Update minimum supported NeoVim version to 0.6.0

Stop officially supporting NeoVim versions below 0.6.0, without
necessarily breaking ALE for people using older versions.

8 files changed, 66 insertions, 71 deletions

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 4910a5ed..27d02c1a 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -28,7 +28,7 @@ jobs:
         vim-version:
           - '--vim-80-only'
           - '--vim-90-only'
-          - '--neovim-02-only'
+          - '--neovim-06-only'
           - '--neovim-08-only'
           - '--linters-only'
     steps:
diff --git a/Dockerfile b/Dockerfile
index c7cc6e98..e751763c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@ FROM testbed/vim:${TESTBED_VIM_VERSION}
 
 RUN install_vim -tag v8.0.0027 -build \
                 -tag v9.0.0297 -build \
-                -tag neovim:v0.2.0 -build \
+                -tag neovim:v0.6.0 -build \
                 -tag neovim:v0.8.0 -build
 
 ENV PACKAGES="\
diff --git a/README.md b/README.md
index 42d1d6b6..a61358b4 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 ![ALE Logo by Mark Grealish - https://www.bhalash.com/](https://user-images.githubusercontent.com/3518142/59195920-2c339500-8b85-11e9-9c22-f6b7f69637b8.jpg)
 
 ALE (Asynchronous Lint Engine) is a plugin providing linting (syntax checking
-and semantic errors) in NeoVim 0.2.0+ and Vim 8.0+ while you edit your text files,
+and semantic errors) in NeoVim 0.6.0+ and Vim 8.0+ while you edit your text files,
 and acts as a Vim [Language Server Protocol](https://langserver.org/) client.
 
 <video autoplay="true" muted="true" loop="true" controls="false" src="https://user-images.githubusercontent.com/3518142/210141215-8f2ff760-6a87-4704-a11e-c109b8e9ec41.mp4" title="An example showing what ALE can do."></video>
diff --git a/doc/ale-development.txt b/doc/ale-development.txt
index 6bc009fd..6ba03da1 100644
--- a/doc/ale-development.txt
+++ b/doc/ale-development.txt
@@ -48,7 +48,7 @@ documented functions and options, until a major version is planned. Breaking
 changes should be preceded by a deprecation phase complete with warnings.
 Changes required for security may be an exception.
 
-ALE supports Vim 8 and above, and NeoVim 0.2.0 or newer. These are the
+ALE supports Vim 8 and above, and NeoVim 0.6.0 or newer. These are the
 earliest versions of Vim and NeoVim which support |job|, |timer|, |closure|,
 and |lambda| features. All ALE code should be written so it is compatible with
 these versions of Vim, or with version checks so particular features can
@@ -156,7 +156,7 @@ environments.
 
 1. Vim 8.0.0027 on Linux via GitHub Actions.
 2. Vim 9.0.0297 on Linux via GitHub Actions.
-3. NeoVim 0.2.0 on Linux via GitHub Actions.
+3. NeoVim 0.6.0 on Linux via GitHub Actions.
 4. NeoVim 0.8.0 on Linux via GitHub Actions.
 6. Vim 8 (stable builds) on Windows via AppVeyor.
 
diff --git a/plugin/ale.vim b/plugin/ale.vim
index e239f233..7eccdb5f 100644
--- a/plugin/ale.vim
+++ b/plugin/ale.vim
@@ -14,6 +14,7 @@ let g:loaded_ale_dont_use_this_in_other_plugins_please = 1
 
