Close #5112 - Support newer Pyright and other LSPs

Add support for dynamic capability registration for the diagnostic
pull model to support Pyright >= 1.1.407 and other language servers.

This is a rather complex and intricate change tested with Pyright and
gopls, and may need further tweaking if something breaks with another
server.

test/lsp/test_engine_lsp_response_handling.vader

@@ -1,4 +1,6 @@
 Before:
+  runtime autoload/ale/lsp.vim
+
   Save g:ale_set_lists_synchronously
   Save g:ale_buffer_info
   Save g:ale_lsp_error_messages
@@ -40,6 +42,7 @@ After:
   call ale#test#RestoreDirectory()
   call ale#linter#Reset()
   call ale#lsp_linter#ClearLSPData()
+  call ale#lsp_linter#ClearDiagnosticURIMap()
 
 Given foobar(An empty file):
 Execute(tsserver syntax error responses should be handled correctly):
@@ -534,6 +537,60 @@ Execute(LSP pull model diagnostic responses that are 'unchanged' should be handl
   \ g:ale_buffer_info[bufnr('')].loclist
   AssertEqual [], g:ale_buffer_info[bufnr('')].active_linter_list
 
+Execute(LSP pull model diagnostic errors should clear pending requests):
+  let b:ale_linters = ['eclipselsp']
+  runtime ale_linters/java/eclipselsp.vim
+
+  if has('win32')
+    call ale#test#SetFilename('filename,[]^$.ts')
+  else
+    call ale#test#SetFilename('filename*?,{}[]^$.java')
+  endif
+
+  call ale#engine#InitBufferInfo(bufnr(''))
+  let g:ale_buffer_info[bufnr('')].loclist = [
+  \ {
+  \   'lnum': 1,
+  \   'bufnr': bufnr(''),
+  \   'col': 1,
+  \   'pattern': '',
+  \   'valid': 1,
+  \   'vcol': 0,
+  \   'nr': -1,
+  \   'type': 'W',
+  \   'text': 'Missing JRE 1-8'
+  \ },
+  \]
+
+  call ale#lsp_linter#SetLSPLinterMap({'1': {'name': 'eclipselsp', 'aliases': [], 'lsp': 'stdio'}})
+  call ale#lsp_linter#SetDiagnosticURIMap({'347': ale#util#ToURI(expand('%:p'))})
+
+  call ale#lsp_linter#HandleLSPResponse(1, {
+  \ 'jsonrpc': '2.0',
+  \ 'id': 347,
+  \ 'error': {
+  \   'code': -32802,
+  \   'message': 'server cancelled',
+  \ },
+  \})
+
+  AssertEqual {}, ale#lsp_linter#GetDiagnosticURIMap()
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 1,
+  \     'bufnr': bufnr(''),
+  \     'col': 1,
+  \     'pattern': '',
+  \     'valid': 1,
+  \     'vcol': 0,
+  \     'nr': -1,
+  \     'type': 'W',
+  \     'text': 'Missing JRE 1-8'
+  \    }
+  \ ],
+  \ g:ale_buffer_info[bufnr('')].loclist
+
 Execute(workspace/configuration requests should be answered with the connection config):
   let g:sent_responses = []
 
@@ -564,26 +621,134 @@ Execute(workspace/configuration requests should be answered with the connection
 
 Execute(client/registerCapability requests should be acknowledged):
   let g:sent_responses = []
+  let g:registered_capabilities = []
+  let g:sent_pull_diagnostics = []
 
   function! ale#lsp#SendResponse(conn_id, id, result) abort
     call add(g:sent_responses, [a:conn_id, a:id, a:result])
   endfunction
 
+  function! ale#lsp#RegisterCapabilities(conn_id, registrations) abort
+    call add(g:registered_capabilities, [a:conn_id, a:registrations])
+
+    return 1
+  endfunction
+
+  function! ale#lsp#SendDiagnosticsForOpenDocuments(conn_id) abort
+    call add(g:sent_pull_diagnostics, a:conn_id)
+
+    return []
+  endfunction
+
   call ale#lsp_linter#SetLSPLinterMap({'1': {'name': 'expert', 'aliases': [], 'lsp': 'stdio'}})
   call ale#lsp_linter#HandleLSPResponse(1, {
   \ 'jsonrpc': '2.0',
   \ 'id': 12,
   \ 'method': 'client/registerCapability',
   \ 'params': {
-  \   'registrations': [{'id': 'abc', 'method': 'textDocument/didSave'}],
+  \   'registrations': [
+  \     {
+  \       'id': 'abc',
+  \       'method': 'textDocument/diagnostic',
+  \       'registerOptions': {'interFileDependencies': v:true},
+  \     },
+  \   ],
   \ },
   \})
 
