proposal for testing python_requires explicitly

conan/cli/commands/create.py

@@ -9,7 +9,7 @@
 from conan.cli.printers import print_profiles
 from conan.cli.printers.graph import print_graph_packages, print_graph_basic
 from conan.errors import ConanException
-from conans.util.files import mkdir
+from conans.util.files import mkdir, load
 
 
 @conan_command(group="Creator", formatters={"json": format_graph_json})
@@ -98,13 +98,20 @@ def create(conan_api, parser, *args):
     if test_conanfile_path:
         # TODO: We need arguments for:
         #  - decide update policy "--test_package_update"
-        tested_python_requires = ref.repr_notime() if is_python_require else None
+        # If it is a string, it will be injected always, if it is a RecipeReference, then it will
+        # be replaced only if ``python_requires = "tested_reference_str"``
+        tested_python_requires = ref.repr_notime() if is_python_require else ref
         from conan.cli.commands.test import run_test
         # The test_package do not make the "conan create" command return a different graph or
         # produce a different lockfile. The result is always the same, irrespective of test_package
         run_test(conan_api, test_conanfile_path, ref, profile_host, profile_build, remotes, lockfile,
                  update=False, build_modes=args.build, build_modes_test=args.build_test,
                  tested_python_requires=tested_python_requires, tested_graph=deps_graph)
+        if is_python_require:
+            if 'python_requires = "tested_reference_str"' not in load(test_conanfile_path):
+                ConanOutput().warning("test_package/conanfile.py should declare "
+                                      "'python_requires = \"tested_reference_str\"'",
+                                      warn_tag="deprecated")
 
     conan_api.lockfile.save_lockfile(lockfile, args.lockfile_out, cwd)
     return {"graph": deps_graph,
@@ -124,16 +131,16 @@ def _check_tested_reference_matches(deps_graph, tested_ref, out):
                     "tested is '{}'".format(missmatch[0], tested_ref))
 
 
-def test_package(conan_api, deps_graph, test_conanfile_path, tested_python_requires=None):
+def test_package(conan_api, deps_graph, test_conanfile_path):
     out = ConanOutput()
     out.title("Testing the package")
     # TODO: Better modeling when we are testing a python_requires
-    if len(deps_graph.nodes) == 1 and not tested_python_requires:
+    conanfile = deps_graph.root.conanfile
+    if len(deps_graph.nodes) == 1 and not hasattr(conanfile, "python_requires"):
         raise ConanException("The conanfile at '{}' doesn't declare any requirement, "
                              "use `self.tested_reference_str` to require the "
                              "package being created.".format(test_conanfile_path))
     conanfile_folder = os.path.dirname(test_conanfile_path)
-    conanfile = deps_graph.root.conanfile
     # To make sure the folders are correct
     conanfile.folders.set_base_folders(conanfile_folder, output_folder=None)
     if conanfile.build_folder and conanfile.build_folder != conanfile.source_folder:

conan/cli/commands/test.py

@@ -38,7 +38,7 @@ def test(conan_api, parser, *args):
     print_profiles(profile_host, profile_build)
 
     deps_graph = run_test(conan_api, path, ref, profile_host, profile_build, remotes, lockfile,
-                          args.update, build_modes=args.build)
+                          args.update, build_modes=args.build, tested_python_requires=ref)
     lockfile = conan_api.lockfile.update_lockfile(lockfile, deps_graph, args.lockfile_packages,
                                                   clean=args.lockfile_clean)
     conan_api.lockfile.save_lockfile(lockfile, args.lockfile_out, cwd)
@@ -74,5 +74,5 @@ def run_test(conan_api, path, ref, profile_host, profile_build, remotes, lockfil
 
     conan_api.install.install_binaries(deps_graph=deps_graph, remotes=remotes)
     _check_tested_reference_matches(deps_graph, ref, out)
-    test_package(conan_api, deps_graph, path, tested_python_requires)
+    test_package(conan_api, deps_graph, path)
     return deps_graph

conans/client/loader.py

@@ -54,7 +54,10 @@ def load_basic_module(self, conanfile_path, graph_lock=None, display="", remotes
 
         try:
             module, conanfile = _parse_conanfile(conanfile_path)
-            if tested_python_requires:
+            if isinstance(tested_python_requires, RecipeReference):
+                if getattr(conanfile, "python_requires", None) == "tested_reference_str":
+                    conanfile.python_requires = tested_python_requires.repr_notime()
+            elif tested_python_requires:
                 conanfile.python_requires = tested_python_requires
 
             if self._pyreq_loader:

conans/test/integration/py_requires/python_requires_test.py

@@ -1013,6 +1013,7 @@ class Common(ConanFile):
             from conan import ConanFile
 
             class Tool(ConanFile):
+                python_requires = "tested_reference_str"
                 def test(self):
                     self.output.info("{}!!!".format(self.python_requires["common"].module.mycommon()))
             """)
@@ -1021,6 +1022,9 @@ def test(self):
         c.run("create .")
         assert "common/0.1 (test package): 42!!!" in c.out
 
+        c.run("test test_package common/0.1")
+        assert "common/0.1 (test package): 42!!!" in c.out
+
     def test_test_package_python_requires_configs(self):
         """ test how to test_package a python_require with various configurations
         """
@@ -1048,6 +1052,7 @@ def test(self):
                 "test_package/conanfile.py": test})
         c.run("create . ")
         assert "common/0.1 (test package): RELEASEOK!!!" in c.out
+        assert "WARN: deprecated: test_package/conanfile.py should declare 'python_requires" in c.out
         c.run("create . -s build_type=Debug")
         assert "common/0.1 (test package): DEBUGOK!!!" in c.out