 " A flag for detecting if the required features are set.
 if has('nvim')
+    " We check for NeoVim 0.2.0+, but we only officially support NeoVim 0.6.0
     let s:has_features = has('timers') && has('nvim-0.2.0')
 else
     " Check if Job and Channel functions are available, instead of the
@@ -25,7 +26,7 @@ if !s:has_features
     " Only output a warning if editing some special files.
     if index(['', 'gitcommit'], &filetype) == -1
         " no-custom-checks
-        echoerr 'ALE requires NeoVim >= 0.2.0 or Vim 8 with +timers +job +channel'
+        echoerr 'ALE requires NeoVim >= 0.6.0 or Vim 8 with +timers +job +channel'
         " no-custom-checks
         echoerr 'Please update your editor appropriately.'
     endif
diff --git a/run-tests b/run-tests
index a2b83bd2..a952663f 100755
--- a/run-tests
+++ b/run-tests
@@ -24,7 +24,7 @@ tests='test/*.vader test/*/*.vader test/*/*/*.vader'
 # These flags are forwarded to the script for running Vader tests.
 verbose_flag=''
 quiet_flag=''
-run_neovim_02_tests=1
+run_neovim_06_tests=1
 run_neovim_08_tests=1
 run_vim_80_tests=1
 run_vim_90_tests=1
@@ -43,7 +43,7 @@ while [ $# -ne 0 ]; do
     --build-image)
         run_vim_80_tests=0
         run_vim_90_tests=0
-        run_neovim_02_tests=0
+        run_neovim_06_tests=0
         run_neovim_08_tests=0
         run_linters=0
         shift
@@ -54,7 +54,7 @@ while [ $# -ne 0 ]; do
         run_linters=0
         shift
     ;;
-    --neovim-02-only)
+    --neovim-06-only)
         run_neovim_08_tests=0
         run_vim_80_tests=0
         run_vim_90_tests=0
@@ -62,27 +62,27 @@ while [ $# -ne 0 ]; do
         shift
     ;;
     --neovim-08-only)
-        run_neovim_02_tests=0
+        run_neovim_06_tests=0
         run_vim_80_tests=0
         run_vim_90_tests=0
         run_linters=0
         shift
     ;;
     --vim-only)
-        run_neovim_02_tests=0
+        run_neovim_06_tests=0
         run_neovim_08_tests=0
         run_linters=0
         shift
     ;;
     --vim-80-only)
-        run_neovim_02_tests=0
+        run_neovim_06_tests=0
         run_neovim_08_tests=0
         run_vim_90_tests=0
         run_linters=0
         shift
     ;;
     --vim-90-only)
-        run_neovim_02_tests=0
+        run_neovim_06_tests=0
         run_neovim_08_tests=0
         run_vim_80_tests=0
         run_linters=0
@@ -91,14 +91,14 @@ while [ $# -ne 0 ]; do
     --linters-only)
         run_vim_80_tests=0
         run_vim_90_tests=0
-        run_neovim_02_tests=0
+        run_neovim_06_tests=0
         run_neovim_08_tests=0
         shift
     ;;
     --fast)
         run_vim_80_tests=0
         run_vim_90_tests=0
-        run_neovim_02_tests=0
+        run_neovim_06_tests=0
         run_neovim_08_tests=1
         shift
     ;;
@@ -113,7 +113,7 @@ while [ $# -ne 0 ]; do
         echo '  -q                Hide output for successful tests'
         echo '  --build-image     Run docker image build only.'
         echo '  --neovim-only     Run tests only for NeoVim'
-        echo '  --neovim-02-only  Run tests only for NeoVim 0.2'
+        echo '  --neovim-06-only  Run tests only for NeoVim 0.2'
         echo '  --neovim-08-only  Run tests only for NeoVim 0.8'
         echo '  --vim-only        Run tests only for Vim'
         echo '  --vim-80-only     Run tests only for Vim 8.2'
@@ -228,7 +228,7 @@ trap cancel_tests INT TERM
 for vim in $(docker run --rm "$DOCKER_RUN_IMAGE" ls /vim-build/bin | grep '^neovim\|^vim' ); do
     if ( [[ $vim =~ ^vim-v8.0 ]] && ((run_vim_80_tests)) ) \
     || ( [[ $vim =~ ^vim-v9.0 ]] && ((run_vim_90_tests)) ) \
-    || ( [[ $vim =~ ^neovim-v0.2 ]] && ((run_neovim_02_tests)) ) \
+    || ( [[ $vim =~ ^neovim-v0.6 ]] && ((run_neovim_06_tests)) ) \
     || ( [[ $vim =~ ^neovim-v0.8 ]] && ((run_neovim_08_tests)) ); then
         echo "Starting Vim: $vim..."
         file_number=$((file_number+1))
diff --git a/test/completion/test_omnifunc_completion.vader b/test/completion/test_omnifunc_completion.vader
index 1db64705..c9ecd205 100644
--- a/test/completion/test_omnifunc_completion.vader
+++ b/test/completion/test_omnifunc_completion.vader
@@ -45,7 +45,7 @@ Execute(The start position should be returned when results can be requested):
   AssertEqual 11, ale#completion#OmniFunc(1, '')
 
