Some (all?) sources show errors on registration

Warning: I will close the issue without the minimal init.vim and the reproduction instructions.

Problems summary

Some sources cannot been registered.

…I cannot find this problem out caused by ddc.vim or sources. I detected this in ddc-around, neco-vim, ddc-buffer and so on.

Expected

All sources works good.

Environment Information

• ddc version (SHA1): 9073abe

• OS: macOS 11.5.2

• neovim/Vim :version output:

:version

:version
NVIM v0.6.0-dev+189-g274a3504a
Build type: Release
LuaJIT 2.1.0-beta3
Compiled by jinnouchi.yasushi@O-10413-MAC

Features: +acl +iconv +tui
See ":help feature-compile"

      システム vimrc: "$VIM/sysinit.vim"
       省略時の $VIM: "/usr/local/Cellar/neovim/HEAD-274a350/share/nvim"

Run :checkhealth for more info
続けるにはENTERを押すかコマンドを入力してください

• :checkhealth or :CheckHealth result(neovim only):

:checkhealth

health#lspconfig#check
========================================================================
## Checking language server protocol configuration
  - INFO: bashls: configuration checked.
  - INFO: denols: configuration checked.
  - INFO: vuels: configuration checked.
  - INFO: yamlls: configuration checked.
  - INFO: vimls: configuration checked.
  - INFO: terraformls: configuration checked.
  - INFO: sourcekit: configuration checked.
  - INFO: solargraph: configuration checked.
  - INFO: pyright: configuration checked.
  - INFO: intelephense: configuration checked.
  - INFO: dockerls: configuration checked.
  - ERROR: cssls: The given command "vscode-css-language-server" is not executable.
  - INFO: clangd: configuration checked.
  - INFO: tsserver: configuration checked.
  - INFO: efm: configuration checked.
  - ERROR: html: The given command "vscode-html-language-server" is not executable.
  - INFO: gopls: configuration checked.
  - INFO: sumneko_lua: configuration checked.
  - INFO: teal: configuration checked.

health#nvim#check
========================================================================
## Configuration
  - OK: no issues found

## Performance
  - OK: Build type: Release

## Remote Plugins
  - OK: Up to date

## terminal
  - INFO: key_backspace (kbs) terminfo entry: key_backspace=^H
  - INFO: key_dc (kdch1) terminfo entry: key_dc=\E[3~
  - INFO: $TERM_PROGRAM='tmux'
  - INFO: $COLORTERM='truecolor'

## tmux
  - OK: escape-time: 0
  - INFO: Checking stuff
  - OK: focus-events: on
  - INFO: $TERM: xterm-256color
  - ERROR: $TERM should be "screen-256color" or "tmux-256color" in tmux. Colors might look wrong.
    - ADVICE:
      - Set default-terminal in ~/.tmux.conf:
          set-option -g default-terminal "screen-256color"
      - https://github.com/neovim/neovim/wiki/FAQ
  - WARNING: Neither Tc nor RGB capability set. True colors are disabled. |'termguicolors'| won't work properly.
    - ADVICE:
      - Put this in your ~/.tmux.conf and replace XXX by your $TERM outside of tmux:
          set-option -sa terminal-overrides ',XXX:RGB'
      - For older tmux versions use this instead:
          set-option -ga terminal-overrides ',XXX:Tc'

health#provider#check
========================================================================
## Clipboard (optional)
  - OK: Clipboard tool found: pbcopy

## Python 2 provider (optional)
  - WARNING: No Python executable found that can `import neovim`. Using the first available executable for diagnostics.
  - ERROR: Python provider error:
    - ADVICE:
      - provider/pythonx: Could not load Python 2:
          /usr/bin/python2 does not have the "neovim" module. :help |provider-python|
          /usr/bin/python2.7 does not have the "neovim" module. :help |provider-python|
          python2.6 not found in search path or not executable.
          /usr/bin/python does not have the "neovim" module. :help |provider-python|
  - INFO: Executable: Not found

## Python 3 provider (optional)
  - INFO: `g:python3_host_prog` is not set.  Searching for python3 in the environment.
  - INFO: Multiple python3 executables found.  Set `g:python3_host_prog` to avoid surprises.
  - INFO: Executable: /usr/local/bin/python3
  - INFO: Other python executable: /usr/bin/python3
  - INFO: Python version: 3.9.6
  - INFO: pynvim version: 0.4.2 (outdated; from ~/Library/Python/3.9/lib/python/site-packages/neovim)
  - WARNING: Latest pynvim is NOT installed: 0.4.3

## Python virtualenv
  - OK: no $VIRTUAL_ENV

## Ruby provider (optional)
  - INFO: Ruby: ruby 3.0.2p107 (2021-07-07 revision 0db68f0233) [x86_64-darwin20]
  - WARNING: `neovim-ruby-host` not found.
    - ADVICE:
      - Run `gem install neovim` to ensure the neovim RubyGem is installed.
      - Run `gem environment` to ensure the gem bin directory is in $PATH.
      - If you are using rvm/rbenv/chruby, try "rehashing".
      - See :help |g:ruby_host_prog| for non-standard gem installations.

