Revert "Revert "support native types in macros""

This reverts commit 84c1836.

src/jinja2/compiler.py

@@ -724,6 +724,7 @@ def write_commons(self) -> None:
         """
         self.writeline("resolve = context.resolve_or_missing")
         self.writeline("undefined = environment.undefined")
+        self.writeline("concat = environment.concat")
         # always use the standard Undefined class for the implicit else of
         # conditional expressions
         self.writeline("cond_expr_undefined = Undefined")

src/jinja2/environment.py

@@ -283,6 +283,8 @@ class Environment:
     #: :class:`~jinja2.compiler.CodeGenerator` for more information.
     code_generator_class: t.Type["CodeGenerator"] = CodeGenerator
 
+    concat = "".join
+
     #: the context class that is used for templates.  See
     #: :class:`~jinja2.runtime.Context` for more information.
     context_class: t.Type[Context] = Context
@@ -1296,7 +1298,7 @@ def render(self, *args: t.Any, **kwargs: t.Any) -> str:
         ctx = self.new_context(dict(*args, **kwargs))
 
         try:
-            return concat(self.root_render_func(ctx))  # type: ignore
+            return self.environment.concat(self.root_render_func(ctx))  # type: ignore
         except Exception:
             self.environment.handle_exception()
 
@@ -1317,7 +1319,9 @@ async def render_async(self, *args: t.Any, **kwargs: t.Any) -> str:
         ctx = self.new_context(dict(*args, **kwargs))
 
         try:
-            return concat([n async for n in self.root_render_func(ctx)])  # type: ignore
+            return self.environment.concat(  # type: ignore
+                [n async for n in self.root_render_func(ctx)]  # type: ignore
+            )
         except Exception:
             return self.environment.handle_exception()
 

src/jinja2/nativetypes.py

@@ -3,6 +3,7 @@
 from ast import parse
 from itertools import chain
 from itertools import islice
+from types import GeneratorType
 
 from . import nodes
 from .compiler import CodeGenerator
@@ -31,7 +32,9 @@ def native_concat(values: t.Iterable[t.Any]) -> t.Optional[t.Any]:
         if not isinstance(raw, str):
             return raw
     else:
-        raw = "".join([str(v) for v in chain(head, values)])
+        if isinstance(values, GeneratorType):
+            values = chain(head, values)
+        raw = "".join([str(v) for v in values])
 
     try:
         return literal_eval(
@@ -86,6 +89,7 @@ class NativeEnvironment(Environment):
     """An environment that renders templates to native Python types."""
 
     code_generator_class = NativeCodeGenerator
+    concat = staticmethod(native_concat)  # type: ignore
 
 
 class NativeTemplate(Template):
@@ -101,7 +105,9 @@ def render(self, *args: t.Any, **kwargs: t.Any) -> t.Any:
         ctx = self.new_context(dict(*args, **kwargs))
 
         try:
-            return native_concat(self.root_render_func(ctx))  # type: ignore
+            return self.environment_class.concat(  # type: ignore
+                self.root_render_func(ctx)  # type: ignore
+            )
         except Exception:
             return self.environment.handle_exception()
 
@@ -114,7 +120,7 @@ async def render_async(self, *args: t.Any, **kwargs: t.Any) -> t.Any:
         ctx = self.new_context(dict(*args, **kwargs))
 
         try:
-            return native_concat(
+            return self.environment_class.concat(  # type: ignore
                 [n async for n in self.root_render_func(ctx)]  # type: ignore
             )
         except Exception:

src/jinja2/runtime.py

@@ -49,7 +49,6 @@ def __call__(
     "Markup",
     "TemplateRuntimeError",
     "missing",
-    "concat",
     "escape",
     "markup_join",
     "str_join",

tests/test_nativetypes.py

@@ -168,3 +168,10 @@ def test_leading_spaces(env):
     t = env.from_string(" {{ True }}")
     result = t.render()
     assert result == " True"
+
+
+def test_macro(env):
+    t = env.from_string("{%- macro x() -%}{{- [1,2] -}}{%- endmacro -%}{{- x()[1] -}}")
+    result = t.render()
+    assert result == 2
+    assert isinstance(result, int)