Add test for pywrapper script
This adds some test coverage for the autodetecting Python toolchain (excludes Windows). Also added improved error handling in the script under test.
Fixes #7843.
RELNOTES: None
PiperOrigin-RevId: 245241521
diff --git a/src/test/py/bazel/BUILD b/src/test/py/bazel/BUILD
index 31432e1..e1cc9ea 100644
--- a/src/test/py/bazel/BUILD
+++ b/src/test/py/bazel/BUILD
@@ -23,6 +23,7 @@
"//third_party/def_parser:__pkg__",
"//tools/android:__pkg__",
"//tools/build_rules:__pkg__",
+ "//tools/python:__pkg__",
],
)
diff --git a/tools/python/BUILD b/tools/python/BUILD
index 2bdfb3e..04d9c23 100644
--- a/tools/python/BUILD
+++ b/tools/python/BUILD
@@ -1,3 +1,5 @@
+load(":utils.bzl", "expand_pyversion_template")
+
package(default_visibility = ["//visibility:public"])
filegroup(
@@ -22,3 +24,19 @@
],
visibility = ["//tools:__pkg__"],
)
+
+expand_pyversion_template(
+ name = "_generate_wrappers",
+ out2 = ":py2wrapper.sh",
+ out3 = ":py3wrapper.sh",
+ template = "pywrapper_template.txt",
+ visibility = ["//visibility:private"],
+)
+
+py_test(
+ name = "pywrapper_test",
+ srcs = ["pywrapper_test.py"],
+ data = [":py2wrapper.sh"],
+ python_version = "PY2",
+ deps = ["//src/test/py/bazel:test_base"],
+)
diff --git a/tools/python/pywrapper_template.txt b/tools/python/pywrapper_template.txt
index 0b73fa0..be85c69 100644
--- a/tools/python/pywrapper_template.txt
+++ b/tools/python/pywrapper_template.txt
@@ -1,18 +1,22 @@
-#!/bin/sh -eu
+#!/bin/sh -u
+# Don't set -e because we don't have robust trapping and printing of errors.
-# Use /bin/sh rather than /bin/bash for portability. See discussion here:
+# We use /bin/sh rather than /bin/bash for portability. See discussion here:
# https://groups.google.com/forum/?nomobile=true#!topic/bazel-dev/4Ql_7eDcLC0
# We do lose the ability to set -o pipefail.
# TODO(#7843): integration tests for failure to find python / wrong version
# found / error while trying to print version
-GENERAL_FAILURE_MESSAGE="Error: The default python toolchain \
-(@bazel_tools//tools/python:autodetecting_toolchain) was unable to locate a \
-suitable Python interpreter on the target platform at execution time. Please \
-register an appropriate Python toolchain. See the documentation for \
-py_runtime_pair here:
-https://github.com/bazelbuild/bazel/blob/master/tools/python/toolchain.bzl."
+FAILURE_HEADER="\
+Error occurred while attempting to use the default Python toolchain \
+(@bazel_tools//tools/python:autodetecting_toolchain)."
+
+die() {
+ echo "$FAILURE_HEADER" 1>&2
+ echo "$1" 1>&2
+ exit 1
+}
# Try the "python%VERSION%" command name first, then fall back on "python".
PYTHON_BIN=`which python%VERSION% || echo ""`
@@ -22,20 +26,30 @@
USED_FALLBACK=1
fi
if [ -z "${PYTHON_BIN:-}" ]; then
- echo "$GENERAL_FAILURE_MESSAGE"
- echo "Failure reason: Cannot locate 'python%VERSION%' or 'python' on the \
-target platform's PATH, which is:
-$PATH"
- exit 1
+ die "Neither 'python%VERSION%' nor 'python' were found on the target \
+platform's PATH, which is:
+
+$PATH
+
+Please ensure an interpreter is available on this platform (and marked \
+executable), or else register an appropriate Python toolchain as per the \
+documentation for py_runtime_pair \
+(https://github.com/bazelbuild/bazel/blob/master/tools/python/toolchain.bzl)."
