Merge pull request #52 from soranoba/nil-and-empty-string-as-false

Treat nil and empty binaries as false in conditions

Author: soranoba

src/bbmustache.erl

@@ -287,7 +287,7 @@ compile_impl([{'#', Keys, Tags, Source} | T], Data, Result, State) ->
       _ when is_list(Value) ->
             compile_impl(T, Data, lists:foldl(fun(X, Acc) -> compile_impl(Tags, X, Acc, NestedState) end,
                                              Result, Value), State);
-      _ when Value =:= false ->
+      _ when Value =:= false; Value =:= nil; Value =:= <<"">> ->
             compile_impl(T, Data, Result, State);
       _ when is_function(Value, 2) ->
             Ret = Value(Source, fun(Text) -> render(Text, Data, State#?MODULE.options) end),
@@ -297,7 +297,7 @@ compile_impl([{'#', Keys, Tags, Source} | T], Data, Result, State) ->
     end;
 compile_impl([{'^', Keys, Tags} | T], Data, Result, State) ->
     Value = get_data_recursive(Keys, Data, false, State),
-    case Value =:= [] orelse Value =:= false of
+    case Value =:= [] orelse Value =:= false orelse Value =:= nil orelse Value =:= <<"">> of
         true  -> compile_impl(T, Data, compile_impl(Tags, Data, Result, State), State);
         false -> compile_impl(T, Data, Result, State)
     end;

test/bbmustache_tests.erl

@@ -218,6 +218,22 @@ context_stack_test_() ->
                                       [raise_on_context_miss]))}
     ].
 
+shows_or_hides_content_test_() ->
+    [
+     {"It hides content in # tag that is specified as empty list, empty binary, nil or false",
+      fun() ->
+        lists:foreach(fun(X) ->
+          ?assertEqual(<<"">>, bbmustache:render(<<"{{#content}}hello world{{/content}}">>, [{"content", X}]))
+        end, ["", <<"">>, nil, false])
+      end},
+     {"It show content in ^ tag that is specified as empty list, empty binary, nil or false",
+      fun() ->
+        lists:foreach(fun(X) ->
+          ?assertEqual(<<"hello world">>, bbmustache:render(<<"{{^content}}hello world{{/content}}">>, [{"content", X}]))
+        end, ["", <<"">>, nil, false])
+      end}
+    ].
+
 escape_fun_test_() ->
     [
      {"It is able to specified own escape function",