 Execute(The omnifunc function should return async results):
-  " Neovim 0.2.0 and 0.4.4 struggles at running these tests.
+  " Neovim struggles at running these tests.
   if !has('nvim')
     call timer_start(0, function('SetCompletionResult'))
 
diff --git a/test/test_neovim_diagnostics.vader b/test/test_neovim_diagnostics.vader
index 41997097..4cef8d35 100644
--- a/test/test_neovim_diagnostics.vader
+++ b/test/test_neovim_diagnostics.vader
@@ -2,10 +2,6 @@ Before:
   Save g:ale_use_neovim_diagnostics_api
 
   function! CollectMessages(buffer)
-    if !has('nvim-0.6')
-        return
-    endif
-
     let l:messages = []
     for l:diag in v:lua.vim.diagnostic.get(a:buffer)
         call add(l:messages, l:diag.message)
@@ -22,56 +18,54 @@ After:
 
 Execute(Should only set diagnostics belonging to the given buffer):
   if has('nvim-0.6')
+    let b:other_bufnr = bufnr('/foo/bar/baz', 1)
+    " Make sure we actually get another buffer number, or the test is invalid.
+    AssertNotEqual -1, b:other_bufnr
 
-  let b:other_bufnr = bufnr('/foo/bar/baz', 1)
-  " Make sure we actually get another buffer number, or the test is invalid.
-  AssertNotEqual -1, b:other_bufnr
-
-  let g:ale_use_neovim_diagnostics_api = 1
-
-  call ale#engine#SetResults(bufnr('%'), [
-  \  {
-  \    'lnum': 1,
-  \    'col': 10,
-  \    'bufnr': bufnr('%'),
-  \    'vcol': 0,
-  \    'linter_name': 'bettercode',
-  \    'nr': -1,
-  \    'type': 'W',
-  \    'text': 'A',
-  \  },
-  \  {
-  \    'lnum': 2,
-  \    'col': 10,
-  \    'bufnr': b:other_bufnr,
-  \    'vcol': 0,
-  \    'linter_name': 'bettercode',
-  \    'nr': -1,
-  \    'type': 'W',
-  \    'text': 'B',
-  \  },
-  \  {
-  \    'lnum': 3,
-  \    'col': 1,
-  \    'bufnr': bufnr('%'),
-  \    'vcol': 0,
-  \    'linter_name': 'bettercode',
-  \    'nr': -1,
-  \    'type': 'E',
-  \    'text': 'C',
-  \  },
-  \  {
-  \    'lnum': 4,
-  \    'col': 1,
-  \    'bufnr': b:other_bufnr,
-  \    'vcol': 0,
-  \    'linter_name': 'bettercode',
-  \    'nr': -1,
-  \    'type': 'E',
-  \    'text': 'D',
-  \  },
-  \])
+    let g:ale_use_neovim_diagnostics_api = 1
 
-  AssertEqual ["A", "C"], CollectMessages(bufnr('%'))
+    call ale#engine#SetResults(bufnr('%'), [
+    \  {
+    \    'lnum': 1,
+    \    'col': 10,
+    \    'bufnr': bufnr('%'),
+    \    'vcol': 0,
+    \    'linter_name': 'bettercode',
+    \    'nr': -1,
+    \    'type': 'W',
+    \    'text': 'A',
+    \  },
+    \  {
+    \    'lnum': 2,
+    \    'col': 10,
+    \    'bufnr': b:other_bufnr,
+    \    'vcol': 0,
+    \    'linter_name': 'bettercode',
+    \    'nr': -1,
+    \    'type': 'W',
+    \    'text': 'B',
+    \  },
+    \  {
+    \    'lnum': 3,
+    \    'col': 1,
+    \    'bufnr': bufnr('%'),
+    \    'vcol': 0,
+    \    'linter_name': 'bettercode',
+    \    'nr': -1,
+    \    'type': 'E',
+    \    'text': 'C',
+    \  },
+    \  {
+    \    'lnum': 4,
+    \    'col': 1,
+    \    'bufnr': b:other_bufnr,
+    \    'vcol': 0,
+    \    'linter_name': 'bettercode',
+    \    'nr': -1,
+    \    'type': 'E',
+    \    'text': 'D',
+    \  },
+    \])
 
+    AssertEqual ["A", "C"], CollectMessages(bufnr('%'))
   endif