fi
# Verify that we grabbed an interpreter with the right version.
-VERSION_STR=`"$PYTHON_BIN" -V 2>&1`
+VERSION_STR=`"$PYTHON_BIN" -V 2>&1` \
+ || die "Could not get interpreter version via '$PYTHON_BIN -V'"
if ! echo "$VERSION_STR" | grep -q " %VERSION%\." ; then
- echo "$GENERAL_FAILURE_MESSAGE"
- echo "Failure reason: According to '$PYTHON_BIN -V', version is \
-'$VERSION_STR', but we need version %VERSION%"
- exit 1
+ die "According to '$PYTHON_BIN -V', version is '$VERSION_STR', but we \
+need version %VERSION%. PATH is:
+
+$PATH
+
+Please ensure an interpreter with version %VERSION% is available on this \
+platform as 'python%VERSION%' or 'python', or else register an appropriate \
+Python toolchain as per the documentation for py_runtime_pair \
+(https://github.com/bazelbuild/bazel/blob/master/tools/python/toolchain.bzl)."
fi
exec "$PYTHON_BIN" "$@"
diff --git a/tools/python/pywrapper_test.py b/tools/python/pywrapper_test.py
new file mode 100644
index 0000000..fa41239
--- /dev/null
+++ b/tools/python/pywrapper_test.py
@@ -0,0 +1,195 @@
+# pylint: disable=g-bad-file-header
+# Copyright 2019 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import print_function
+
+import os
+import subprocess
+import textwrap
+import unittest
+
+from src.test.py.bazel import test_base
+
+
+class MockPythonLines(object):
+
+ NORMAL = textwrap.dedent(r"""\
+ if [ "$1" = "-V" ]; then
+ echo "Mock Python 2.xyz!"
+ else
+ echo "I am mock Python!"
+ fi
+ """).split("\n")
+
+ FAIL = textwrap.dedent(r"""\
+ echo "Mock failure!"
+ exit 1
+ """).split("\n")
+
+ WRONG_VERSION = textwrap.dedent(r"""\
+ if [ "$1" = "-V" ]; then
+ echo "Mock Python 3.xyz!"
+ else
+ echo "I am mock Python!"
+ fi
+ """).split("\n")
+
+ VERSION_ERROR = textwrap.dedent(r"""\
+ if [ "$1" = "-V" ]; then
+ echo "Error!"
+ exit 1
+ else
+ echo "I am mock Python!"
+ fi
+ """).split("\n")
+
+
+# TODO(brandjon): Switch to shutil.which when the test is moved to PY3.
+def which(cmd):
+ """A poor man's approximation of `shutil.which()` or the `which` command.
+
+ Args:
+ cmd: The command (executable) name to lookup; should not contain path
+ separators
+
+ Returns:
+ The absolute path to the first match in PATH, or None if not found.
+ """
+ for p in os.environ["PATH"].split(os.pathsep):
+ fullpath = os.path.abspath(os.path.join(p, cmd))
+ if os.path.exists(fullpath):
+ return fullpath
+ return None
+
+
+# TODO(brandjon): Move this test to PY3. Blocked (ironically!) on the fix for
+# #4815 being available in the host version of Bazel used to run this test.
+class PywrapperTest(test_base.TestBase):
+ """Unit tests for pywrapper_template.txt.
+
+ These tests are based on the instantiation of the template for Python 2. They
+ ensure that the wrapper can locate, validate, and launch a Python 2 executable
+ on PATH. To ensure hermeticity, the tests launch the wrapper with PATH
+ restricted to the scratch directory.
+
+ Unix only.
+ """
+
+ def setup_tool(self, cmd):
+ """Copies a command from its system location to the test directory."""
+ path = which(cmd)
+ self.assertIsNotNone(
+ path, msg="Could not locate '%s' command on PATH" % cmd)
+ self.CopyFile(path, os.path.join("dir", cmd), executable=True)
+
+ def setUp(self):
+ super(PywrapperTest, self).setUp()
+
+ # Locate script under test.