   AssertEqual
   \ [[1, 12, v:null]],
   \ g:sent_responses
+  AssertEqual
+  \ [[1, [
+  \   {
+  \     'id': 'abc',
+  \     'method': 'textDocument/diagnostic',
+  \     'registerOptions': {'interFileDependencies': v:true},
+  \   },
+  \ ]]],
+  \ g:registered_capabilities
+  AssertEqual [1], g:sent_pull_diagnostics
 
   unlet! g:sent_responses
+  unlet! g:registered_capabilities
+  unlet! g:sent_pull_diagnostics
+  runtime autoload/ale/lsp.vim
+
+Execute(workspace/diagnostic/refresh requests should pull diagnostics):
+  let g:sent_responses = []
+  let g:sent_pull_diagnostics = []
+
+  function! ale#lsp#SendResponse(conn_id, id, result) abort
+    call add(g:sent_responses, [a:conn_id, a:id, a:result])
+  endfunction
+
+  function! ale#lsp#SendDiagnosticsForOpenDocuments(conn_id) abort
+    call add(g:sent_pull_diagnostics, a:conn_id)
+
+    return []
+  endfunction
+
+  call ale#lsp_linter#SetLSPLinterMap({'1': {'name': 'expert', 'aliases': [], 'lsp': 'stdio'}})
+  call ale#lsp_linter#SetDiagnosticURIMap({'13': 'file://foo.py'})
+
+  call ale#lsp_linter#HandleLSPResponse(1, {
+  \ 'jsonrpc': '2.0',
+  \ 'id': 13,
+  \ 'method': 'workspace/diagnostic/refresh',
+  \})
+
+  AssertEqual
+  \ [[1, 13, v:null]],
+  \ g:sent_responses
+  AssertEqual [1], g:sent_pull_diagnostics
+  AssertEqual {'13': 'file://foo.py'}, ale#lsp_linter#GetDiagnosticURIMap()
+
+  unlet! g:sent_responses
+  unlet! g:sent_pull_diagnostics
+  runtime autoload/ale/lsp.vim
+
+Execute(client/unregisterCapability requests should unregister and be acknowledged):
+  let g:sent_responses = []
+  let g:unregistered_capabilities = []
+
+  function! ale#lsp#SendResponse(conn_id, id, result) abort
+    call add(g:sent_responses, [a:conn_id, a:id, a:result])
+  endfunction
+
+  function! ale#lsp#UnregisterCapabilities(conn_id, unregisterations) abort
+    call add(g:unregistered_capabilities, [a:conn_id, a:unregisterations])
+
+    return 1
+  endfunction
+
+  call ale#lsp_linter#SetLSPLinterMap({'1': {'name': 'expert', 'aliases': [], 'lsp': 'stdio'}})
+  call ale#lsp_linter#SetDiagnosticURIMap({'14': 'file://foo.py'})
+
+  call ale#lsp_linter#HandleLSPResponse(1, {
+  \ 'jsonrpc': '2.0',
+  \ 'id': 14,
+  \ 'method': 'client/unregisterCapability',
+  \ 'params': {
+  \   'unregisterations': [
+  \     {
+  \       'id': 'abc',
+  \       'method': 'textDocument/diagnostic',
+  \     },
+  \   ],
+  \ },
+  \})
+
+  AssertEqual
+  \ [[1, 14, v:null]],
+  \ g:sent_responses
+  AssertEqual
+  \ [[1, [{'id': 'abc', 'method': 'textDocument/diagnostic'}]]],
+  \ g:unregistered_capabilities
+  AssertEqual {'14': 'file://foo.py'}, ale#lsp_linter#GetDiagnosticURIMap()
+
+  unlet! g:sent_responses
+  unlet! g:unregistered_capabilities
   runtime autoload/ale/lsp.vim
 
 Execute(LSP errors should be logged in the history):