Close #1521 - Allow the language to be set with simple strings for LSP linters

11 files changed, 65 insertions, 45 deletions

diff --git a/ale_linters/dart/language_server.vim b/ale_linters/dart/language_server.vim
index 15c77017..bed77c52 100644
--- a/ale_linters/dart/language_server.vim
+++ b/ale_linters/dart/language_server.vim
@@ -7,10 +7,6 @@ function! ale_linters#dart#language_server#GetExecutable(buffer) abort
     return ale#Var(a:buffer, 'dart_language_server_executable')
 endfunction
 
-function! ale_linters#dart#language_server#GetLanguage(buffer) abort
-    return 'dart'
-endfunction
-
 function! ale_linters#dart#language_server#GetProjectRoot(buffer) abort
     " Note: pub only looks for pubspec.yaml, there's no point in adding
     " support for pubspec.yml
@@ -24,7 +20,6 @@ call ale#linter#Define('dart', {
 \   'lsp': 'stdio',
 \   'executable_callback': 'ale_linters#dart#language_server#GetExecutable',
 \   'command_callback': 'ale_linters#dart#language_server#GetExecutable',
-\   'language_callback': 'ale_linters#dart#language_server#GetLanguage',
+\   'language': 'dart',
 \   'project_root_callback': 'ale_linters#dart#language_server#GetProjectRoot',
 \})
-
diff --git a/ale_linters/glsl/glslls.vim b/ale_linters/glsl/glslls.vim
index 67ea379c..c19f28c2 100644
--- a/ale_linters/glsl/glslls.vim
+++ b/ale_linters/glsl/glslls.vim
@@ -18,10 +18,6 @@ function! ale_linters#glsl#glslls#GetCommand(buffer) abort
     return ale#Escape(l:executable) . l:logfile_args . ' --stdin'
 endfunction
 
-function! ale_linters#glsl#glslls#GetLanguage(buffer) abort
-    return 'glsl'
-endfunction
-
 function! ale_linters#glsl#glslls#GetProjectRoot(buffer) abort
     let l:project_root = ale#c#FindProjectRoot(a:buffer)
 
@@ -33,6 +29,6 @@ call ale#linter#Define('glsl', {
 \   'lsp': 'stdio',
 \   'executable_callback': 'ale_linters#glsl#glslls#GetExecutable',
 \   'command_callback': 'ale_linters#glsl#glslls#GetCommand',
-\   'language_callback': 'ale_linters#glsl#glslls#GetLanguage',
+\   'language': 'glsl',
 \   'project_root_callback': 'ale_linters#glsl#glslls#GetProjectRoot',
 \})
diff --git a/ale_linters/php/langserver.vim b/ale_linters/php/langserver.vim
index 7e1321f9..0f3ead66 100644
--- a/ale_linters/php/langserver.vim
+++ b/ale_linters/php/langserver.vim
@@ -14,10 +14,6 @@ function! ale_linters#php#langserver#GetCommand(buffer) abort
     return 'php ' . ale#Escape(ale_linters#php#langserver#GetExecutable(a:buffer))
 endfunction
 
-function! ale_linters#php#langserver#GetLanguage(buffer) abort
-    return 'php'
-endfunction
-
 function! ale_linters#php#langserver#GetProjectRoot(buffer) abort
     let l:git_path = ale#path#FindNearestDirectory(a:buffer, '.git')
 
@@ -29,6 +25,6 @@ call ale#linter#Define('php', {
 \   'lsp': 'stdio',
 \   'executable_callback': 'ale_linters#php#langserver#GetExecutable',
 \   'command_callback': 'ale_linters#php#langserver#GetCommand',
-\   'language_callback': 'ale_linters#php#langserver#GetLanguage',
+\   'language': 'php',
 \   'project_root_callback': 'ale_linters#php#langserver#GetProjectRoot',
 \})
diff --git a/ale_linters/python/pyls.vim b/ale_linters/python/pyls.vim
index 09f31ec6..883b38f5 100644
--- a/ale_linters/python/pyls.vim
+++ b/ale_linters/python/pyls.vim
@@ -14,16 +14,12 @@ function! ale_linters#python#pyls#GetCommand(buffer) abort
     return ale#Escape(l:executable)
 endfunction
 
