Set python_version to default to sys.version_info (#4686)

This sets the default Python version used for type checking to `sys.version_info`.

Fixes #4620.

The design of this is such that we set tests to default to the running Python whenever possible, but modify tests that use new syntax and libraries to run on Python 3.5 or 3.6.

Example output of failing tests on 3.4 before test changes https://gist.github.com/ethanhs/f782bec70eab0678d9e869465b40a571#file-output-log-L512.

This was split out of #4403.

Author: emmatyping

mypy/options.py

@@ -52,7 +52,7 @@ def __init__(self) -> None:
 
         # -- build options --
         self.build_type = BuildType.STANDARD
-        self.python_version = defaults.PYTHON3_VERSION
+        self.python_version = sys.version_info[:2]  # type: Tuple[int, int]
         self.platform = sys.platform
         self.custom_typing_module = None  # type: Optional[str]
         self.custom_typeshed_dir = None  # type: Optional[str]

mypy/test/testdiff.py

@@ -5,6 +5,7 @@
 
 from mypy import build
 from mypy.build import BuildSource
+from mypy.defaults import PYTHON3_VERSION
 from mypy.errors import CompileError
 from mypy.nodes import MypyFile
 from mypy.options import Options
@@ -53,6 +54,7 @@ def build(self, source: str) -> Tuple[List[str], Optional[Dict[str, MypyFile]]]:
         options.use_builtins_fixtures = True
         options.show_traceback = True
         options.cache_dir = os.devnull
+        options.python_version = PYTHON3_VERSION
         try:
             result = build.build(sources=[BuildSource('main', None, source)],
                                  options=options,

mypy/test/testmerge.py

@@ -6,6 +6,7 @@
 
 from mypy import build
 from mypy.build import BuildManager, BuildSource, State, Graph
+from mypy.defaults import PYTHON3_VERSION
 from mypy.errors import Errors, CompileError
 from mypy.nodes import (
     Node, MypyFile, SymbolTable, SymbolTableNode, TypeInfo, Expression, Var, TypeVarExpr,
@@ -106,6 +107,7 @@ def build(self, source: str) -> Tuple[List[str], Optional[BuildManager], Dict[st
         options.fine_grained_incremental = True
         options.use_builtins_fixtures = True
         options.show_traceback = True
+        options.python_version = PYTHON3_VERSION
         main_path = os.path.join(test_temp_dir, 'main')
         with open(main_path, 'w') as f:
             f.write(source)

mypy/test/testpythoneval.py

@@ -19,6 +19,7 @@
 
 from typing import List
 
+from mypy.defaults import PYTHON3_VERSION
 from mypy.test.config import test_temp_dir
 from mypy.test.data import DataDrivenTestCase, DataSuite
 from mypy.test.helpers import assert_string_arrays_equal, run_command
@@ -60,6 +61,7 @@ def test_python_evaluation(testcase: DataDrivenTestCase) -> None:
             return
     else:
         interpreter = python3_path
+        mypy_cmdline.append('--python-version={}'.format('.'.join(map(str, PYTHON3_VERSION))))
 
     # Write the program to a file.
     program = '_' + testcase.name + '.py'

mypy/test/testsemanal.py

@@ -6,6 +6,7 @@
 
 from mypy import build
 from mypy.build import BuildSource
+from mypy.defaults import PYTHON3_VERSION
 from mypy.test.helpers import (
     assert_string_arrays_equal, normalize_error_messages, testfile_pyversion,
 )
@@ -38,6 +39,7 @@ def get_semanal_options() -> Options:
     options.use_builtins_fixtures = True
     options.semantic_analysis_only = True
     options.show_traceback = True
+    options.python_version = PYTHON3_VERSION
     return options
 
 

mypy/waiter.py

@@ -160,7 +160,7 @@ def load_log_file(self) -> Optional[List[Dict[str, Dict[str, Any]]]]:
                 test_log = json.load(fp)
         except FileNotFoundError:
             test_log = []
-        except json.JSONDecodeError:
+        except ValueError:
             print('corrupt test log file {}'.format(self.FULL_LOG_FILENAME), file=sys.stderr)
             test_log = []
         return test_log

runtests.py

@@ -78,9 +78,10 @@ def add_mypy_cmd(self, name: str, mypy_args: List[str], cwd: Optional[str] = Non
     def add_mypy(self, name: str, *args: str, cwd: Optional[str] = None) -> None:
         self.add_mypy_cmd(name, list(args), cwd=cwd)
 
