IsCheckingBuffer(bufnr('')) remains 1 when a tsx file has no errors on successive lints

[danifus]

Information

VIM version

VIM - Vi IMproved 8.1 (2018 May 18, compiled Aug 22 2018 23:34:12)
macOS version

Operating System: macOS Mojave

What went wrong

Using tsserver, echo ale#engine#IsCheckingBuffer(bufnr('')) always returns 1 when the state goes from 'no errors' -> 'no errors'. The expected result is 0.

After going from 'errors' -> 'errors', 'errors' -> 'no errors' or 'no errors' -> 'errors', echo ale#engine#IsCheckingBuffer(bufnr('')) returns 0.

The result of IsCheckingBuffer remaining 1 is that the airline status line indicates that a linter is still running. I'm pretty sure that the linter completes quickly as the response for the other state changes returns very quickly in my testing.

Reproducing the bug

Minimal vimrc:

set nocompatible
filetype off
let &rtp = &rtp.','.<path_to_ale>
filetype plugin indent on
syntax enable
" Could omit ale_lint_on_text_changed but it makes it easier to check states:
let g:ale_lint_on_text_changed = 'never'
let g:ale_open_list = 1
let g:ale_linters_explicit = 1
let g:ale_linters = {'typescript': ['tsserver']}

autocmd BufNewFile,BufRead *.ts  set filetype=typescript
autocmd BufNewFile,BufRead *.tsx set filetype=typescript

The process:

1. Open a tsx file with no linting errors.
2. Create an error and save
3. Run echo ale#engine#IsCheckingBuffer(bufnr('')). The result I see here is 0
4. Remove the error and save
5. Run echo ale#engine#IsCheckingBuffer(bufnr('')). The result I see here is 0
6. Save the file again to initiate another lint
7. Run echo ale#engine#IsCheckingBuffer(bufnr('')). The result I see here is 1 and doesn't change.

:ALEInfo

 Current Filetype: typescript
Available Linters: ['eslint', 'tslint', 'tsserver', 'typecheck']
  Enabled Linters: ['tsserver']
 Suggested Fixers:
  'eslint' - Apply eslint --fix to a file.
  'prettier' - Apply prettier to a file.
  'remove_trailing_lines' - Remove all blank lines at the end of a file.
  'trim_whitespace' - Remove all trailing whitespace characters at the end of every line.
  'tslint' - Fix typescript files with tslint --fix.
 Linter Variables:
let g:ale_typescript_tsserver_config_path = ''
let g:ale_typescript_tsserver_executable = 'tsserver'
let g:ale_typescript_tsserver_use_global = 0
 Global Variables:
let g:ale_cache_executable_check_failures = v:null
let g:ale_change_sign_column_color = 0
let g:ale_command_wrapper = ''
let g:ale_completion_delay = v:null
let g:ale_completion_enabled = 0
let g:ale_completion_max_suggestions = v:null
let g:ale_echo_cursor = 1
let g:ale_echo_msg_error_str = 'Error'
let g:ale_echo_msg_format = '%code: %%s'
let g:ale_echo_msg_info_str = 'Info'
let g:ale_echo_msg_warning_str = 'Warning'
let g:ale_enabled = 1
let g:ale_fix_on_save = 0
let g:ale_fixers = {}
let g:ale_history_enabled = 1
let g:ale_history_log_output = 1
let g:ale_keep_list_window_open = 0
let g:ale_lint_delay = 200
let g:ale_lint_on_enter = 1
let g:ale_lint_on_filetype_changed = 1
let g:ale_lint_on_insert_leave = 0
let g:ale_lint_on_save = 1
let g:ale_lint_on_text_changed = 'never'
let g:ale_linter_aliases = {}
let g:ale_linters = {'typescript': ['tsserver']}
let g:ale_linters_explicit = 1
let g:ale_list_vertical = 0
let g:ale_list_window_size = 10
let g:ale_loclist_msg_format = '%code: %%s'
let g:ale_lsp_root = {}
let g:ale_max_buffer_history_size = 20
let g:ale_max_signs = -1
let g:ale_maximum_file_size = v:null
let g:ale_open_list = 1
let g:ale_pattern_options = v:null
let g:ale_pattern_options_enabled = v:null
let g:ale_set_balloons = 0
let g:ale_set_highlights = 1
let g:ale_set_loclist = 1
let g:ale_set_quickfix = 0
let g:ale_set_signs = 1
let g:ale_sign_column_always = 0
let g:ale_sign_error = '>>'
let g:ale_sign_info = '--'
let g:ale_sign_offset = 1000000
let g:ale_sign_style_error = '>>'
let g:ale_sign_style_warning = '--'
let g:ale_sign_warning = '--'
let g:ale_statusline_format = v:null
let g:ale_type_map = {}
let g:ale_use_global_executables = v:null
let g:ale_virtualtext_cursor = 0
let g:ale_warn_about_trailing_blank_lines = 1
let g:ale_warn_about_trailing_whitespace = 1
  Command History:
(executable check - success) '<path to>/node_modules/.bin/tsserver
(started) ['/usr/local/bin/bash', '-c', ''<path to>/node_modules/.bin/tsserver''']

Thanks for this project! It's great to use :)

[w0rp]

tsserver and LSP linters are now marked as inactive again after diagnostics have been received, and as busy when they are requested.

[danifus]

Brilliant! Thanks again for all your work on this project!