-function! ale_linters#python#pyls#GetLanguage(buffer) abort
-    return 'python'
-endfunction
-
 call ale#linter#Define('python', {
 \   'name': 'pyls',
 \   'lsp': 'stdio',
 \   'executable_callback': 'ale_linters#python#pyls#GetExecutable',
 \   'command_callback': 'ale_linters#python#pyls#GetCommand',
-\   'language_callback': 'ale_linters#python#pyls#GetLanguage',
+\   'language': 'python',
 \   'project_root_callback': 'ale#python#FindProjectRoot',
 \   'completion_filter': 'ale#completion#python#CompletionItemFilter',
 \})
diff --git a/ale_linters/rust/rls.vim b/ale_linters/rust/rls.vim
index 24316b04..d5160b14 100644
--- a/ale_linters/rust/rls.vim
+++ b/ale_linters/rust/rls.vim
@@ -19,10 +19,6 @@ function! ale_linters#rust#rls#GetCommand(buffer) abort
     endif
 endfunction
 
-function! ale_linters#rust#rls#GetLanguage(buffer) abort
-    return 'rust'
-endfunction
-
 function! ale_linters#rust#rls#GetProjectRoot(buffer) abort
     let l:cargo_file = ale#path#FindNearestFile(a:buffer, 'Cargo.toml')
 
@@ -34,6 +30,6 @@ call ale#linter#Define('rust', {
 \   'lsp': 'stdio',
 \   'executable_callback': 'ale_linters#rust#rls#GetExecutable',
 \   'command_callback': 'ale_linters#rust#rls#GetCommand',
-\   'language_callback': 'ale_linters#rust#rls#GetLanguage',
+\   'language': 'rust',
 \   'project_root_callback': 'ale_linters#rust#rls#GetProjectRoot',
 \})
diff --git a/ale_linters/typescript/tsserver.vim b/ale_linters/typescript/tsserver.vim
index 5eb77dad..08bd0f41 100644
--- a/ale_linters/typescript/tsserver.vim
+++ b/ale_linters/typescript/tsserver.vim
@@ -10,10 +10,6 @@ function! ale_linters#typescript#tsserver#GetProjectRoot(buffer) abort
     return ''
 endfunction
 
-function! ale_linters#typescript#tsserver#GetLanguage(buffer) abort
-    return ''
-endfunction
-
 function! ale_linters#typescript#tsserver#GetExecutable(buffer) abort
     return ale#node#FindExecutable(a:buffer, 'typescript_tsserver', [
     \   'node_modules/.bin/tsserver',
@@ -26,5 +22,5 @@ call ale#linter#Define('typescript', {
 \   'executable_callback': 'ale_linters#typescript#tsserver#GetExecutable',
 \   'command_callback': 'ale_linters#typescript#tsserver#GetExecutable',
 \   'project_root_callback': 'ale_linters#typescript#tsserver#GetProjectRoot',
-\   'language_callback': 'ale_linters#typescript#tsserver#GetLanguage',
+\   'language': '',
 \})
diff --git a/autoload/ale/linter.vim b/autoload/ale/linter.vim
index 8aec2598..1e0ec304 100644
--- a/autoload/ale/linter.vim
+++ b/autoload/ale/linter.vim
@@ -51,6 +51,10 @@ function! s:IsBoolean(value) abort
     return type(a:value) == type(0) && (a:value == 0 || a:value == 1)
 endfunction
 
+function! s:LanguageGetter(buffer) dict abort
+    return l:self.language
+endfunction
+
 function! ale#linter#PreProcess(linter) abort
     if type(a:linter) != type({})
         throw 'The linter object must be a Dictionary'
@@ -185,10 +189,26 @@ function! ale#linter#PreProcess(linter) abort
     endif
 
     if l:needs_lsp_details
-        let l:obj.language_callback = get(a:linter, 'language_callback')
+        if has_key(a:linter, 'language')
+            if has_key(a:linter, 'language_callback')
+                throw 'Only one of `language` or `language_callback` '
+                \   . 'should be set'
+            endif
+
+            let l:obj.language = get(a:linter, 'language')
 
-        if !s:IsCallback(l:obj.language_callback)
-            throw '`language_callback` must be a callback for LSP linters'
+            if type(l:obj.language) != type('')
+                throw '`language` must be a string'
+            endif
+
+            " Make 'language_callback' return the 'language' value.
+            let l:obj.language_callback = function('s:LanguageGetter')
+        else
+            let l:obj.language_callback = get(a:linter, 'language_callback')
+
+            if !s:IsCallback(l:obj.language_callback)
+                throw '`language_callback` must be a callback for LSP linters'
+            endif
         endif
 
         let l:obj.project_root_callback = get(a:linter, 'project_root_callback')
diff --git a/doc/ale.txt b/doc/ale.txt
index de6507e3..ca15048a 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -2272,9 +2272,9 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          process for a language server runnning, and
                          communicates with it directly via a |channel|.
 
