use git or hg configs if exist for default user and email in templates

src/rebar_templater.erl

@@ -132,14 +132,41 @@ override_vars([{Var, Default, Doc} | Rest], General) ->
 
 %% Default variables, generated dynamically.
 default_variables() ->
+    {DefaultAuthor, DefaultEmail} = default_author_and_email(),
     {{Y,M,D},{H,Min,S}} = calendar:universal_time(),
     [{date, lists:flatten(io_lib:format("~4..0w-~2..0w-~2..0w",[Y,M,D]))},
      {datetime, lists:flatten(io_lib:format("~4..0w-~2..0w-~2..0wT~2..0w:~2..0w:~2..0w+00:00",[Y,M,D,H,Min,S]))},
-     {author_name, "Anonymous"},
-     {author_email, "anonymous@example.org"},
+     {author_name, DefaultAuthor},
+     {author_email, DefaultEmail},
      {copyright_year, integer_to_list(Y)},
      {apps_dir, "apps", "Directory where applications will be created if needed"}].
 
+default_author_and_email() ->
+    %% See if we can get a git user and email to use as defaults
+    case rebar_utils:sh("git config --global user.name", []) of
+        {ok, Name} ->
+            case rebar_utils:sh("git config --global user.email", []) of
+                {ok, Email} ->
+                    {string:strip(Name, both, $\n), string:strip(Email, both, $\n)};
+                {error, _} ->
+                    %% Use neither if one doesn't exist
+                    {"Anonymous", "anonymous@example.org"}
+            end;
+        {error, _} ->
+            %% Ok, try mecurial
+            case rebar_utils:sh("hg showconfig ui.username", []) of
+                {ok, NameEmail} ->
+                    case re:run(NameEmail, [{capture, [1,2], list}]) of
+                        {match, [Name, Email]} ->
+                            {Name, Email};
+                        _ ->
+                            {"Anonymous", "anonymous@example.org"}
+                    end;
+                {error, _} ->
+                    {"Anonymous", "anonymous@example.org"}
+            end
+    end.
+
 %% Load variable definitions from the 'Globals' file in the home template
 %% directory
 global_variables(State) ->

test/rebar_new_SUITE.erl

@@ -6,7 +6,7 @@
 -include_lib("common_test/include/ct.hrl").
 -include_lib("eunit/include/eunit.hrl").
 
-all() -> [app].
+all() -> [app, app_with_fallbacks].
 
 
 init_per_testcase(Case, Config0) ->
@@ -32,6 +32,10 @@ mock_empty_escript_templates() ->
     meck:expect(rebar_utils, escript_foldl, fun(_,_,_) -> {ok, []} end).
 
 app(Config) ->
+    meck:expect(rebar_utils, sh, fun("git config --global user.name", _) -> {ok, "gitname"};
+                                    ("git config --global user.email", _) -> {ok, "git@email.com"}
+                                 end),
+
     Name = ?config(name, Config),
     rebar_test_utils:run_and_check(
         Config, [],
@@ -40,7 +44,7 @@ app(Config) ->
     ),
     validate_files(
         Config, Name,
-        [{"LICENSE", ["some_name", "anonymous@example.org"]},
+        [{"LICENSE", ["some_name", "git@email.com"]},
          {"README.md", [Name]},
          {".gitignore", []},
          {"rebar.config", []},
@@ -49,6 +53,26 @@ app(Config) ->
          {filename:join(["src", Name++"_app.erl"]), [Name]}
         ]).
 
+app_with_fallbacks(Config) ->
+    meck:expect(rebar_utils, sh, fun(_, _) -> {error, fallback} end),
+
+    Name = ?config(name, Config),
+    rebar_test_utils:run_and_check(
+      Config, [],
+      ["new", "test_app", Name],
+      {ok, []}
+     ),
+    validate_files(
+      Config, Name,
+      [{"LICENSE", ["Anonymous", "anonymous@example.org"]},
+       {"README.md", [Name]},
+       {".gitignore", []},
+       {"rebar.config", []},
+       {filename:join(["src", Name++".app.src"]), [Name]},
+       {filename:join(["src", Name++"_sup.erl"]), [Name]},
+       {filename:join(["src", Name++"_app.erl"]), [Name]}
+      ]).
+
 validate_files(_Config, Name, Checks) ->
     [begin
         Path = filename:join([Name, File]),