-    def add_mypy_modules(self, name: str, modules: Iterable[str],
-                         cwd: Optional[str] = None) -> None:
-        args = list(itertools.chain(*(['-m', mod] for mod in modules)))
+    def add_mypy_modules(self, name: str, modules: Iterable[str], cwd: Optional[str] = None,
+                         extra_args: Optional[List[str]] = None) -> None:
+        args = extra_args or []
+        args.extend(list(itertools.chain(*(['-m', mod] for mod in modules))))
         self.add_mypy_cmd(name, args, cwd=cwd)
 
     def add_mypy_package(self, name: str, packagename: str, *flags: str) -> None:
@@ -256,7 +257,8 @@ def add_stubs(driver: Driver) -> None:
                 module = file_to_module(f[len(stubdir) + 1:])
                 modules.add(module)
 
-    driver.add_mypy_modules('stubs', sorted(modules))
+    # these require at least 3.5 otherwise it will fail trying to import zipapp
+    driver.add_mypy_modules('stubs', sorted(modules), extra_args=['--python-version=3.5'])
 
 
 def add_stdlibsamples(driver: Driver) -> None:
@@ -276,7 +278,11 @@ def add_stdlibsamples(driver: Driver) -> None:
 
 def add_samples(driver: Driver) -> None:
     for f in find_files(os.path.join('test-data', 'samples'), suffix='.py'):
-        driver.add_mypy('file %s' % f, f)
+        if f == os.path.join('test-data', 'samples', 'crawl2.py'):
+            # This test requires 3.5 for async functions
+            driver.add_mypy_cmd('file {}'.format(f), ['--python-version=3.5', f])
+        else:
+            driver.add_mypy('file %s' % f, f)
 
 
 def usage(status: int) -> None:

test-data/unit/cmdline.test

@@ -581,7 +581,7 @@ m.py:6: error: Explicit "Any" is not allowed
 m.py:9: error: Explicit "Any" is not allowed
 
 [case testDisallowAnyExplicitVarDeclaration]
-# cmd: mypy m.py
+# cmd: mypy --python-version=3.6 m.py
 
 [file mypy.ini]
 [[mypy]
@@ -601,7 +601,7 @@ m.py:3: error: Explicit "Any" is not allowed
 m.py:5: error: Explicit "Any" is not allowed
 
 [case testDisallowAnyExplicitGenericVarDeclaration]
-# cmd: mypy m.py
+# cmd: mypy --python-version=3.6 m.py
 
 [file mypy.ini]
 [[mypy]
@@ -785,7 +785,7 @@ N = TypedDict('N', {'x': str, 'y': List})  # no error
 m.py:4: error: Explicit "Any" is not allowed
 
 [case testDisallowAnyGenericsTupleNoTypeParams]
-# cmd: mypy m.py
+# cmd: mypy --python-version=3.6 m.py
 [file mypy.ini]
 [[mypy]
 [[mypy-m]
@@ -821,7 +821,7 @@ def g(s: List[Tuple[str, str]]) -> None: pass  # no error
 m.py:3: error: Missing type parameters for generic type
 
 [case testDisallowAnyGenericsTypeType]
-# cmd: mypy m.py
+# cmd: mypy --python-version=3.6 m.py
 [file mypy.ini]
 [[mypy]
 [[mypy-m]
@@ -858,7 +858,7 @@ def g(l: L[str]) -> None: pass  # no error
 m.py:5: error: Missing type parameters for generic type
 
 [case testDisallowAnyGenericsGenericAlias]
-# cmd: mypy m.py
+# cmd: mypy --python-version=3.6 m.py
 [file mypy.ini]
 [[mypy]
 [[mypy-m]
@@ -882,7 +882,7 @@ m.py:7: error: Missing type parameters for generic type
 m.py:11: error: Missing type parameters for generic type
 
 [case testDisallowAnyGenericsPlainList]
-# cmd: mypy m.py
+# cmd: mypy --python-version=3.6 m.py
 [file mypy.ini]
 [[mypy]
 [[mypy-m]
@@ -906,7 +906,7 @@ m.py:8: error: Need type annotation for 'x'
 m.py:9: error: Missing type parameters for generic type
 
 [case testDisallowAnyGenericsCustomGenericClass]
-# cmd: mypy m.py
+# cmd: mypy --python-version=3.6 m.py
 [file mypy.ini]
 [[mypy]
 [[mypy-m]

test-data/unit/reports.test

@@ -281,7 +281,7 @@ Total      0      16    100.00%
 
 
 [case testAnyExpressionsReportTypesOfAny]
-# cmd: mypy --any-exprs-report report n.py
+# cmd: mypy --python-version=3.6 --any-exprs-report report n.py
 
 [file n.py]
 from typing import Any, List