Increases toolchain.py test coverage

Increases `test_create()` coverage demonstrating crash referenced in:
<kivy#1867 (comment)>
Adds `test_recipes()` checking if it prints out without crashing.

pythonforandroid/toolchain.py

@@ -739,6 +739,15 @@ def _read_configuration():
                 sys.argv.append(arg)
 
     def recipes(self, args):
+        """
+        Prints recipes basic info, e.g.
+        ```
+        python3      3.7.1
+            depends: ['hostpython3', 'sqlite3', 'openssl', 'libffi']
+            conflicts: ['python2']
+            optional depends: ['sqlite3', 'libffi', 'openssl']
+        ```
+        """
         ctx = self.ctx
         if args.compact:
             print(" ".join(set(Recipe.list_recipes(ctx))))

tests/test_toolchain.py

@@ -1,3 +1,4 @@
+import io
 import sys
 import pytest
 import mock
@@ -13,6 +14,10 @@ def patch_argparse_print_help():
     return mock.patch('argparse.ArgumentParser.print_help')
 
 
+def patch_sys_stdout():
+    return mock.patch('sys.stdout', new_callable=io.StringIO)
+
+
 def raises_system_exit():
     return pytest.raises(SystemExit)
 
@@ -51,6 +56,8 @@ def test_create(self):
             'create',
             '--sdk-dir=/tmp/android-sdk',
             '--ndk-dir=/tmp/android-ndk',
+            '--bootstrap=service_only',
+            '--requirements=python3',
             '--dist-name=test_toolchain',
         ]
         with patch_sys_argv(argv), mock.patch(
@@ -62,8 +69,11 @@ def test_create(self):
         ) as m_get_ndk_platform_dir, mock.patch(
             'pythonforandroid.build.get_cython_path'
         ) as m_get_cython_path, mock.patch(
-            'pythonforandroid.toolchain.build_dist_from_args'
-        ) as m_build_dist_from_args:
+            'pythonforandroid.toolchain.build_recipes'
+        ) as m_build_recipes, mock.patch(
+            'pythonforandroid.bootstraps.service_only.'
+            'ServiceOnlyBootstrap.run_distribute'
+        ) as m_run_distribute:
             m_get_available_apis.return_value = [27]
             m_get_toolchain_versions.return_value = (['4.9'], True)
             m_get_ndk_platform_dir.return_value = (
@@ -74,16 +84,52 @@ def test_create(self):
         assert m_get_toolchain_versions.call_args_list == [
             mock.call('/tmp/android-ndk', mock.ANY)]
         assert m_get_cython_path.call_args_list == [mock.call()]
-        assert m_build_dist_from_args.call_count == 1
+        build_order = [
+            'hostpython3', 'libffi', 'openssl', 'sqlite3', 'python3',
+            'genericndkbuild', 'setuptools', 'six', 'pyjnius', 'android',
+        ]
+        python_modules = []
+        context = mock.ANY
+        project_dir = None
+        assert m_build_recipes.call_args_list == [
+            mock.call(
+                build_order,
+                python_modules,
+                context,
+                project_dir,
+                ignore_project_setup_py=False
+            )
+        ]
+        assert m_run_distribute.call_args_list == [mock.call()]
 
     def test_create_no_sdk_dir(self):
         """
         The `--sdk-dir` is mandatory to `create` a distribution.
         """
         argv = ['toolchain.py', 'create']
-        with mock.patch('sys.argv', argv), pytest.raises(
+        with patch_sys_argv(argv), pytest.raises(
             BuildInterruptingException
         ) as ex_info:
             ToolchainCL()
         assert ex_info.value.message == (
             'Android SDK dir was not specified, exiting.')
+
+    @pytest.mark.skipif(sys.version_info < (3, 0), reason="requires python3")
+    def test_recipes(self):
+        """
+        Checks the `recipes` command prints out recipes information without crashing.
+        """
+        argv = ['toolchain.py', 'recipes']
+        with patch_sys_argv(argv), patch_sys_stdout() as m_stdout:
+            ToolchainCL()
+        # check if we have common patterns in the output
+        expected_strings = (
+            'conflicts:',
+            'depends:',
+            'kivy',
+            'optional depends:',
+            'python3',
+            'sdl2',
+        )
+        for expected_string in expected_strings:
+            assert expected_string in m_stdout.getvalue()