From: Ulf Wiger <ulf@feuerlabs.com>

Date: Fri, 10 Nov 2017 18:59:07 +0100

Subject: [PATCH] Support expansion of setup modes for find_hooks()

diff --git a/doc/setup.md b/doc/setup.md

index 571bde1..4069f34 100644

--- a/doc/setup.md

+++ b/doc/setup.md

@@ -242,6 +242,21 @@ A suggested convention is:

 - Create tables (or configure schema) at 200

 - Populate the database at 300

+Using the `setup` environment variable `modes`, it is possible to

+define a mode that includes all hooks from different modes.

+The format is `[{M1, [M2,...]}]`. The expansion is done recursively,

+so a mode entry in the right-hand side of a pair can expand into other

+modes. In order to be included in the final list of modes, an expanding

+mode needs to include itself in the right-hand side. For example:

+

+- Applying `a` to `[{a, [b]}]` returns `[b]`

+- Applying `a` to `[{a, [a,b]}]` returns `[a,b]`

+- Applying `a` to `[{a, [a,b]},{b,[c,d]}]` returns `[a,c,d]`

+

+A typical application of this would be `[{test, [normal, test]}]`, where

+starting in the `test` mode would cause all `normal` and all `test` hooks

+to be executed.

+

 ### find_hooks/1 ###

diff --git a/src/setup.erl b/src/setup.erl

index 43a1d0f..329c049 100644

--- a/src/setup.erl

+++ b/src/setup.erl

@@ -980,6 +980,21 @@ main(Args) ->

 %% - Create the database at phase 100

 %% - Create tables (or configure schema) at 200

 %% - Populate the database at 300

+%%

+%% Using the `setup' environment variable `modes', it is possible to

+%% define a mode that includes all hooks from different modes.

+%% The format is `[{M1, [M2,...]}]'. The expansion is done recursively,

+%% so a mode entry in the right-hand side of a pair can expand into other

+%% modes. In order to be included in the final list of modes, an expanding

+%% mode needs to include itself in the right-hand side. For example:

+%%

+%% - Applying `a' to `[{a, [b]}]' returns `[b]'

+%% - Applying `a' to `[{a, [a,b]}]' returns `[a,b]'

+%% - Applying `a' to `[{a, [a,b]},{b,[c,d]}]' returns `[a,c,d]'

+%%

+%% A typical application of this would be `[{test, [normal, test]}]', where

+%% starting in the `test' mode would cause all `normal' and all `test' hooks

+%% to be executed.

 %% @end

 %%

 find_hooks() ->

@@ -996,38 +1011,70 @@ find_hooks(Mode) when is_atom(Mode) ->

 %% @doc Find all setup hooks for `Mode' in `Applications'.

 %% @end

 find_hooks(Mode, Applications) ->

+    find_hooks_(Mode, maybe_expand_mode(Mode), Applications).

+

+maybe_expand_mode(Mode) ->

+    maybe_expand_mode(Mode, app_get_env(setup, modes, [])).

+

+maybe_expand_mode(Mode, Modes) ->

+    maybe_expand_mode(Mode, Modes, ordsets:new()).

+

+maybe_expand_mode(Mode, Modes, Acc) ->

+    case lists:keyfind(Mode, 1, Modes) of

+        {_, Ms} ->

+            Modes1 = lists:keydelete(Mode, 1, Modes),

+            lists:foldl(

+                      fun(M, Acc1) ->

+                              maybe_expand_mode(M, Modes1, Acc1)

+                      end, Acc, Ms);

+        false ->

+            ordsets:add_element(Mode, Acc)

+    end.

+

+find_hooks_(Mode, Modes, Applications) ->

     lists:foldl(

       fun(A, Acc) ->

               case app_get_env(A, '$setup_hooks') of

                   {ok, Hooks} ->

                       lists:foldl(

-                        fun({Mode1, [{_, {_,_,_}}|_] = L}, Acc1)

-                              when Mode1 =:= Mode ->

-                                find_hooks_(Mode, A, L, Acc1);

-                           ({Mode1, [{_, [{_, _, _}|_]}|_] = L}, Acc1)

-                              when Mode1 =:= Mode ->

-                                find_hooks_(Mode, A, L, Acc1);

-                           ({N, {_, _, _} = MFA}, Acc1) when Mode=:=setup ->

-                                orddict:append(N, MFA, Acc1);

-                           ({N, [{_, _, _}|_] = L}, Acc1)

-                              when Mode=:=setup ->

-                                lists:foldl(

-                                  fun(MFA, Acc2) ->

-                                          orddict:append(N, MFA, Acc2)

-                                  end, Acc1, L);

-                           (_, Acc1) ->

-                                Acc1

+                        fun(H, Acc1) ->

+                                f_find_hooks_(H, A, Mode, Modes, Acc1)

                         end, Acc, Hooks);

                   _ ->

                       Acc

               end

       end, orddict:new(), Applications).