-                         When this argument is not empty, then the
-                         `project_callback` and `language_callback` arguments
-                         must also be defined.
+                         When this argument is not empty, `project_callback`
+                         must be defined, and only one of either `language` or
+                         `language_callback` must be defined.
 
                          LSP linters handle diagnostics automatically, so
                          the `callback` argument must not be defined.
@@ -2289,13 +2289,20 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          This argument must only be set if the `lsp` argument
                          is also set to a non-empty string.
 
+  `language`               A |String| representing the name of the language
+                         being checked. This string will be sent to the LSP to
+                         tell it what type of language is being checked.
+
+                         This argument must only be set if the `lsp` argument
+                         is also set to a non-empty string.
+
   `language_callback`      A |String| or |Funcref| for a callback function
                          accepting a buffer number. A |String| should be
                          returned representing the name of the language being
                          checked.
 
-                         This argument must only be set if the `lsp` argument
-                         is also set to a non-empty string.
+                         This option can be used instead of `language` if a
+                         linter can check multiple languages.
 
   `aliases`                A |List| of aliases for the linter name.
 
diff --git a/test/command_callback/test_php_langserver_callbacks.vader b/test/command_callback/test_php_langserver_callbacks.vader
index 0dc30630..ebcae0e7 100644
--- a/test/command_callback/test_php_langserver_callbacks.vader
+++ b/test/command_callback/test_php_langserver_callbacks.vader
@@ -42,9 +42,6 @@ Execute(Vendor executables should be detected):
   \ )),
   \ ale_linters#php#langserver#GetCommand(bufnr(''))
 
-Execute(The language string should be correct):
-  AssertEqual 'php', ale_linters#php#langserver#GetLanguage(bufnr(''))
-
 Execute(The project path should be correct for .git directories):
   call ale#test#SetFilename('php-langserver-project/test.php')
   call mkdir(g:dir . '/.git')
diff --git a/test/command_callback/test_rust_rls_callbacks.vader b/test/command_callback/test_rust_rls_callbacks.vader
index d537bccb..16bde98a 100644
--- a/test/command_callback/test_rust_rls_callbacks.vader
+++ b/test/command_callback/test_rust_rls_callbacks.vader
@@ -35,9 +35,6 @@ Execute(The toolchain should be ommitted if not given):
   \ ale#Escape('rls'),
   \ ale_linters#rust#rls#GetCommand(bufnr(''))
 
-Execute(The language string should be correct):
-  AssertEqual 'rust', ale_linters#rust#rls#GetLanguage(bufnr(''))
-
 Execute(The project root should be detected correctly):
   AssertEqual '', ale_linters#rust#rls#GetProjectRoot(bufnr(''))
 
diff --git a/test/test_linter_defintion_processing.vader b/test/test_linter_defintion_processing.vader
index d946a600..653587b6 100644
--- a/test/test_linter_defintion_processing.vader
+++ b/test/test_linter_defintion_processing.vader
@@ -421,6 +421,30 @@ Execute(PreProcess should accept LSP server configurations):
 
   AssertEqual 'socket', ale#linter#PreProcess(g:linter).lsp
 
+Execute(PreProcess should accept let you specify the language as just a string):
+  let g:linter = {
+  \ 'name': 'x',
+  \ 'lsp': 'socket',
+  \ 'address_callback': 'X',
+  \ 'language': 'foobar',
+  \ 'project_root_callback': 'x',
+  \}
+
+  AssertEqual 'foobar', ale#linter#PreProcess(g:linter).language_callback(0)
+
+Execute(PreProcess should complain about using language and language_callback together):
+  let g:linter = {
+  \ 'name': 'x',
+  \ 'lsp': 'socket',
+  \ 'address_callback': 'X',
+  \ 'language': 'x',
+  \ 'language_callback': 'x',
+  \ 'project_root_callback': 'x',
+  \}
+
+  AssertThrows call ale#linter#PreProcess(g:linter)
+  AssertEqual 'Only one of `language` or `language_callback` should be set', g:vader_exception
+
 Execute(PreProcess should require an address_callback for LSP socket configurations):
   let g:linter = {
   \ 'name': 'x',