Before:
  runtime autoload/ale/lsp.vim

  let g:message_list = []

  function! MarkAllConnectionsInitialized() abort
    for l:conn in values(ale#lsp#GetConnections())
      let l:conn.initialized = 1
    endfor
  endfunction

  function! MarkDocumentOpened() abort
    for l:conn in values(ale#lsp#GetConnections())
      let l:conn.open_documents[bufnr('')] = 1
    endfor
  endfunction

  function! ale#lsp#Send(conn_id, message) abort
    let l:connections = ale#lsp#GetConnections()

    if !l:connections[a:conn_id].initialized
        throw 'LSP server not initialized yet!'
    endif

    call add(g:message_list, [a:conn_id] + a:message)
  endfunction

  call ale#lsp#ResetConnections()

After:
  unlet! g:message_list
  delfunction MarkAllConnectionsInitialized
  delfunction MarkDocumentOpened

  call ale#lsp#ResetConnections()

  runtime autoload/ale/lsp.vim

Execute(No errors should be thrown if the connection is not initialized):
  call ale#lsp#Register('command', '/foo', {})
  call MarkDocumentOpened()

  call ale#engine#Cleanup(bufnr(''))
  AssertEqual [], g:message_list

Execute(No messages should be sent if the document wasn't opened):
  call ale#lsp#Register('command', '/foo', {})
  call MarkAllConnectionsInitialized()

  call ale#engine#Cleanup(bufnr(''))
  AssertEqual [], g:message_list

Execute(A message should be sent if the document was opened):
  call ale#lsp#Register('command', '/foo', {})
  call MarkAllConnectionsInitialized()

  call ale#lsp#OpenDocument('command:/foo', bufnr(''), 'lang')
  call ale#engine#Cleanup(bufnr(''))
  " We should only send the message once.
  call ale#engine#Cleanup(bufnr(''))

  AssertEqual
  \ [
  \   ['command:/foo', 1, 'textDocument/didOpen', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \       'version': g:ale_lsp_next_version_id - 1,
  \       'languageId': 'lang',
  \       'text': "\n",
  \     },
  \   }],
  \   ['command:/foo', 1, 'textDocument/didClose', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \     },
  \   }],
  \ ],
  \ g:message_list

Execute(A message should be sent if the document was opened for tsserver):
  call ale#lsp#Register('command', '/foo', {})
  call ale#lsp#MarkConnectionAsTsserver('command:/foo')

  call ale#lsp#OpenDocument('command:/foo', bufnr(''), 'lang')
  call ale#engine#Cleanup(bufnr(''))
  " We should only send the message once.
  call ale#engine#Cleanup(bufnr(''))

  AssertEqual
  \ [
  \   ['command:/foo', 1, 'ts@open', {'file': expand('%:p')}],
  \   ['command:/foo', 1, 'ts@close', {'file': expand('%:p')}],
  \ ],
  \ g:message_list

Execute(Re-opening and closing the documents should work):
  call ale#lsp#Register('command', '/foo', {})
  call MarkAllConnectionsInitialized()

  call ale#lsp#OpenDocument('command:/foo', bufnr(''), 'lang')
  call ale#engine#Cleanup(bufnr(''))
  call ale#lsp#OpenDocument('command:/foo', bufnr(''), 'lang')
  call ale#engine#Cleanup(bufnr(''))

  AssertEqual
  \ [
  \   ['command:/foo', 1, 'textDocument/didOpen', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \       'version': g:ale_lsp_next_version_id - 2,
  \       'languageId': 'lang',
  \       'text': "\n",
  \     },
  \   }],
  \   ['command:/foo', 1, 'textDocument/didClose', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \     },
  \   }],
  \   ['command:/foo', 1, 'textDocument/didOpen', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \       'version': g:ale_lsp_next_version_id - 1,
  \       'languageId': 'lang',
  \       'text': "\n",
  \     },
  \   }],
  \   ['command:/foo', 1, 'textDocument/didClose', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \     },
  \   }],
  \ ],
  \ g:message_list

Execute(Messages for closing documents should be sent to each server):
  call ale#lsp#Register('command', '/foo', {})
  call ale#lsp#Register('command', '/bar', {})
  call MarkAllConnectionsInitialized()

  call ale#lsp#OpenDocument('command:/foo', bufnr(''), 'lang')
  call ale#lsp#OpenDocument('command:/bar', bufnr(''), 'lang')
  call ale#engine#Cleanup(bufnr(''))
  " We should only send the message once.
  call ale#engine#Cleanup(bufnr(''))

  AssertEqual
  \ [
  \   ['command:/foo', 1, 'textDocument/didOpen', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \       'version': g:ale_lsp_next_version_id - 2,
  \       'languageId': 'lang',
  \       'text': "\n",
  \     },
  \   }],
  \   ['command:/bar', 1, 'textDocument/didOpen', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \       'version': g:ale_lsp_next_version_id - 1,
  \       'languageId': 'lang',
  \       'text': "\n",
  \     },
  \   }],
  \   ['command:/bar', 1, 'textDocument/didClose', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \     },
  \   }],
  \   ['command:/foo', 1, 'textDocument/didClose', {
  \     'textDocument': {
  \       'uri': ale#path#ToFileURI(expand('%:p')),
  \     },
  \   }],
  \ ],
  \ g:message_list