradle-project/src/main/kotlin/dummy.kt')
+
+  AssertEqual
+  \ '',
+  \ ale#gradle#FindProjectRoot(bufnr(''))