Adding config file for stubtest.py (python#9203)

pikachu · web-flow · commit 7938f5d0025b · 2020-08-04T00:46:31.000-07:00
diff --git a/mypy/stubtest.py b/mypy/stubtest.py
@@ -23,6 +23,7 @@
 import mypy.modulefinder
 import mypy.types
 from mypy import nodes
+from mypy.config_parser import parse_config_file
 from mypy.options import Options
 from mypy.util import FancyFormatter
 
@@ -1040,6 +1041,12 @@ def test_stubs(args: argparse.Namespace) -> int:
     options = Options()
     options.incremental = False
     options.custom_typeshed_dir = args.custom_typeshed_dir
+    options.config_file = args.mypy_config_file
+
+    if options.config_file:
+        def set_strict_flags() -> None:  # not needed yet
+            return
+        parse_config_file(options, set_strict_flags, options.config_file, sys.stdout, sys.stderr)
 
     try:
         modules = build_stubs(modules, options, find_submodules=not args.check_typeshed)
@@ -1133,6 +1140,19 @@ def parse_options(args: List[str]) -> argparse.Namespace:
         action="store_true",
         help="Ignore unused whitelist entries",
     )
+    config_group = parser.add_argument_group(
+        title='mypy config file',
+        description="Use a config file instead of command line arguments. "
+                    "Plugins and mypy path are the only supported "
+                    "configurations.",
+    )
+    config_group.add_argument(
+        '--mypy-config-file',
+        help=(
+            "An existing mypy configuration file, currently used by stubtest to help "
+            "determine mypy path and plugins"
+        ),
+    )
 
     return parser.parse_args(args)
 
diff --git a/mypy/test/teststubtest.py b/mypy/test/teststubtest.py
@@ -11,6 +11,7 @@
 
 import mypy.stubtest
 from mypy.stubtest import parse_options, test_stubs
+from mypy.test.data import root_dir
 
 
 @contextlib.contextmanager
@@ -27,13 +28,18 @@ def use_tmp_dir() -> Iterator[None]:
 TEST_MODULE_NAME = "test_module"
 
 
-def run_stubtest(stub: str, runtime: str, options: List[str]) -> str:
+def run_stubtest(
+    stub: str, runtime: str, options: List[str], config_file: Optional[str] = None,
+) -> str:
     with use_tmp_dir():
         with open("{}.pyi".format(TEST_MODULE_NAME), "w") as f:
             f.write(stub)
         with open("{}.py".format(TEST_MODULE_NAME), "w") as f:
             f.write(runtime)
-
+        if config_file:
+            with open("{}_config.ini".format(TEST_MODULE_NAME), "w") as f:
+                f.write(config_file)
+            options = options + ["--mypy-config-file", "{}_config.ini".format(TEST_MODULE_NAME)]
         if sys.path[0] != ".":
             sys.path.insert(0, ".")
         if TEST_MODULE_NAME in sys.modules:
@@ -753,3 +759,18 @@ class StubtestIntegration(unittest.TestCase):
     def test_typeshed(self) -> None:
         # check we don't crash while checking typeshed
         test_stubs(parse_options(["--check-typeshed"]))
+
+    def test_config_file(self) -> None:
+        runtime = "temp = 5\n"
+        stub = "from decimal import Decimal\ntemp: Decimal\n"
+        config_file = (
+            "[mypy]\n"
+            "plugins={}/test-data/unit/plugins/decimal_to_int.py\n".format(root_dir)
+        )
+        output = run_stubtest(stub=stub, runtime=runtime, options=[])
+        assert output == (
+            "error: test_module.temp variable differs from runtime type Literal[5]\n"
+            "Stub: at line 2\ndecimal.Decimal\nRuntime:\n5\n\n"
+        )
+        output = run_stubtest(stub=stub, runtime=runtime, options=[], config_file=config_file)
+        assert output == ""
diff --git a/test-data/unit/plugins/decimal_to_int.py b/test-data/unit/plugins/decimal_to_int.py
@@ -0,0 +1,18 @@
+import builtins
+from typing import Optional, Callable
+
+from mypy.plugin import Plugin, AnalyzeTypeContext
+from mypy.types import CallableType, Type
+
+
+class MyPlugin(Plugin):
+    def get_type_analyze_hook(self, fullname):
+        if fullname == "decimal.Decimal":
+            return decimal_to_int_hook
+        return None
+
+def plugin(version):
+    return MyPlugin
+
+def decimal_to_int_hook(ctx):
+    return ctx.api.named_type('builtins.int', [])
