构建插件

{plugins, [
  {plugin_name, {git, "git@host:user/name-of-plugin.git", {tag, "1.0.0"}}}
]}.

$ rebar3 plugin_name
===> Fetching plugin_name
===> Compiling plugin_name
<PLUGIN OUTPUT>

-module(provider_template).
-behaviour(provider).

-export([init/1, do/1, format_error/1]).

%% ===================================================================
%% Public API
%% ===================================================================

%% Called when rebar3 first boots, before even parsing the arguments
%% or commands to be run. Purely initiates the provider, and nothing
%% else should be done here.
-spec init(rebar_state:t()) -> {ok, rebar_state:t()}.
init(State) ->
    Provider = providers:create([Options]),
    {ok, rebar_state:add_provider(State, Provider)}.

%% Run the code for the plugin. The command line argument are parsed
%% and dependencies have been run.
-spec do(rebar_state:t()) -> {ok, rebar_state:t()} | {error, string()}.
do(State) ->
    {ok, State}.

%% When an exception is raised or a value returned as
%% `{error, {?MODULE, Reason}}` will see the `format_error(Reason)`
%% function called for them, so a string can be formatted explaining
%% the issue.
-spec format_error(any()) -> iolist().
format_error(Reason) ->
    io_lib:format("~p", [Reason]).

→ rebar3 new plugin todo desc="example rebar3 plugin"
...
→ cd todo
→ git init
Initialized empty Git repository in /Users/ferd/code/self/todo/.git/

-module(todo_prv).
-behaviour(provider).

-export([init/1, do/1, format_error/1]).

-define(PROVIDER, todo).
-define(DEPS, [app_discovery]).

%% ===================================================================
%% Public API
%% ===================================================================
-spec init(rebar_state:t()) -> {ok, rebar_state:t()}.
init(State) ->
    Provider = providers:create([
            {name, ?PROVIDER},          % The 'user friendly' name of the task
            {module, ?MODULE},          % The module implementation of the task
            {bare, true},               % The task can be run by the user, always true
            {deps, ?DEPS},              % The list of dependencies
            {example, "rebar provider_todo"}, % How to use the plugin
            {opts, []}                  % list of options understood by the plugin
            {short_desc, "example rebar3 plugin"},
            {desc, ""}
    ]),
    {ok, rebar_state:add_provider(State, Provider)}.


-spec do(rebar_state:t()) -> {ok, rebar_state:t()} | {error, string()}.
do(State) ->
    {ok, State}.

-spec format_error(any()) -> iolist().
format_error(Reason) ->
    io_lib:format("~p", [Reason]).

Provider = providers:create([
            {name, ?PROVIDER},       % The 'user friendly' name of the task
            {module, ?MODULE},       % The module implementation of the task
            {bare, true},            % The task can be run by the user, always true
            {deps, ?DEPS},           % The list of dependencies
            {example, "rebar todo"}, % How to use the plugin
            {opts, []},              % list of options understood by the plugin
            {short_desc, "Reports TODOs in source code"},
            {desc, "Scans top-level application source and find "
                   "instances of TODO: in commented out content "
                   "to report it to the user."}
    ]),

do(State) ->
    lists:foreach(fun check_todo_app/1, rebar_state:project_apps(State)),
    {ok, State}.

check_todo_app(App) ->
    Paths = rebar_dir:src_dirs(rebar_app_info:opts(App)),
    Mods = find_source_files(Paths),
    case lists:foldl(fun check_todo_mod/2, [], Mods) of
        [] -> ok;
        Instances -> display_todos(rebar_app_info:name(App), Instances)
    end.
find_source_files(Paths) ->
    find_source_files(Paths, []).

find_source_files([], Files) ->
    Files;
find_source_files([Path | Rest], Files) ->
    find_source_files(Rest, [filename:join(Path, Mod) || Mod <- filelib:wildcard("*.erl", Path)] ++ Files).

check_todo_mod(ModPath, Matches) ->
    {ok, Bin} = file:read_file(ModPath),
    case find_todo_lines(Bin) of
        [] -> Matches;
        Lines -> [{ModPath, Lines} | Matches]
    end.

find_todo_lines(File) ->
    case re:run(File, "%+.*(TODO:.*)", [{capture, all_but_first, binary}, global, caseless]) of
        {match, DeepBins} -> lists:flatten(DeepBins);
        nomatch -> []
    end.

display_todos(_, []) -> ok;
display_todos(App, FileMatches) ->
    io:format("Application ~s~n",[App]),
    [begin
      io:format("\t~s~n",[Mod]),
      [io:format("\t  ~s~n",[TODO]) || TODO <- TODOs]
     end || {Mod, TODOs} <- FileMatches],
    ok.

{plugins, [
  {todo, {git, "[email protected]:ferd/rebar3-todo-plugin.git", {branch, "master"}}}
]}.

→ rebar3 todo

===> Fetching todo

===> Compiling todo

Application merklet

    /Users/ferd/code/self/merklet/src/merklet.erl

      todo: consider endianness for absolute portability

-define(DEPS, [install_deps]).

{opts, [                 % list of options understood by the plugin
    {deps, $d, "deps", undefined, "also run against dependencies"}
]},

do(State) ->
    Apps = case discovery_type(State) of
        project -> rebar_state:project_apps(State);
        deps -> rebar_state:project_apps(State) ++ lists:usort(rebar_state:all_deps(State))
    end,
    lists:foreach(fun check_todo_app/1, Apps),
    {ok, State}.

[...]

discovery_type(State) ->
    {Args, _} = rebar_state:command_parsed_args(State),
    case proplists:get_value(deps, Args) of
        undefined -> project;
        _ -> deps
    end.

===> Fetching todo

===> Compiling todo

===> Fetching bootstrap

===> Fetching file_monitor

===> Fetching recon

[...]

Application dirmon

    /Users/ferd/code/self/figsync/apps/dirmon/src/dirmon_tracker.erl

      TODO: Peeranha should expose the UUID from a node.

Application meck

    /Users/ferd/code/self/figsync/_deps/meck/src/meck_proc.erl

      TODO: What to do here?

      TODO: What to do here?

→ rebar3 help todo

Scans top-level application source and find instances of TODO: in commented out content to report it to the user.

Usage: rebar todo [-d]

-module(todo).

-export([init/1]).

-spec init(rebar_state:t()) -> {ok, rebar_state:t()}.
init(State) ->
    %% initialize all commands here
    {ok, State1} = todo_prv:init(State),
    {ok, State2} = todo_other_prv:init(State1),
    {ok, State2}.