1 files changed, 112 insertions, 0 deletions
diff --git a/src/rebar_agent.erl b/src/rebar_agent.erl
new file mode 100644
index 0000000..0432fb8
--- /dev/null
+++ b/src/rebar_agent.erl
@@ -0,0 +1,112 @@
+-module(rebar_agent).
+-export([start_link/1, do/1, do/2]).
+-export([init/1,
+         handle_call/3, handle_cast/2, handle_info/2,
+         code_change/3, terminate/2]).
+
+-include("rebar.hrl").
+
+-record(state, {state,
+                cwd,
+                show_warning=true}).
+
+start_link(State) ->
+    gen_server:start_link({local, ?MODULE}, ?MODULE, State, []).
+
+do(Command) when is_atom(Command) ->
+    gen_server:call(?MODULE, {cmd, Command}, infinity).
+
+do(Namespace, Command) when is_atom(Namespace), is_atom(Command) ->
+    gen_server:call(?MODULE, {cmd, Namespace, Command}, infinity).
+
+init(State) ->
+    {ok, Cwd} = file:get_cwd(),
+    {ok, #state{state=State, cwd=Cwd}}.
+
+handle_call({cmd, Command}, _From, State=#state{state=RState, cwd=Cwd}) ->
+    MidState = maybe_show_warning(State),
+    {Res, NewRState} = run(default, Command, RState, Cwd),
+    {reply, Res, MidState#state{state=NewRState}};
+handle_call({cmd, Namespace, Command}, _From, State = #state{state=RState, cwd=Cwd}) ->
+    MidState = maybe_show_warning(State),
+    {Res, NewRState} = run(Namespace, Command, RState, Cwd),
+    {reply, Res, MidState#state{state=NewRState}};
+handle_call(_Call, _From, State) ->
+    {noreply, State}.
+
+handle_cast(_Cast, State) ->
+    {noreply, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+run(Namespace, Command, RState, Cwd) ->
+    try
+        case file:get_cwd() of
+            {ok, Cwd} ->
+                Args = [atom_to_list(Namespace), atom_to_list(Command)],
+                CmdState0 = refresh_state(RState, Cwd),
+                CmdState1 = rebar_state:set(CmdState0, task, atom_to_list(Command)),
+                CmdState = rebar_state:set(CmdState1, caller, api),
+                case rebar3:run(CmdState, Args) of
+                    {ok, TmpState} ->
+                        refresh_paths(TmpState),
+                        {ok, CmdState};
+                    {error, Err} when is_list(Err) ->
+                        refresh_paths(CmdState),
+                        {{error, lists:flatten(Err)}, CmdState};
+                    {error, Err} ->
+                        refresh_paths(CmdState),
+                        {{error, Err}, CmdState}
+                end;
+            _ ->
+                {{error, cwd_changed}, RState}
+        end
+    catch
+        Type:Reason ->
+            ?DEBUG("Agent Stacktrace: ~p", [erlang:get_stacktrace()]),
+            {{error, {Type, Reason}}, RState}
+    end.
+
+maybe_show_warning(S=#state{show_warning=true}) ->
+    ?WARN("This feature is experimental and may be modified or removed at any time.", []),
+    S#state{show_warning=false};
+maybe_show_warning(State) ->
+    State.
+
+refresh_paths(RState) ->
+    ToRefresh = (rebar_state:code_paths(RState, all_deps)
+                 ++ [filename:join([rebar_app_info:out_dir(App), "test"])
+                     || App <- rebar_state:project_apps(RState)]
+                %% make sure to never reload self; halt()s the VM
+                ) -- [filename:dirname(code:which(?MODULE))],
+    %% Similar to rebar_utils:update_code/1, but also forces a reload
+    %% of used modules.
+    lists:foreach(fun(Path) ->
+            Name = filename:basename(Path, "/ebin"),
+            App = list_to_atom(Name),
+            application:load(App),
+            case application:get_key(App, modules) of
+                undefined ->
+                    code:add_patha(Path),
+                    ok;
+                {ok, Modules} ->
+                    ?DEBUG("reloading ~p from ~s", [Modules, Path]),
+                    code:replace_path(Name, Path),
+                    [begin code:purge(M), code:delete(M), code:load_file(M) end
+                    || M <- Modules]
+            end
+        end, ToRefresh).
+
+refresh_state(RState, _Dir) ->
+    lists:foldl(
+        fun(F, State) -> F(State) end,
+        rebar3:init_config(),
+        [fun(S) -> rebar_state:current_profiles(S, rebar_state:current_profiles(RState)) end]
+    ).