2 files changed, 100 insertions, 2 deletions
diff --git a/src/rebar_core.erl b/src/rebar_core.erl
index cfe040a..c3a8951 100644
--- a/src/rebar_core.erl
+++ b/src/rebar_core.erl
@@ -54,8 +54,13 @@ process_command(State, Command) ->
                 undefined ->
                     %% On the first run (Namespace = undefined), we use the
                     %% unfound command name to be a namespace.
-                    do([{default, do} | TargetProviders],
-                       rebar_state:namespace(State, Command));
+                    case providers:get_providers_by_namespace(Command, Providers) of
+                        [] ->
+                            {error, io_lib:format("Command ~p not found", [Command])};
+                        _ ->
+                            do([{default, do} | TargetProviders],
+                               rebar_state:namespace(State, Command))
+                    end;
                 default ->
                     {error, io_lib:format("Command ~p not found", [Command])};
                 _ ->
diff --git a/test/rebar_namespace_SUITE.erl b/test/rebar_namespace_SUITE.erl
new file mode 100644
index 0000000..40b7238
--- /dev/null
+++ b/test/rebar_namespace_SUITE.erl
@@ -0,0 +1,93 @@
+-module(rebar_namespace_SUITE).
+-compile(export_all).
+-include_lib("common_test/include/ct.hrl").
+-include_lib("eunit/include/eunit.hrl").
+
+all() -> [implicit_compile, default_compile, do_compile,
+          as_default_compile, as_do_compile,
+          notfound, do_notfound, default_notfound, ns_notfound].
+
+init_per_testcase(Case, Config0) ->
+    Config = rebar_test_utils:init_rebar_state(Config0),
+    AppDir = ?config(apps, Config),
+    Name = rebar_test_utils:create_random_name("app1_"++atom_to_list(Case)),
+    Vsn = rebar_test_utils:create_random_vsn(),
+    rebar_test_utils:create_app(AppDir, Name, Vsn, [kernel, stdlib]),
+    [{name, Name} | Config].
+
+end_per_testcase(_, Config) ->
+    Config.
+
+implicit_compile(Config) ->
+    Name = ?config(name, Config),
+    rebar_test_utils:run_and_check(Config, [],
+                                   ["compile"],
+                                   {ok, [{app, Name}]}).
+
+default_compile(Config) ->
+    Name = ?config(name, Config),
+    rebar_test_utils:run_and_check(Config, [],
+                                   ["default","compile"],
+                                   {ok, [{app, Name}]}).
+
+do_compile(Config) ->
+    Name = ?config(name, Config),
+    rebar_test_utils:run_and_check(Config, [],
+                                   ["do", "compile"],
+                                   {ok, [{app, Name}]}).
+
+as_default_compile(Config) ->
+    Name = ?config(name, Config),
+    rebar_test_utils:run_and_check(Config, [],
+                                   ["as", "prod", "default", "compile"],
+                                   {ok, [{app, Name}]}).
+
+as_do_compile(Config) ->
+    Name = ?config(name, Config),
+    rebar_test_utils:run_and_check(Config, [],
+                                   ["as", "prod", "do", "compile"],
+                                   {ok, [{app, Name}]}).
+
+notfound(Config) ->
+    Command = ["fakecommand"],
+    rebar_test_utils:run_and_check(
+      Config, [], Command,
+      {error, io_lib:format("Command ~p not found", [fakecommand])}
+    ).
+
+do_notfound(Config) ->
+    Command = ["do", "fakecommand"],
+    rebar_test_utils:run_and_check(
+      Config, [], Command,
+      {error, io_lib:format("Command ~p not found", [fakecommand])}
+    ).
+
+default_notfound(Config) ->
+    Command = ["default", "fakecommand"],
+    rebar_test_utils:run_and_check(
+      Config, [], Command,
+      {error, io_lib:format("Command ~p not found", [fakecommand])}
+    ).
+
+ns_notfound(Config) ->
+    Command = ["ns", "fakecommand"],
+    rebar_test_utils:run_and_check(
+      add_fake_ns_provider(Config), [], Command,
+      {error, io_lib:format("Command ~p not found in namespace ~p",
+                            [fakecommand, ns])}
+    ).
+
+%%% Helpers %%%
+add_fake_ns_provider(Config) ->
+    State = ?config(state, Config),
+    State1 = rebar_state:add_provider(
+      State,
+      providers:create(
+        [{name, fake_provider},
+         {module, fake_provider},
+         {namespace, ns},
+         {deps, []},
+         {opts, []}]
+       )
+     ),
+    [{state, State1} | Config].