gopls: add go_gopls_init_options

ale_linters/go/gopls.vim

@@ -4,6 +4,7 @@
 
 call ale#Set('go_gopls_executable', 'gopls')
 call ale#Set('go_gopls_options', '--mode stdio')
+call ale#Set('go_gopls_init_options', {})
 
 function! ale_linters#go#gopls#GetCommand(buffer) abort
     return ale#go#EnvString(a:buffer)
@@ -31,4 +32,5 @@ call ale#linter#Define('go', {
 \   'executable': {b -> ale#Var(b, 'go_gopls_executable')},
 \   'command': function('ale_linters#go#gopls#GetCommand'),
 \   'project_root': function('ale_linters#go#gopls#FindProjectRoot'),
+\   'initialization_options': {b -> ale#Var(b, 'go_gopls_init_options')},
 \})

doc/ale-go.txt

@@ -207,6 +207,27 @@ g:ale_go_gopls_options                                 *g:ale_go_gopls_options*
   Type: |String|
   Default: `''`
 
+  Command-line options passed to the gopls executable. See `gopls -h`.
+
+
+g:ale_go_gopls_init_options                       *g:ale_go_gopls_init_options*
+                                                  *b:ale_go_gopls_init_options*
+  Type: |Dictionary|
+  Default: `{}`
+
+  LSP initialization options passed to gopls. This can be used to configure
+  the behaviour of gopls.
+
+  Example: >
+  let g:ale_go_gopls_init_options = {'ui.diagnostic.analyses': {
+        \ 'composites': v:false,
+        \ 'unusedparams': v:true,
+        \ 'unusedresult': v:true,
+        \ }}
+<
+
+  For a full list of supported analyzers, see:
+  https://github.com/golang/tools/blob/master/gopls/doc/analyzers.md
 
 ===============================================================================
 govet                                                            *ale-go-govet*

test/command_callback/test_gopls_command_callback.vader

@@ -36,6 +36,9 @@ Execute(should set gopls options):
   AssertLinter 'gopls',
   \ ale#Escape('gopls') . ' --mode stdio --trace'
 
+  let b:ale_go_gopls_init_options = {'ui.diagnostic.analyses': {'composites': v:false}}
+  AssertLSPOptions {'ui.diagnostic.analyses': {'composites': v:false}}
+
 Execute(should support go environment variables):
   let b:ale_go_go111module = 'off'