Add buf linter and fixer (#4128)

* Add buf lint to linters

* Add buf format to fixers

* Fix test/linter/test_buf_lint.vader

* Fix test/fixers/test_buf_format_fixer_callback.vader

* Simplify test/test-files/proto/testfile.proto

* Add buf-lint alias and rename linter

10 files changed, 129 insertions, 2 deletions

diff --git a/ale_linters/proto/buf_lint.vim b/ale_linters/proto/buf_lint.vim
new file mode 100644
index 00000000..e68494a7
--- /dev/null
+++ b/ale_linters/proto/buf_lint.vim
@@ -0,0 +1,23 @@
+" Author: Alex McKinney <alexmckinney01@gmail.com>
+" Description: Run buf lint.
+
+call ale#Set('proto_buf_lint_executable', 'buf')
+call ale#Set('proto_buf_lint_config', '')
+
+function! ale_linters#proto#buf_lint#GetCommand(buffer) abort
+    let l:config = ale#Var(a:buffer, 'proto_buf_lint_config')
+
+    return '%e lint'
+    \ . (!empty(l:config) ? ' --config=' . ale#Escape(l:config) : '')
+    \ . ' %s#include_package_files=true'
+endfunction
+
+call ale#linter#Define('proto', {
+\   'name': 'buf_lint',
+\   'aliases': ['buf-lint'],
+\   'lint_file': 1,
+\   'output_stream': 'stdout',
+\   'executable': {b -> ale#Var(b, 'proto_buf_lint_executable')},
+\   'command': function('ale_linters#proto#buf_lint#GetCommand'),
+\   'callback': 'ale#handlers#unix#HandleAsError',
+\})
diff --git a/autoload/ale/fix/registry.vim b/autoload/ale/fix/registry.vim
index f9b94843..6ac617d8 100644
--- a/autoload/ale/fix/registry.vim
+++ b/autoload/ale/fix/registry.vim
@@ -37,6 +37,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['python'],
 \       'description': 'Fix PEP8 issues with black.',
 \   },
+\   'buf-format': {
+\       'function': 'ale#fixers#buf_format#Fix',
+\       'suggested_filetypes': ['proto'],
+\       'description': 'Fix .proto files with buf format.',
+\   },
 \   'buildifier': {
 \       'function': 'ale#fixers#buildifier#Fix',
 \       'suggested_filetypes': ['bzl'],
diff --git a/autoload/ale/fixers/buf_format.vim b/autoload/ale/fixers/buf_format.vim
new file mode 100644
index 00000000..c2c156b7
--- /dev/null
+++ b/autoload/ale/fixers/buf_format.vim
@@ -0,0 +1,12 @@
+" Author: Alex McKinney <alexmckinney01@gmail.com>
+" Description: Run buf format.
+
+call ale#Set('proto_buf_format_executable', 'buf')
+
+function! ale#fixers#buf_format#Fix(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'proto_buf_format_executable')
+
+    return {
+    \   'command': ale#Escape(l:executable) . ' format %t',
+    \}
+endfunction
diff --git a/doc/ale-proto.txt b/doc/ale-proto.txt
index 8ab56a14..a1bf1303 100644
--- a/doc/ale-proto.txt
+++ b/doc/ale-proto.txt
@@ -8,14 +8,52 @@ Integration Information
 To enable `.proto` file linting, update |g:ale_linters| as appropriate:
 >
   " Enable linter for .proto files
-  let g:ale_linters = {'proto': ['protoc-gen-lint', 'protolint']}
+  let g:ale_linters = {'proto': ['buf-lint', 'protoc-gen-lint', 'protolint']}
 
 To enable `.proto` file fixing, update |g:ale_fixers| as appropriate:
 >
   " Enable linter for .proto files
-  let b:ale_fixers = {'proto': ['protolint']}
+  let b:ale_fixers = {'proto': ['buf-format', 'protolint']}
 <
 ===============================================================================
+buf-format                                                *ale-proto-buf-format*
+
+  The formatter uses `buf`, a fully-featured Protobuf compiler that doesn't depend
+  on `protoc`. Make sure the `buf` binary is available in the system path, or
+  set ale_proto_buf_format_executable.
+
+g:ale_proto_buf_format_executable           *g:ale_proto_buf_format_executable*
+
+  Type: |String|
+  Default: 'buf'
+
+  This variable can be changed to modify the executable used for buf.
+
+===============================================================================
+buf-lint                                                    *ale-proto-buf-lint*
+
+  The linter uses `buf`, a fully-featured Protobuf compiler that doesn't depend
+  on `protoc`. Make sure the `buf` binary is available in the system path, or
+  set ale_proto_buf_lint_executable.
+
+g:ale_proto_buf_lint_executable               *g:ale_proto_buf_lint_executable*
+
+  Type: |String|
+  Default: 'buf'
+
+  This variable can be changed to modify the executable used for buf.
+
+g:ale_proto_buf_lint_config                       *g:ale_proto_buf_lint_config*
+
+  Type: |String|
+  Default: `''`
+
+  A path to a buf configuration file.
+
+  The path to the configuration file can be an absolute path or a relative
+  path. ALE will search for the relative path in parent directories.
+
+===============================================================================
 protoc-gen-lint                                      *ale-proto-protoc-gen-lint*
 
