Update pytype_test to be easier to run manually. (#2469)

* Moves the pytype installation to requirements-tests-py3.txt, now
  that pytype can run under Python 3.5+.
* Changes tests/pytype_test.py to not require a --python{version}-exe
  argument when it can automatically find the Python interpreter, and
  cleans up a few typos and out-of-date things.
* Updates the appropriate documentation.
* Updates .travis.yml.

.travis.yml

@@ -6,20 +6,19 @@ matrix:
     - python: "3.6-dev"
       env: TEST_CMD="flake8"
     - python: "3.6"
+      env: TEST_CMD="./tests/pytype_test.py --num-parallel=4"
+    - python: "3.5-dev"
       env: TEST_CMD="./tests/mypy_selftest.py"
     - python: "3.5"
       env: TEST_CMD="./tests/mypy_test.py"
     - python: "3.4"
       env: TEST_CMD="./tests/check_consistent.py"
-    - python: "2.7"
-      env: TEST_CMD="./tests/pytype_test.py --num-parallel=4"
-      sudo: true
 
 install:
-  # pytype needs py-2.7, mypy needs py-3.3+. Additional logic in runtests.py
+  # pytype needs py-3.6, mypy needs py-3.3+. Additional logic in runtests.py
   - if [[ $TRAVIS_PYTHON_VERSION == '3.6-dev' ]]; then pip install -r requirements-tests-py3.txt; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == '3.6' ]]; then pip install -r requirements-tests-py3.txt; fi
   - if [[ $TRAVIS_PYTHON_VERSION == '3.5' ]]; then pip install -U git+git://github.com/python/mypy git+git://github.com/python/typed_ast; fi
-  - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then pip install -r requirements-tests-py2.txt; wget https://s3.amazonaws.com/travis-python-archives/binaries/ubuntu/14.04/x86_64/python-3.6.tar.bz2; sudo tar xjf python-3.6.tar.bz2 --directory /; fi
 
 script:
   - $TEST_CMD

README.md

@@ -114,8 +114,8 @@ $ source .venv3/bin/activate
 (.venv3)$ pip3 install -r requirements-tests-py3.txt
 ```
 This will install mypy (you need the latest master branch from GitHub),
-typed-ast, and flake8. You can then run mypy tests and flake8 tests by
-invoking:
+typed-ast, flake8, and pytype. You can then run mypy, flake8, and pytype tests
+by invoking:
 ```
 (.venv3)$ python3 tests/mypy_test.py
 ...
@@ -123,21 +123,13 @@ invoking:
 ...
 (.venv3)$ flake8
 ...
+(.venv3)$ python3 tests/pytype_test.py
+...
 ```
-(Note that flake8 only works with Python 3.6 or higher.)
-
-To run the pytype tests, you need a separate virtual environment with
-Python 2.7, and a Python 3.6 interpreter somewhere you can point to. Run:
-```
-$ virtualenv --python=python2.7 .venv2
-$ source .venv2/bin/activate
-(.venv2)$ pip install -r requirements-tests-py2.txt
-```
-This will install pytype from its GitHub repo. You can then run pytype
-tests by running:
-```
-(.venv2)$ python tests/pytype_test.py --python36-exe=/path/to/python3.6
-```
+Note that flake8 only works with Python 3.6 or higher, and that to run the
+pytype tests, you will need Python 2.7 and Python 3.6 interpreters. Pytype will
+find these automatically if they're in `PATH`, but otherwise you must point to
+them with the `--python27-exe` and `--python36-exe` arguments, respectively.
 
 For mypy, if you are in the typeshed repo that is submodule of the
 mypy repo (so `..` refers to the mypy repo), there's a shortcut to run

requirements-tests-py2.txt

@@ -1 +0,0 @@
-pytype>=2018.6.19

requirements-tests-py3.txt

@@ -3,3 +3,4 @@ typed-ast>=1.0.4
 flake8==3.5.0
 flake8-bugbear==18.2.0
 flake8-pyi>=18.3.1
+pytype>=2018.9.19

tests/pytype_test.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 r"""Test runner for typeshed.
 
-Depends on mypy and pytype being installed.
+Depends on pytype being installed.
 
 If pytype is installed:
     1. For every pyi, do nothing if it is in pytype_blacklist.txt.
@@ -9,7 +9,7 @@ If pytype is installed:
       "pytd <foo.pyi>" in a separate process.
     3. If the file is not in the blacklist run
       "pytype --typeshed-location=typeshed_location --module-name=foo \
-      --convert-to-pickle=tmp_file <foo.pyi>.
+      --parse-pyi <foo.pyi>.
 Option two will parse the file, mostly syntactical correctness. Option three
 will load the file and all the builtins, typeshed dependencies. This will
 also discover incorrect usage of imported modules.
@@ -37,9 +37,10 @@ parser.add_argument('--pytype-bin-dir', type=str, default='',
 # Set to true to print a stack trace every time an exception is thrown.
 parser.add_argument('--print-stderr', type=bool, default=False,
                     help='Print stderr every time an error is encountered.')
-# We need to invoke python3.6. The default here works with our travis tests.
-parser.add_argument('--python36-exe', type=str,
-                    default='/opt/python/3.6/bin/python3.6',
+# We need to invoke python2.7 and 3.6.
+parser.add_argument('--python27-exe', type=str, default='python2.7',
+                    help='Path to a python 2.7 interpreter.')
+parser.add_argument('--python36-exe', type=str, default='python3.6',
                     help='Path to a python 3.6 interpreter.')
 
 Dirs = collections.namedtuple('Dirs', ['pytype', 'typeshed'])
@@ -165,7 +166,7 @@ def pytype_test(args):
     for p in paths:
         if not os.path.isdir(p):
             print('Cannot find typeshed subdir at %s '
-                  '(specify parent dir via --typeshed_location)' % p)
+                  '(specify parent dir via --typeshed-location)' % p)
             return 0, 0
 
     if can_run(dirs.pytype, 'pytd', '-h'):
@@ -176,10 +177,14 @@ def pytype_test(args):
         print('Cannot run pytd. Did you install pytype?')
         return 0, 0
 
-    if not can_run('', args.python36_exe, '--version'):
-        print('Cannot run python3.6 from %s. (point to a valid executable via '
-              '--python36-exe)' % args.python36_exe)
-        return 0, 0
+    for python_version_str in ('27', '36'):
+        dest = 'python%s_exe' % python_version_str
+        version = '.'.join(list(python_version_str))
+        arg = '--python%s-exe' % python_version_str
+        if not can_run('', getattr(args, dest), '--version'):
+            print('Cannot run Python {version}. (point to a valid executable '
+                  'via {arg})'.format(version=version, arg=arg))
+            return 0, 0
 
     # TODO(rchen152): Keep expanding our third_party/ coverage so we can move
     # to a small blacklist rather than an ever-growing whitelist.
@@ -200,16 +205,19 @@ def pytype_test(args):
     bad = []
 
     def _make_test(filename, major_version):
+        if major_version == 3:
+            version = '3.6'
+            exe = args.python36_exe
+        else:
+            version = '2.7'
+            exe = args.python27_exe
         run_cmd = [
             pytype_exe,
             '--module-name=%s' % _get_module_name(filename),
             '--parse-pyi',
+            '-V %s' % version,
+            '--python_exe=%s' % exe,
         ]
-        if major_version == 3:
-            run_cmd += [
-                '-V 3.6',
-                '--python_exe=%s' % args.python36_exe,
-            ]
         return BinaryRun(run_cmd + [filename],
                          dry_run=args.dry_run,
                          env={"TYPESHED_HOME": dirs.typeshed})