Close #2556 - Support filename mapping

ALE now supports mapping files between different systems for running
linters and fixers with Docker, in virtual machines, in servers, etc.

1 files changed, 181 insertions, 16 deletions

diff --git a/doc/ale.txt b/doc/ale.txt
index 81271105..7327959b 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -9,8 +9,9 @@ CONTENTS                                                         *ale-contents*
   1. Introduction.........................|ale-introduction|
   2. Supported Languages & Tools..........|ale-support|
   3. Linting..............................|ale-lint|
-    3.1 Adding Language Servers...........|ale-lint-language-servers|
-    3.2 Other Sources.....................|ale-lint-other-sources|
+    3.1 Linting On Other Machines.........|ale-lint-other-machines|
+    3.2 Adding Language Servers...........|ale-lint-language-servers|
+    3.3 Other Sources.....................|ale-lint-other-sources|
   4. Fixing Problems......................|ale-fix|
   5. Language Server Protocol Support.....|ale-lsp|
     5.1 Completion........................|ale-completion|
@@ -148,7 +149,61 @@ ALE offers several options for controlling which linters are run.
 
 
 -------------------------------------------------------------------------------
-3.1 Adding Language Servers                         *ale-lint-language-servers*
+3.1 Linting On Other Machines                         *ale-lint-other-machines*
+
+ALE offers support for running linters or fixers on files you are editing
+locally on other machines, so long as the other machine has access the file
+you are editing. This could be a linter or fixer run inside of a Docker image,
+running in a virtual machine, running on a remote server, etc.
+
+In order to run tools on other machines, you will need to configure your tools
+to run via scripts that execute commands on those machines, such as by setting
+the ALE `_executable` options for those tools to a path for a script to run,
+or by using |g:ale_command_wrapper| to specify a script to wrap all commands
+that are run by ALE, before they are executed. For tools that ALE runs where
+ALE looks for locally installed executables first, you may need to set the
+`_use_global` options for those tools to `1`, or you can set
+|g:ale_use_global_executables| to `1` before ALE is loaded to only use global
+executables for all tools.
+
+In order for ALE to properly lint or fix files which are running on another
+file system, you must provide ALE with |List|s of strings for mapping paths to
+and from your local file system and the remote file system, such as the file
+system of your Docker container. See |g:ale_filename_mappings| for all of the
+different ways these filename mappings can be configured.
+
+For example, you might configure `pylint` to run via Docker by creating a
+script like so. >
+
+  #!/usr/bin/env bash
+
+  exec docker run --rm -v "$(pwd):/data" cytopia/pylint "$@"
+<
+With the above script in mind, you might configure ALE to lint your Python
+project with `pylint` by providing the path to the script to execute, and
+mappings which describe how to between the two file systems in your
+`python.vim` |ftplugin| file, like so: >
+
+  if expand('%:p') =~# '^/home/w0rp/git/test-pylint/'
+    let b:ale_linters = ['pylint']
+    let b:ale_python_pylint_use_global = 1
+    " This is the path to the script above.
+    let b:ale_python_pylint_executable = '/home/w0rp/git/test-pylint/pylint.sh'
+    " /data matches the path in Docker.
+    let b:ale_filename_mappings = {
+    \ 'pylint': [
+    \   ['/home/w0rp/git/test-pylint', '/data'],
+    \ ],
+    \}
+  endif
+<
+
+You might consider using a Vim plugin for loading Vim configuration files
+specific to each project, if you have a lot of projects to manage.
+
+
+-------------------------------------------------------------------------------
+3.2 Adding Language Servers                         *ale-lint-language-servers*
 
 ALE comes with many default configurations for language servers, so they can
 be detected and run automatically. ALE can connect to other language servers
@@ -189,7 +244,7 @@ address to connect to instead. >
 
 
 -------------------------------------------------------------------------------
-3.2 Other Sources                                      *ale-lint-other-sources*
+3.3 Other Sources                                      *ale-lint-other-sources*
 
 Problems for a buffer can be taken from other sources and rendered by ALE.
 This allows ALE to be used in combination with other plugins which also want
@@ -356,6 +411,10 @@ by default.
 Fixers can be disabled on save with |g:ale_fix_on_save_ignore|. They will
 still be run when you manually run |ALEFix|.
 
+Fixers can be run on another machines, just like linters, such as fixers run
+from a Docker container, running in a virtual machine, running a remote
+server, etc. See |ale-lint-other-machines|.
+
 
 ===============================================================================
 5. Language Server Protocol Support                                   *ale-lsp*
@@ -1286,6 +1345,90 @@ g:ale_linter_aliases                                     *g:ale_linter_aliases*
 <
   No linters will be loaded when the buffer's filetype is empty.
 