   The linter is a plugin for the `protoc` binary. As long as the binary resides
diff --git a/doc/ale-supported-languages-and-tools.txt b/doc/ale-supported-languages-and-tools.txt
index 67efc6ec..f0ff29a7 100644
--- a/doc/ale-supported-languages-and-tools.txt
+++ b/doc/ale-supported-languages-and-tools.txt
@@ -430,6 +430,8 @@ Notes:
 * Prolog
   * `swipl`
 * proto
+  * `buf-format`!!
+  * `buf-lint`!!
   * `protoc-gen-lint`!!
   * `protolint`!!
 * Pug
diff --git a/doc/ale.txt b/doc/ale.txt
index 0250637c..96ecd5b8 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -3060,6 +3060,8 @@ documented in additional help files.
   prolog..................................|ale-prolog-options|
     swipl.................................|ale-prolog-swipl|
   proto...................................|ale-proto-options|
+    buf-format............................|ale-proto-buf-format|
+    buf-lint..............................|ale-proto-buf-lint|
     protoc-gen-lint.......................|ale-proto-protoc-gen-lint|
     protolint.............................|ale-proto-protolint|
   pug.....................................|ale-pug-options|
diff --git a/supported-tools.md b/supported-tools.md
index 491e7b96..3e9bc2f8 100644
--- a/supported-tools.md
+++ b/supported-tools.md
@@ -439,6 +439,8 @@ formatting.
 * Prolog
   * [swipl](https://github.com/SWI-Prolog/swipl-devel)
 * proto
+  * [buf-format](https://github.com/bufbuild/buf) :floppy_disk:
+  * [buf-lint](https://github.com/bufbuild/buf) :floppy_disk:
   * [protoc-gen-lint](https://github.com/ckaznocha/protoc-gen-lint) :floppy_disk:
   * [protolint](https://github.com/yoheimuta/protolint) :floppy_disk:
 * Pug
diff --git a/test/fixers/test_buf_format_fixer_callback.vader b/test/fixers/test_buf_format_fixer_callback.vader
new file mode 100644
index 00000000..ee484820
--- /dev/null
+++ b/test/fixers/test_buf_format_fixer_callback.vader
@@ -0,0 +1,21 @@
+Before:
+  Save g:ale_proto_buf_format_executable
+
+  " Use an invalid global executable, so we don't match it.
+  let g:ale_proto_buf_format_executable = 'xxxinvalid'
+
+  call ale#test#SetDirectory('/testplugin/test/fixers')
+
+After:
+  Restore
+
+  call ale#test#RestoreDirectory()
+
+Execute(The buf-format callback should return the correct default values):
+  call ale#test#SetFilename('../test-files/proto/testfile.proto')
+
+  AssertEqual
+  \ {
+  \   'command': ale#Escape('xxxinvalid') . ' format %t',
+  \ },
+  \ ale#fixers#buf_format#Fix(bufnr(''))
diff --git a/test/linter/test_buf_lint.vader b/test/linter/test_buf_lint.vader
new file mode 100644
index 00000000..7b8bb52c
--- /dev/null
+++ b/test/linter/test_buf_lint.vader
@@ -0,0 +1,22 @@
+Before:
+  call ale#assert#SetUpLinterTest('proto', 'buf_lint')
+  call ale#test#SetFilename('test.proto')
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(The default command should be correct):
+  AssertLinter 'buf',
+  \ ale#Escape('buf')
+  \ . ' lint'
+  \ . ' %s#include_package_files=true'
+
+Execute(The callback should include any additional options):
+  let b:ale_proto_buf_lint_executable = '/tmp/buf'
+  let b:ale_proto_buf_lint_config = '/tmp/buf.yaml'
+
+  AssertLinter '/tmp/buf',
+  \ ale#Escape('/tmp/buf')
+  \ . ' lint'
+  \ . ' --config=' . ale#Escape('/tmp/buf.yaml')
+  \ . ' %s#include_package_files=true'
diff --git a/test/test-files/proto/testfile.proto b/test/test-files/proto/testfile.proto
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/test/test-files/proto/testfile.proto