-find_hooks_(Mode, A, L, Acc1) ->

+f_find_hooks_(Hook, A, Mode, Modes, Acc) ->

+    IsSetup = lists:member(setup, Modes),

+    case Hook of

+        {Mode1, [{_, {_,_,_}}|_] = L} ->

+            case lists:member(Mode1, Modes) of

+                true -> find_hooks_1(Mode1, A, L, Acc);

+                false -> Acc

+            end;

+        {Mode1, [{_, [{_, _, _}|_]}|_] = L} ->

+            case lists:member(Mode1, Modes) of

+                true -> find_hooks_1(Mode1, A, L, Acc);

+                false -> Acc

+            end;

+        {N, {_, _, _} = MFA} when IsSetup ->

+            orddict:append(N, MFA, Acc);

+        {N, [{_, _, _}|_] = L} when IsSetup ->

+            lists:foldl(

+              fun(MFA, Acc1) ->

+                      orddict:append(N, MFA, Acc1)

+              end, Acc, L);

+        _ ->

+            Acc

+    end.

+

+

+find_hooks_1(Mode, A, L, Acc1) ->

     lists:foldl(

       fun({N, {_,_,_} = MFA}, Acc2) ->

               orddict:append(N, MFA, Acc2);

-         ({N, [{_,_,_}|_] = MFAs}, Acc2) when is_list(MFAs) ->

+         ({N, [{_,_,_}|_] = MFAs}, Acc2) ->

               lists:foldl(

                 fun({_,_,_} = MFA1, Acc3) ->

                         orddict:append(

@@ -1653,11 +1700,26 @@ setup_test_() ->

              application:unload(setup)

      end,

      [

+      ?_test(t_expand_modes()),

       ?_test(t_find_hooks()),

+      ?_test(t_find_hooks_1()),

       ?_test(t_expand_vars()),

       ?_test(t_nested_includes())

      ]}.

+t_expand_modes() ->

+    [a] = maybe_expand_mode(a, []),

+    [a] = maybe_expand_mode(a, [{a, [a]}]),

+    [a,b,c] = maybe_expand_mode(a, [{a, [a,b]},

+                                    {b, [b,c]}]),

+    [b] = maybe_expand_mode(a, [{a, [b]}]),

+    [a,b,c] = maybe_expand_mode(a, [{a, [a,b]},

+                                    {b, [b,c]},

+                                    {c, [c,a]}]),

+    [c,d] = maybe_expand_mode(a, [{a, [b]},

+                                  {b, [c,d]}]),

+    ok.

+

 t_find_hooks() ->

     application:set_env(setup, '$setup_hooks',

                         [{100, [{a, hook, [100,1]},

@@ -1678,6 +1740,36 @@ t_find_hooks() ->

      {200, [{a,hook,[200,1]}]}] = SetupHooks,

     ok.

+t_find_hooks_1() ->

+    application:set_env(setup, modes, [{test, [setup, normal, test]}]),

+    application:set_env(setup, '$setup_hooks',

+                        [{100, [{a, hook, [100,1]},

+                                {a, hook, [100,2]}]},

+                         {200, [{a, hook, [200,1]}]},

+                         {upgrade, [{100, [{a, upgrade_hook, [100,1]}]}]},

+                         {setup, [{100, [{a, hook, [100,3]}]}]},

+                         {normal, [{300, {a, normal_hook, [300,1]}}]},

+                         {test, [{400, {a, test_hook, [400,1]}}]}

+                        ]),

+    NormalHooks = find_hooks(normal),

+    [{300, [{a, normal_hook, [300,1]}]}] = NormalHooks,

+    UpgradeHooks = find_hooks(upgrade),

+    [{100, [{a, upgrade_hook, [100,1]}]}] = UpgradeHooks,

+    SetupHooks = find_hooks(setup),

+    [{100, [{a,hook,[100,1]},

+            {a,hook,[100,2]},

+            {a,hook,[100,3]}]},

+     {200, [{a,hook,[200,1]}]}] = SetupHooks,

+    TestHooks = find_hooks(test),

+    [{100, [{a,hook,[100,1]},

+            {a,hook,[100,2]},

+            {a,hook,[100,3]}]},

+     {200, [{a,hook,[200,1]}]},

+     {300, [{a,normal_hook, [300,1]}]},

+     {400, [{a,test_hook, [400,1]}]}] = TestHooks,

+     ok.

+

+

 t_expand_vars() ->

     %% global env

     application:set_env(setup, vars, [{"PLUS", {apply,erlang,'+',[1,2]}},