## Node.js provider (optional)
  - INFO: Node.js: v14.15.0
  - INFO: Nvim node.js host: /Users/jinnouchi.yasushi/.nodenv/versions/14.15.0/lib/node_modules/neovim/bin/cli.js
  - WARNING: Package "neovim" is out-of-date. Installed: 4.9.0, latest: 4.10.0
    - ADVICE:
      - Run in shell: npm install -g neovim
      - Run in shell (if you use yarn): yarn global add neovim

## Perl provider (optional)
  - ERROR: perl provider error:
    - ADVICE:
      - "Neovim::Ext" cpan module is not installed

health#treesitter#check
========================================================================
## Checking treesitter configuration
  - INFO: Runtime ABI version : 13

Provide a minimal init.vim/vimrc with less than 50 lines (Required!)

call ddc#custom#patch_global({
      \ 'keywordPattern': '[a-zA-Z_]\w*',
      \ 'smartCase': v:true,
      \ 'sources': ['around'],
      \ 'sourceOptions': {
      \   '_': {'matchers': ['matcher_head']},
      \   'around': {'mark': 'A'},
      \ },
      \ })
call ddc#enable()
let g:denops#debug = 1

See this Dockerfile

How to reproduce the problem from neovim/Vim startup (Required!)

1. Run this Dockerfile above
2. nvim .config/nvim/init.vim
3. Type some texts and wait for a while.
4. See this error

error

[denops] Error: Failed to call 'registerSource' with [{"name":"around","path":"/root/.local/share/nvim/site/pack/packer/start/ddc-around/denops/ddc/sources/around.ts"}]: TypeError: TS2416 [ERROR]: Property 'gatherCandidates' in type 'Source'
is not assignable to the same property in base type 'BaseSource'.
[denops]   Type '(args: { denops: Denops; sourceParams: Record<string, unknown>; completeStr: string; }) => Promise<Candidate[]>' is not assignable to type '{ (denops: Denops, context: Context, options: DdcOptions, sourceOptions: SourceOption
s, sourceParams: Record<string, unknown>, completeStr: string): Promise<...>; (args: GatherCandidatesArguments): Promise<...>; }'.
[denops]     Types of parameters 'args' and 'denops' are incompatible.
[denops]       Type 'Denops' is missing the following properties from type '{ denops: Denops; sourceParams: Record<string, unknown>; completeStr: string; }': denops, sourceParams, completeStr
[denops]   async gatherCandidates(args: {
[denops]         ~~~~~~~~~~~~~~~~
[denops]     at file:///root/.local/share/nvim/site/pack/packer/start/ddc-around/denops/ddc/sources/around.ts:21:9
[denops]     at async Ddc.registerSource (file:///root/.local/share/nvim/site/pack/packer/start/ddc.vim/denops/ddc/ddc.ts:129:17)
[denops]     at async Session.registerSource (file:///root/.local/share/nvim/site/pack/packer/start/ddc.vim/denops/ddc/app.ts:18:7)
[denops]     at async Session.dispatch (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:99:12)
[denops]     at async https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:108:18
[denops]     at async Session.handleRequest (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:104:29)
[denops]     at Session.call (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:207:13)
[denops]     at async Service.dispatch (file:///root/.local/share/nvim/site/pack/packer/start/denops.vim/denops/@denops-private/service/service.ts:112:14)
[denops]     at async Session.invoke (file:///root/.local/share/nvim/site/pack/packer/start/denops.vim/denops/@denops-private/service/host/nvim.ts:44:16)
[denops]     at async Session.dispatch (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:99:12)
[denops]     at async Session.handleNotification (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:130:7)
[denops] Error: Failed to call 'registerFilter' with [{"name":"matcher_head","path":"/root/.local/share/nvim/site/pack/packer/start/ddc-matcher_head/denops/ddc/filters/matcher_head.ts"}]: TypeError: TS2416 [ERROR]: Property 'filter' in type '
Filter' is not assignable to the same property in base type 'BaseFilter'.
[denops]   Type '(args: { sourceOptions: SourceOptions; completeStr: string; candidates: Candidate[]; }) => Promise<Candidate[]>' is not assignable to type '{ (denops: Denops, context: Context, options: DdcOptions, sourceOptions: SourceOption
s, filterOptions: FilterOptions, filterParams: Record<...>, completeStr: string, candidates: Candidate[]): Promise<...>; (args: FilterArguments): Promise<...>; }'.
[denops]     Types of parameters 'args' and 'denops' are incompatible.
[denops]       Type 'Denops' is missing the following properties from type '{ sourceOptions: SourceOptions; completeStr: string; candidates: Candidate[]; }': sourceOptions, completeStr, candidates
[denops]   filter(args: {
[denops]   ~~~~~~
[denops]     at file:///root/.local/share/nvim/site/pack/packer/start/ddc-matcher_head/denops/ddc/filters/matcher_head.ts:8:3
[denops]     at async Ddc.registerFilter (file:///root/.local/share/nvim/site/pack/packer/start/ddc.vim/denops/ddc/ddc.ts:139:17)
[denops]     at async Session.registerFilter (file:///root/.local/share/nvim/site/pack/packer/start/ddc.vim/denops/ddc/app.ts:22:7)
[denops]     at async Session.dispatch (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:99:12)
[denops]     at async https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:108:18
[denops]     at async Session.handleRequest (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:104:29)
[denops]     at Session.call (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:207:13)
[denops]     at async Service.dispatch (file:///root/.local/share/nvim/site/pack/packer/start/denops.vim/denops/@denops-private/service/service.ts:112:14)
[denops]     at async Session.invoke (file:///root/.local/share/nvim/site/pack/packer/start/denops.vim/denops/@denops-private/service/host/nvim.ts:44:16)
[denops]     at async Session.dispatch (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:99:12)
[denops]     at async Session.handleNotification (https://deno.land/x/msgpack_rpc@v3.1.0/session.ts:130:7)

Screenshot (if possible)

[Shougo]

I have fixed almost type errors. Please test the latest version.

Note: For external sources, fix type errors are needed.

[Shougo]

If the problem still exists, it is sources problem. Please report it in the sources issue instead.