+ wrapper_path = self.Rlocation("io_bazel/tools/python/py2wrapper.sh")
+ self.assertIsNotNone(
+ wrapper_path, msg="Could not locate py2wrapper.sh in runfiles")
+ self.wrapper_path = wrapper_path
+
+ # Setup scratch directory with all executables the script depends on.
+ #
+ # This is brittle, but we need to make sure we can run the script when only
+ # the scratch directory is on PATH, so that we can control whether or not
+ # the python executables exist on PATH.
+ self.setup_tool("which")
+ self.setup_tool("echo")
+ self.setup_tool("grep")
+
+ def run_wrapper(self, title_for_logging=None):
+ new_env = dict(os.environ)
+ new_env["PATH"] = self.Path("dir")
+ proc = subprocess.Popen([self.wrapper_path],
+ stdout=subprocess.PIPE,
+ stderr=subprocess.PIPE,
+ universal_newlines=True,
+ cwd=self.Path("dir"),
+ env=new_env)
+ # TODO(brandjon): Add a timeout arg here when upgraded to PY3.
+ out, err = proc.communicate()
+ if title_for_logging is not None:
+ print(textwrap.dedent("""\
+ ----------------
+ %s
+ Exit code: %d
+ stdout:
+ %s
+ stderr:
+ %s
+ ----------------
+ """) % (title_for_logging, proc.returncode, out, err))
+ return proc.returncode, out, err
+
+ def assert_wrapper_success(self, returncode, out, err):
+ self.assertEqual(returncode, 0, msg="Expected to exit without error")
+ self.assertEqual(
+ out, "I am mock Python!\n", msg="stdout was not as expected")
+ self.assertEqual(err, "", msg="Expected to produce no stderr output")
+
+ def assert_wrapper_failure(self, returncode, out, err, message):
+ self.assertEqual(returncode, 1, msg="Expected to exit with error code 1")
+ self.assertRegexpMatches(
+ err, message, msg="stderr did not contain expected string")
+
+ def test_finds_python2(self):
+ self.ScratchFile("dir/python2", MockPythonLines.NORMAL, executable=True)
+ returncode, out, err = self.run_wrapper("test_finds_python2")
+ self.assert_wrapper_success(returncode, out, err)
+
+ def test_finds_python(self):
+ self.ScratchFile("dir/python", MockPythonLines.NORMAL, executable=True)
+ returncode, out, err = self.run_wrapper("test_finds_python")
+ self.assert_wrapper_success(returncode, out, err)
+
+ def test_prefers_python2(self):
+ self.ScratchFile("dir/python2", MockPythonLines.NORMAL, executable=True)
+ self.ScratchFile("dir/python", MockPythonLines.FAIL, executable=True)
+ returncode, out, err = self.run_wrapper("test_prefers_python2")
+ self.assert_wrapper_success(returncode, out, err)
+
+ def test_no_interpreter_found(self):
+ returncode, out, err = self.run_wrapper("test_no_interpreter_found")
+ self.assert_wrapper_failure(returncode, out, err,
+ "Neither 'python2' nor 'python' were found")
+
+ def test_wrong_version(self):
+ self.ScratchFile(
+ "dir/python2", MockPythonLines.WRONG_VERSION, executable=True)
+ returncode, out, err = self.run_wrapper("test_wrong_version")
+ self.assert_wrapper_failure(
+ returncode, out, err,
+ "version is 'Mock Python 3.xyz!', but we need version 2")
+
+ def test_error_getting_version(self):
+ self.ScratchFile(
+ "dir/python2", MockPythonLines.VERSION_ERROR, executable=True)
+ returncode, out, err = self.run_wrapper("test_error_getting_version")
+ self.assert_wrapper_failure(returncode, out, err,
+ "Could not get interpreter version")
+
+ def test_interpreter_not_executable(self):
+ self.ScratchFile(
+ "dir/python2", MockPythonLines.VERSION_ERROR, executable=False)
+ returncode, out, err = self.run_wrapper("test_interpreter_not_executable")
+ self.assert_wrapper_failure(returncode, out, err,
+ "Neither 'python2' nor 'python' were found")
+
+
+if __name__ == "__main__":
+ unittest.main()
