Implement resource v2 callback compatibiity

Implement rebar_resource_v2 compatible callbacks in order to make the plugin compatible with all known versions of rebar3, following the guide at https://www.rebar3.org/v3/docs/custom-dep-resources#section-resources-compatible-with-all-versions

src/rebar_raw_resource.erl

@@ -36,11 +36,11 @@
     % provider
     do/1,
     format_error/1,
-    init/1,
+    init/1, init/2,
     % rebar_resource
-    download/3,
+    download/3, download/4,
     lock/2,
-    make_vsn/1,
+    make_vsn/1, make_vsn/2,
     needs_update/2
 ]).
 
@@ -194,10 +194,26 @@
 % download/3 is NOT called first if the dependency is already present, and
 % it's the only resource call that gets to see the rebar state.
 %
+% Note: This arity is the pre-rebar3 3.7.0 format of this function.
+%
 init(State) ->
     #mod_data{} = absorb_state(State),
     {'ok', rebar_state:add_resource(State, {?RTYPE, ?MODULE})}.
 
+-spec init(Type :: rsrc_type(),
+           State :: rebar_state()) -> {'ok', rebar_state()}.
+%
+% Installs the resource handler, the provider itself does nothing.
+%
+% This gets called repeatedly, for each profile, and in each case we want
+% to prime the process environment with any info we may need later, as
+% download/3 is NOT called first if the dependency is already present, and
+% it's the only resource call that gets to see the rebar state.
+%
+init(Type, State) ->
+    #mod_data{} = absorb_state(State),
+    {'ok', rebar_resource_v2:new(Type, ?MODULE, State)}.
+
 -spec do(State :: rebar_state:t()) -> {'ok', rebar_state()}.
 %
 % Fulfills the `provider' contract, does nothing ... for now.
@@ -225,11 +241,13 @@ format_error(Error) ->
 %% Resource API
 %% ===================================================================
 
--spec download(
-    Dest :: rsrc_dir(), From :: this_spec(), State :: rebar_state())
-        -> {'ok', term()} | rebar_err().
+-spec download(Dest :: rsrc_dir(),
+               From :: this_spec(),
+               State :: rebar_state())
+              -> {'ok', term()} | rebar_err().
 %
 % Download the specified resource using its underlying handler.
+% Note: This arity is the pre-rebar3 3.7.0 format of this function.
 %
 download(Dest, {?RTYPE, Loc,
         #mod_ref{res = Res, ref = Ref, opt = Opts}}, State) ->
@@ -254,42 +272,72 @@ download(Dest, {?RTYPE, Spec, Opts}, State) ->
             Err
     end.
 
--spec lock(Path :: rsrc_dir(), Spec :: this_spec())
-        -> rebar_lock() | no_return().
+-spec download(Dest :: rsrc_dir(),
+               AppInfo :: rebar_app_info:t(),
+               ResourceState :: term(),
+               State :: rebar_state())
+              -> {'ok', term()} | rebar_err().
+%
+% Download the specified resource using its underlying handler.
+%
+download(TmpDir, AppInfo, _ResourceState, RebarState) ->
+    download(TmpDir, rebar_app_info:source(AppInfo), RebarState).
+
+-spec lock(Path :: rsrc_dir(),
+           Spec :: this_spec())
+          -> rebar_lock() | no_return();
+          (AppInfo :: rebar_app_info:t(),
+           ResourceState :: term())
+          -> rebar_lock() | no_return().
 %
 % Pass through to the underlying resource handler.
 % Note that the callback doesn't allow an error tuple to be returned, so an
 % exception is our only option if we can't look up the mapping.
 %
-lock(Path, {?RTYPE, Loc, #mod_ref{res = Res, ref = Prev} = Rec}) ->
+%% pre-rebar3 3.7.0 format
+lock(Path, Source) when not(erlang:is_tuple(Path)) ->
+    lock_(Path, Source);
+%% rebar_resource_v2 format
+lock(AppInfo, _ResourceState) ->
+    %%    extract info for dir         extract info for source
+    lock_(rebar_app_info:dir(AppInfo), rebar_app_info:source(AppInfo)).
+
+lock_(Path, {?RTYPE, Loc, #mod_ref{res = Res, ref = Prev} = Rec}) ->
     #mod_res{mod = Mod} = lookup_res(mod_data(), Res),
     {Res, Loc, Ref} = Mod:lock(Path, {Res, Loc, Prev}),
     {?RTYPE, Loc, Rec#mod_ref{ref = Ref}};
 
-lock(Path, {?RTYPE, Spec}) ->
-    lock(Path, {?RTYPE, Spec, []});
+lock_(Path, {?RTYPE, Spec}) ->
+    lock_(Path, {?RTYPE, Spec, []});
 
-lock(Path, {?RTYPE, Spec, Opts}) ->
+lock_(Path, {?RTYPE, Spec, Opts}) ->
     {Res, _} = parse_ext_spec(Spec),
     #mod_res{mod = Mod} = lookup_res(mod_data(), Res),
     {Res, Loc, Ref} = Mod:lock(Path, Spec),
     {?RTYPE, Loc, #mod_ref{res = Res, ref = Ref, opt = Opts}}.
 
--spec needs_update(Path :: rsrc_dir(), Spec :: this_spec())
+-spec needs_update(Path :: rsrc_dir(), SpecOrResourceState :: this_spec())
         -> boolean() | no_return().
 %
 % Pass through to the underlying resource handler.
 % Note that the callback doesn't allow an error tuple to be returned, so an
 % exception is our only option if we can't look up the mapping.
 %
-needs_update(Path, {?RTYPE, Loc, #mod_ref{res = Res, ref = Ref}}) ->
+%% pre-rebar3 3.7.0 format
+needs_update(Dir, {_Type, _Path, _Ref} = Spec) ->
+    needs_update_(Dir, Spec);
+%% rebar_resource_v2 compatible format
+needs_update(AppInfo, _ResourceState) ->
+    needs_update_(rebar_app_info:dir(AppInfo), rebar_app_info:source(AppInfo)).
+
+needs_update_(Path, {?RTYPE, Loc, #mod_ref{res = Res, ref = Ref}}) ->
     #mod_res{mod = Mod} = lookup_res(mod_data(), Res),
     Mod:needs_update(Path, {Res, Loc, Ref});
 
-needs_update(Path, {?RTYPE, Spec, _}) ->
-    needs_update(Path, {?RTYPE, Spec});
+needs_update_(Path, {?RTYPE, Spec, _}) ->
+    needs_update_(Path, {?RTYPE, Spec});
 
-needs_update(Path, {?RTYPE, Spec}) ->
+needs_update_(Path, {?RTYPE, Spec}) ->
     {Res, _} = parse_ext_spec(Spec),
     #mod_res{mod = Mod} = lookup_res(mod_data(), Res),
     Mod:needs_update(Path, Spec).
@@ -306,6 +354,16 @@ make_vsn(Path) ->
     #mod_res{mod = Mod} = lookup_res(Data, Res),
     Mod:make_vsn(Path).
 
+-spec make_vsn(Path :: rsrc_dir(),
+               State :: rebar_state())
+              -> rebar_vsn() | {'error', string()} | no_return().
+%
+% Pass through to the underlying resource handler.
+% The weird error tuple spec comes from the rebar_resource behavior.
+%
+make_vsn(Dir, _ResourceState) ->
+    make_vsn(Dir).
+
 %% ===================================================================
 %% Internal
 %% ===================================================================