feat(zipapp): Add python_zip_file output group for better compatibility (#3574)

The original zipapp functionality exposed the plain, non-executable
zipapp zip file
using the `python_zip_file` output group. This is easy to support, so
add it to
make it more compatible and easier to switch over.

Along the way ...
* Add some versionadded markers
* Add zipapp_rules to features.bzl

Work towards #2586

Author: rickeylev

python/features.bzl

@@ -63,6 +63,14 @@ def _features_typedef():
     optional trailing `-rcN`. For unreleased versions, it is an empty string.
     :::{versionadded} 0.38.0
     ::::
+
+    ::::{field} zipapp_rules
+    :type: bool
+
+    Whether the rules_python version has the `py_zipapp_*` rules
+
+    :::{versionadded} VERSION_NEXT_FEATURE
+    ::::
     """
 
 features = struct(
@@ -73,4 +81,5 @@ features = struct(
     py_info_venv_symlinks = True,
     uses_builtin_rules = False,
     version = _VERSION_PRIVATE if "$Format" not in _VERSION_PRIVATE else "",
+    zipapp_rules = True,
 )

python/private/zipapp/py_zipapp_rule.bzl

@@ -218,6 +218,9 @@ def _py_zipapp_executable_impl(ctx):
             runfiles = ctx.runfiles(files = default_outputs),
             executable = executable,
         ),
+        OutputGroupInfo(
+            python_zip_file = depset([zip_file]),
+        ),
     ]
 
 def _transition_zipapp_impl(settings, attr):
@@ -325,10 +328,25 @@ Whether the output should be an executable zip file.
 
 _TOOLCHAINS = [EXEC_TOOLS_TOOLCHAIN_TYPE] + ([LAUNCHER_MAKER_TOOLCHAIN_TYPE] if rp_config.bazel_9_or_later else [])
 
+_COMMON_RULE_DOC = """
+
+Output groups:
+
+* `python_zip_file`: (*deprecated*) The plain, non-self-executable zipapp zipfile.
+  *This output group is deprecated and retained for compatibility with
+  the previous implicit zipapp functionality. Set `executable=False`
+  and use the default output of the target instead.*
+
+:::{versionadded} VERSION_NEXT_FEATURE
+:::
+""".lstrip()
+
 py_zipapp_binary = rule(
     doc = """
 Packages a `py_binary` as a Python zipapp.
-""",
+
+{}
+""".format(_COMMON_RULE_DOC),
     implementation = _py_zipapp_executable_impl,
     attrs = _ATTRS,
     # NOTE: While this is marked executable, it is conditionally executable
@@ -343,7 +361,9 @@ py_zipapp_test = rule(
 Packages a `py_test` as a Python zipapp.
 
 This target is also a valid test target to run.
-""",
+
+{}
+""".format(_COMMON_RULE_DOC),
     implementation = _py_zipapp_executable_impl,
     attrs = _ATTRS,
     # NOTE: While this is marked as a test, it is conditionally executable

python/zipapp/py_zipapp_binary.bzl

@@ -1,11 +1,20 @@
-"""`py_zipapp_binary` macro."""
+"""`py_zipapp_binary` macro.
+
+:::{seealso}
+
+{obj}`features.zipapp_rules` to detect if this rule is available.
+:::
+"""
 
 load("//python/private:util.bzl", "add_tag")
 load("//python/private/zipapp:py_zipapp_rule.bzl", _py_zipapp_binary_rule = "py_zipapp_binary")
 
 def py_zipapp_binary(**kwargs):
     """Builds a Python zipapp from a py_binary/py_test target.
 
+    :::{versionadded} VERSION_NEXT_FEATURE
+    :::
+
     Args:
         **kwargs: Args passed onto {rule}`py_zipapp_binary`.
     """

python/zipapp/py_zipapp_test.bzl

@@ -1,11 +1,20 @@
-"""`py_zipapp_test` macro."""
+"""`py_zipapp_test` macro.
+
+:::{seealso}
+
+{obj}`features.zipapp_rules` to detect if this rule is available.
+:::
+"""
 
 load("//python/private:util.bzl", "add_tag")
 load("//python/private/zipapp:py_zipapp_rule.bzl", _py_zipapp_test = "py_zipapp_test")
 
 def py_zipapp_test(**kwargs):
     """Builds a Python zipapp from a py_binary/py_test target.
 
+    :::{versionadded} VERSION_NEXT_FEATURE
+    :::
+
     Args:
         **kwargs: Args passed onto {rule}`py_zipapp_test`.
     """