+
+g:ale_filename_mappings                               *g:ale_filename_mappings*
+                                                      *b:ale_filename_mappings*
+
+  Type: |Dictionary| or |List|
+  Default: `{}`
+
+  Either a |Dictionary| mapping a linter or fixer name, as displayed in
+  |:ALEInfo|, to a |List| of two-item |List|s for filename mappings, or just a
+  |List| of two-item |List|s. When given some paths to files, the value of
+  this setting will be used to convert filenames on a local file system to
+  filenames on some remote file system, such as paths in a Docker image,
+  virtual machine, or network drive.
+
+  For example: >
+
+  let g:ale_filename_mappings = {
+  \   'pylint': [
+  \       ['/home/john/proj', '/data'],
+  \   ],
+  \}
+<
+  With the above configuration, a filename such as `/home/john/proj/foo.py`
+  will be provided to the linter/fixer as `/data/foo.py`, and paths parsed
+  from linter results such as `/data/foo.py` will be converted back to
+  `/home/john/proj/foo.py`.
+
+  You can use `*` as to apply a |List| of filename mappings to all other
+  linters or fixers not otherwise matched. >
+
+  " Use one List of paths for pylint.
+  " Use another List of paths for everything else.
+  let g:ale_filename_mappings = {
+  \   'pylint': [
+  \       ['/home/john/proj', '/data'],
+  \   ],
+  \   '*': [
+  \       ['/home/john/proj', '/other-data'],
+  \   ],
+  \}
+<
+  If you just want every single linter or fixer to use the same filename
+  mapping, you can just use a |List|. >
+
+  " Same as above, but for ALL linters and fixers.
+  let g:ale_filename_mappings = [
+  \   ['/home/john/proj', '/data'],
+  \]
+<
+  You can provide many such filename paths for multiple projects. Paths are
+  matched by checking if the start of a file path matches the given strings,
+  in a case-sensitive manner. Earlier entries in the |List| will be tried
+  before later entries when mapping to a given file system.
+
+  Buffer-local options can be set to the same values to override the global
+  options, such as in |ftplugin| files.
+
+  NOTE: Only fixers registered with a short name can support filename mapping
+  by their fixer names. See |ale-fix|. Filename mappings set for all tools by
+  using only a |List| for the setting will also be applied to fixers not in
+  the registry.
+
+  NOTE: In order for this filename mapping to work correctly, linters and
+  fixers must exclusively determine paths to files to lint or fix via ALE
+  command formatting as per |ale-command-format-strings|, and paths parsed
+  from linter files must be provided in `filename` keys if a linter returns
+  results for more than one file at a time, as per |ale-loclist-format|. If
+  you discover a linter or fixer which does not behave properly, please report
+  it as an issue.
+
+  If you are running a linter or fixer through Docker or another remote file
+  system, you may have to mount your temporary directory, which you can
+  discover with the following command: >
+
+  :echo fnamemodify(tempname(), ':h:h')
+<
+  You should provide a mapping from this temporary directory to whatever you
+  mount this directory to in Docker, or whatever remote file system you are
+  working with.
+
+  You can inspect the filename mappings ALE will use with the
+  |ale#GetFilenameMappings()| function.
+
+
 g:ale_linters                                                   *g:ale_linters*
                                                                 *b:ale_linters*
   Type: |Dictionary|
@@ -3073,6 +3216,15 @@ ale#Env(variable_name, value)                                       *ale#Env()*
     'set VAR="some value" && command' # On Windows
 
 
+ale#GetFilenameMappings(buffer, name)               *ale#GetFilenameMappings()*
+
+  Given a `buffer` and the `name` of either a linter for fixer, return a
+  |List| of two-item |List|s that describe mapping to and from the local and
+  foreign file systems for running a particular linter or fixer.
+
+  See |g:ale_filename_mappings| for details on filename mapping.
+
+
 ale#Has(feature)                                                    *ale#Has()*
 
   Return `1` if ALE supports a given feature, like |has()| for Vim features.
@@ -3187,23 +3339,36 @@ ale#command#Run(buffer, command, callback, [options])       *ale#command#Run()*
 <
   The following `options` can be provided.
 
-    `output_stream` - Either `'stdout'`, `'stderr'`, `'both'`, or `'none`' for
-                    selecting which output streams to read lines from.
+    `output_stream`     - Either `'stdout'`, `'stderr'`, `'both'`, or
+                        `'none`' for selecting which output streams to read
+                        lines from.
+
+                        The default is `'stdout'`
+
+    `executable`        - An executable for formatting into `%e` in the
+                        command. If this option is not provided, formatting
+                        commands with `%e` will not work.
+
+    `read_buffer`       - If set to `1`, the buffer will be piped into the
+                        command.
+
+                        The default is `0`.
 
-                    The default is `'stdout'`
+    `input`             - When creating temporary files with `%t` or piping
+                        text into a command `input` can be set to a |List| of
+                        text to use instead of the buffer's text.
 
-    `executable`    - An executable for formatting into `%e` in the command.
-                    If this option is not provided, formatting commands with
-                    `%e` will not work.
+    `filename_mappings` - A |List| of two-item |List|s describing filename
+                        mappings to apply for formatted filenames in the
+                        command string, as per |g:ale_filename_mappings|.
 
-    `read_buffer`   - If set to `1`, the buffer will be piped into the
-                    command.
+                        If the call to this function is being used for a
+                        linter or fixer, the mappings should be provided with
+                        this option, and can be retrieved easily with
+                        |ale#GetFilenameMappings()|.
 
-                    The default is `0`.
+                        The default is `[]`.
 
-    `input`         - When creating temporary files with `%t` or piping text
-                    into a command `input` can be set to a |List| of text to
-                    use instead of the buffer's text.
 
 
 ale#command#EscapeCommandPart(command_part)   *ale#command#EscapeCommandPart()*